Effects of magnetic fluid hyperthermia (MFH) on C3H mammary carcinoma in vivo

Magnetic fluids (MF) have a potential for hyperthermia due to their good power absorption capabilities. Recent in vitro experiments with the so-called 'Magnetic Fluid Hyperthermia (MFH)' have shown that human tumours cells are homogeneously inactivated after AC magnetic field excitation of extracellular MF. The aim of the present study was the evaluation of a high dose MFH on intramuscularly implanted mammary carcinoma of the mouse. The tumours originated from initial in vivo passages of a spontaneous parent tumour. Because of larger variations of tumour growth in this rather primary model, logistic regression of non-averaged volumes was performed for each treatment modality. All growing tumours were randomized 30 days after transplantation (day of treatment) with an overall size distribution between 120-400 mm3. An intratumoural steady state temperature of 47 +/- 1.0 degrees C was maintained for 30 minutes with whole-body AC magnetic fields of 6-12.5 kA/m at 520 kHz. The magnetic fluid was #P6, which is a high biocompatible dextran magnetite. #P6 was given intratumourally (1.5 x 10(-2) mg ferrite/mm3) 20-30 minutes before excitation and was combined with magnetic targeting (50 mT), which yielded a 2.5-fold enhancement of the intratumoural iron concentration. Histological examinations of tumour tissue after intralesional ferrofluid administration alone indicated deep infiltration of the fluid into the carcinoma tissue, but no evidence of tissue damage as compared with untreated controls. In contrast, widespread tumour necrosis was observed after MFH. After application of either dextran or ferrofluid alone (no difference, p = 0.665), tumour growth was slightly delayed in comparison with untreated controls (p < 0.001). In contrast to the good fit of the controls (R = 0.92-0.87), tumour growth after MFH was much more heterogeneous; some tumours showed no evidence for regrowth at 50 days whereas others had grown quite readily. This most probably reflected the critical problem of homogeneity of the intratumoural MF distribution, which was also confirmed qualitatively by Magnetic Resonance Imaging (MRI), heterogeneous pigmentation of MFH treated tumours, and up to 1 degree C differences between temperature probes in the same tumour during AC magnetic field application. However, a quantitative comparison between intratumoural MF-heterogeneity and tumour response could not be performed in this study. Despite these current limitations, the regression analysis of the MFH data yielded a smaller tumour volume of about 1000 mm3 at 50 days growth time in contrast to all three controls. In conclusion, encouraging results have been obtained, which show, that one single high dose MFH is already able to induce local tumour control in many cases within 30 days after treatment. To overcome the uncertainties of intratumoural MF heterogeneity, advanced intralesional application methods are currently under development.

Arrhenius analysis of the thermal response of human colonic adenocarcinoma cells in vitro using the multi-target, single-hit and the linear-quadratic model

In order to compare the intrinsic thermal sensitivity of different malignant cell lines the multi-target, single-hit model has been widely accepted. It is even applied in clinical hyperthermia by the so-called thermal isoeffect dose (TID) concept originated from this model. The second model which is preferentially used to describe radiation survival curves is the linear-quadratic (LQ) model which can be also applied to thermal response. Interestingly, no breaking point and different activation energies are obtained with this model. In the present paper we demonstrate this discrepancy with the two human colonic adenocarcinoma cell lines WiDr and SW620. Our results further validate the already earlier published persuasion, that neither the multi-target, single-hit model, nor the LQ model are adequate to describe hyperthermic survival. Since both models give completely different results, further data aquisition of isoeffect factors, breaking points and activation enthalpies based on the multi-target, single-hit model only, is unprofitable until advanced models of thermal inactivation have been developed.

Cellular uptake of magnetic fluid particles and their effects on human adenocarcinoma cells exposed to AC magnetic fields in vitro

Suspensions of coated superparamagnetic particles (magnetic fluids, MF) in AC magnetic fields have a pronounced specific absorption rate (SAR) per mass compared to multidomain particles. The aim of the present study was to investigate cellular uptake and the biological effects of AC magnetic field excited bio-compatible magnetic fluids on human carcinoma cells in vitro. One of the fluids tested was a dextran magnetite, which has a very low cyto-toxicity with survival fractions (SF) between 0.8 and 0.9 at concentrations of up to 5 mg ferrite per ml. Human carcinoma cells intracellularly accumulate up to 1 pg ferrite/cell which has been demonstrated by electron microscopy (TEM), X-ray spectroscopy and measurements of intracellular iron. It has been shown that the ferrite core is not altered intracellularly, but many of the dextran shells are degraded which yields particle chains and other aggregates observed in TEM. Semi-solid pellets of the tumour cells were treated with AC magnetic fields (520 kHz, 4-12.5 kA/m) or waterbath hyperthermia at 43 and 45 degrees C, in presence of extracellular and/or intracellular magnetic fluid particles. Although MF heating is produced from individual particles, the survival fractions of MF heated and water bath heated cells are equal. In fact, the extracellular MF particle distribution is homogeneous enough to obtain similar inactivation. In contrast to earlier reports intracellular dextran magnetite particles in AC magnetic fields did not induce cell inactivation. Since the amount of intracellular ferrite should be indeed large enough for cell inactivation, the loss of dextran shells is most probably the main cause of limited effectiveness of the intracellular magnetite particles. The present work has demonstrated that: (1) MFH is able to inactivate tumour cells in vitro to at least the same extent as water bath hyperthermia; and (2) that there is a sensitizer effect of ferrofluids at 43 degrees C probably caused by free ferric ions which induce oxidative stress; and (3) that there is no cytotoxic effect of intracellular dextran magnetite particles 30-180 min excited with AC magnetic fields used in this study. For the new method the term 'magnetic fluid hyperthermia (MFH)' is proposed.

Investigation of the thermal stability of Ni/C multilayers by X-ray methods

Microstructural properties of Ni/C multilayers prepared by PLD (pulsed laser deposition) have been investigated after heat treatment in vacuum at temperatures in the range of 50 degrees C to 500 degrees C. X-ray diffractometry, X-ray reflectometry, fluorescence EXAFS (extended X-ray absorption fine structure) and HREM (high resolution transmission electron microscopy) have been applied to characterize samples in the initial state and after annealing. The multilayer reflectivity remained unchanged or increased at temperatures below 400 degrees C due to sharpening of the interfaces caused by the formation of alpha-nickel and nickel carbide. The reflectivity decreased at temperatures above 400 degrees C because of the fragmentation of the nickel layers. It can be shown, that both chemical and mechanical driving forces are responsible for the observed modifications of the initial specimen state.

Characterization of ultra smooth interfaces in Mo/Si-multilayers

The interface structure of Mo/Si-multilayers prepared by Pulsed Laser Deposition (PLD) on Si substrates at room temperature has been investigated. Already the in-situ ellipsometer data acquired during film growth indicate a particular behaviour of this material system that is caused by reaction/diffusion processes of the condensing atoms. MoSi(x) interlayers are formed both at the Mo on Si- and at the Si on Mo-interfaces. The results of multilayer characterization carried out by SNMS and RBS show similar concentration profiles for both types of the interlayers. More detailed information about interface structure and morphology can be provided by HREM investigations. In the TEM micrographs of various multilayers prepared for different laser light wavelengths an improvement of layer stack quality, i.e. formation of abrupt interfaces, with increasing photon energy is observed. Layer stacks having almost ideally smooth interfaces were synthesized by UV-photon ablation. HREM micrographs of these multilayers show a pronounced separation of spacer and absorber layers. The roughness sigma(R) of the interfaces between the amorphous Si- and MoSi(x)-layers was determined by image analysis. On the average a level sigma(R) approximately 0.1 nm is found. There is no indication for roughness replication or amplification from interface to interface as it is known from the appropriate products of conventional thin film technologies.

Recognition performance of subjects with color-vision deficiencies on a polychromatic sonar screen for ship navigation

To facilitate differentiation between objects that are approaching, stationary, and moving away, these objects are represented in different colors on the screens of sonar locating devices used in ship navigation. Yellow represents stationary objects, and represents approaching objects, and green represents those objects moving away. A total of 46 subjects with normal color vision and 184 individuals with color-vision deficiencies, among them 29 deuteranopic, 100 deuteranomalous, 21 protanopic and 34 protanomalous individuals, were investigated for their ability to identify different signals. Ten different objects were presented for a period of 64 s each. As a minimal requirement it was established that 50% of the respective experimental group be capable of recognizing the objects within half of this time. Whereas 73.3% of the subjects with normal color vision could meet this requirement, none of the subjects in the different groups with color-vision deficiencies could do so. Only 16.1% of the deuteranopic subjects, 33.1% of the deuteranomalous individuals, 16.2% of the protanopic subjects, and 37.6% of the protanomalous individuals detected all objects within 32 s. No appreciable difference in the ability to recognize signals occurred among the different groups of subjects with color-vision deficiencies.

Histology of tissue adjacent to an HAC-coated femoral prosthesis. A case report

We studied the fixation of a cementless titanium femoral prosthesis partially coated with hydroxyapatite ceramic (HAC) 10.4 months after implantation. Histomorphological investigation showed extensive new bone formation between the HAC coating and the bone bed; morphometry showed bone contact indices of up to 91.60%. There were a number of resorption lacunae on the HAC coat with depths of up to 76.6 microns and widths of up to 453 microns. Our results confirmed that considerable bone remodelling had taken place and that the apatite-coated prosthesis had united with bone despite the lack of appreciable immediate press-fit. Hydroxyapatite particles which had been released did not appear to show any negative effects on the stability of the implant.

Histology of tissue adjacent to an HAC-coated femoral prosthesis. A case report

We studied the fixation of a cementless titanium femoral prosthesis partially coated with hydroxyapatite ceramic (HAC) 10.4 months after implantation. Histomorphological investigation showed extensive new bone formation between the HAC coating and the bone bed; morphometry showed bone contact indices of up to 91.60%. There were a number of resorption lacunae on the HAC coat with depths of up to 76.6 microns and widths of up to 453 microns. Our results confirmed that considerable bone remodelling had taken place and that the apatite-coated prosthesis had united with bone despite the lack of appreciable immediate press-fit. Hydroxyapatite particles which had been released did not appear to show any negative effects on the stability of the implant.

[Visual acuity of military personnel with civilian or military driver's license on consulting an ophthalmologist]

Visual acuity was tested in 1861 members of the German armed forces who possessed military or civilian driving licences, first by means of a screening test (Roden-stock R12) and second by an ophthalmologist observing German Industrial Standard 58220, part 3. The tests were done with the patients wearing any corrective spectacles in use before the appointment. In 27.6% of all subjects the monocular or binocular visual acuity was less than 1.0. Binocular visual acuity less than 1.0 was found in 17.0%, less than 0.8 in 7.3% and less than 0.5 in 0.9%. After adjustment of the corrective lenses by the ophthalmologist these figures were reduced to visual acuity less than 1.0 in 1.6%, less than 0.8 in 0.4% and less than 0.5 in 0.1%. The frequency of suboptimal visual acuity showed no difference in driving licence classes. We found fewer cases of suboptimal visual acuity in our patients than Kratz and Häseker found in the civilian community in the study published in 1986. The age distribution was also different. In contrast to former publications, which showed an age-related progression, our population had the lowest number of subjects with subnormal visual acuity in the age group 35-45 years. The screening test for visual acuity and the test by the ophthalmologist showed the same results in 76.8% of cases.

Insulin-induced translocation of GLUT 4 in skeletal muscle of insulin-resistant Zucker rats

The genetically obese Zucker rat (fa/fa) is an animal model with severe insulin resistance of the skeletal muscle. We investigated whether a defect of insulin-dependent glucose transporter (GLUT 4) translocation might contribute to the pathogenesis of the insulin-resistant state. fa/fa rats, lean controls (Fa/Fa) as well as normal Wistar rats were injected intraperitoneally with insulin and were killed after 2 or 20 min, respectively. Subcellular fractions were prepared from hind-limb skeletal muscle and were characterized by determination of marker-enzyme activities and immunoblotting applying antibodies against alpha 1 Na+/K+ ATPase. The relative amounts of GLUT 1 and GLUT 4 were determined in the fractions by immunoblotting with the respective antibodies. Insulin induced an approximately two-fold increase of GLUT 4 in a plasma membrane and transverse tubule enriched fraction and a decrease in the low density enriched membrane fraction in all three groups of rats. There was a high individual variation in GLUT 4 translocation efficiency within the groups. However, no statistically significant difference was noted between the groups. No effect of insulin was detectable on the distribution of GLUT 1 or alpha 1 Na+K+ ATPase. The data suggest that skeletal muscle insulin resistance of obese Zucker rats is not associated with a lack of GLUT 4 translocation.

Soluble CD8, CD25 and CD30 antigens as prognostic markers in patients with untreated Hodgkin's lymphoma

In a search for serum markers with prognostic value and specificity for disease activity in Hodgkin's lymphoma, we evaluated the clinical significance of soluble suppressor/cytotoxic T-cell antigen (sCD8), soluble interleukin-2 receptor (sCD25) and soluble Hodgkin's associated antigen (sCD30) levels in the serum of 90 patients with untreated Hodgkin's lymphoma (HD). HD patients in advanced stages had significantly higher sCD8 and sCD25 levels than normal controls. The rate of detectable sCD30, which was absent in healthy controls, depended on stage and histological subtype, and was 22% for the entire group. Low sCD25 levels (< 1000 U/ml) predicted an excellent prognosis (100% event-free survival), while patients with high sCD8 levels (> 750 U/ml) or the demonstration of sCD30 had a poor outcome. Therefore, all three markers have prognostic significance. However, only sCD30 correlated strictly with disease activity and seems to be of value for the follow-up of patients in remission.

The clinical significance of cytokines and soluble forms of membrane-derived activation antigens in the serum of patients with Hodgkin's disease

In a search for specific serum markers with prognostic impact in Hodgkin's Disease (HD), we evaluated the clinical significance of several cytokines (IL-1 beta, IL-2, IL-3, IL-6, G-CSF, GM-CSF, TNF-alpha) and soluble forms of membrane-derived antigens (sCD4, sCD8, sCD23, sCD25, sCD30) in the serum of patients with untreated HD. Elevations of three groups of serum factors were observed: Firstly, elevations of the hematopoietic cytokines GM-CSF (detected in 39%), IL-6 (57%) and IL-3 (13%), which occurred simultaneously in the majority of the cases; secondly, simultaneous elevations of the inflammatory cytokines TNF-alpha and IL-1 beta (detected in 7%); and finally, elevations of membrane-derived activation antigens sCD8, sCD25, and sCD30. While the cytokine levels did not correlate with other obvious parameters, the membrane-derived activation antigens sCD8, sCD25 and sCD30 were associated with a poor prognosis. Only sCD30 correlated with disease activity and holds promise for the follow-up of patients in remission. Further investigations of these parameters at the cellular level might help to elucidate the enigmatic biology of HD.

Normal insulin receptor tyrosine kinase activity and glucose transporter (GLUT 4) levels in the skeletal muscle of hyperinsulinaemic hypertensive rats

The spontaneous hypertensive rat is an animal model characterized by a syndrome of hypertension, insulin resistance and hyperinsulinaemia. To elucidate whether in analogy to other insulin resistant animal models an inactivity of the insulin receptor kinase or an alteration of the glucose transporter (GLUT 4) level in the skeletal muscle might contribute to the pathogenesis of insulin resistance we determined insulin receptor kinase activity and GLUT 4 level in the hindlimbs of spontaneous hypertensive rats and normotensive control rats. Normotensive normoinsulinaemic Lewis and Wistar rats were used as insulin sensitive controls, obese Zucker rats were used as an insulin resistant control with known reduced skeletal muscle insulin receptor kinase activity. Binding of 125I-insulin, crosslinking of 125I-B26-insulin, autophosphorylation in vitro with 32P-ATP and phosphorylation of the synthetic substrate Poly (Glu 4: Tyr 1) were performed after partial purification of solubilized receptors on wheat germ agglutinin columns. GLUT 4 levels were determined by Western blotting of subcellular muscle membranes. Insulin receptors from spontaneous hypertensive rats compared to those from Lewis and Wistar rats showed no difference of the binding characteristics or the in vitro auto- and substrate phosphorylation activity of the receptor, while in the Zucker rats the earlier described insulin receptor kinase defect was clearly evident. Western blots of subcellular muscle membrane fractions with antibodies against GLUT 4 revealed no difference in transporter levels. These data suggest that insulin resistance in spontaneous hypertensive rats is caused neither by an insulin receptor inactivity nor by a decreased number of glucose transporters in the skeletal muscle.

Increased levels of circulating cytokines in patients with untreated Hodgkin's disease

Expression of several cytokines has been demonstrated in Hodgkin and Reed-Sternberg (H&RS) cells in vitro and in vivo. In order to determine whether interleukin-1 beta (IL-1 beta), IL-3, IL-6, GM-CSF, G-CSF, and TNF-alpha are elevated in Hodgkin's disease (HD), we tested the sera of untreated patients with HD by means of sensitive sandwich ELISAs. GM-CSF was detected in 22/56 patients (39%; range 40-140 pg/ml), IL-3 in 5/40 (13%; range 13-26 pg/ml), and IL-6 in 32/56 patients (57%; range 12-332 pg/ml). TNF-alpha and IL-1 beta were detected in only 3/43 patients (7%; range: TNF-alpha: 36-66 pg/ml; IL-1 beta: 389-1505 pg/ml) and G-CSF not at all. All patients with measurable IL-3 levels had both elevated IL-6 and GM-CSF levels, and the majority of patients with elevated IL-6 also had elevated GM-CSF levels and vice versa. In contrast, the 3/40 patients with both measurable IL-beta and TNF-alpha did not have elevated IL-3, IL-6, or GM-CSF levels. Cytokine levels were independent of stage or the presence of B-symptoms, and there was no correlation with any other clinical or laboratory parameter. Elevations of the respective cytokines might be a means to maintain normal blood cell counts in the respective patients with HD.

Olsalazine-related diarrhoea: does rat intestine adapt in vivo?

Diarrhoea may occur in up to 10% of patients with ulcerative colitis treated with olsalazine, the azolinked dimer of 5-aminosalicylic acid. However, this symptom often disappears despite continued drug medication. To examine reversibility of and adaptation to olsalazine effects on intestinal absorption, rats were fed olsalazine (4 mg/100 g body weight/day) for 0 (controls), 12, 24, and 32 days. Jejunal, ileal, and colonic loops were perfused in situ with buffer or olsalazine (11.6 mM) in a pendular perfusion system. Water and electrolyte absorption was inhibited in all intestinal segments (p less than 0.001). In the proximal small intestine, however, sodium absorption was inhibited by 61%, whereas chloride and potassium absorptions were turned into net secretion. In contrast, in ileal and colonic segments sodium, chloride, and potassium absorptions were turned into a net secretion. All inhibitory effects were reversible within a short time. Intestinal absorption remained inhibitable compared with controls (p = not significant) after chronic administration of olsalazine even for 1 month. Jejunal monosaccharide absorption was not altered by acute olsalazine perfusion. In the ileum, glucose absorption was significantly inhibited, but the inhibitory capacity of acute olsalazine application decreased significantly (p less than 0.05) depending on duration of olsalazine pretreatment (51% (controls) versus 38% (32 days)). These results point to a complex, acute, but fully reversible effect of olsalazine on intestinal passive and chloride-coupled absorptive processes. Since a mucosal adaptation to these diarrheogenic effects does not occur, the resulting increase in fluid load on the diseased colon may be important in the pathogenesis of olsalazine-related diarrhoea.

Increased levels of circulating interleukin-6 in patients with Hodgkin's disease

Expression of interleukin-6 (IL-6) and IL-6 receptors has been demonstrated in Hodgkin and Reed-Sternberg (H and RS) cells in vitro and in vivo. In order to evaluate the clinical significance of IL-6 serum levels in patients with Hodgkin's disease (HD), we tested the sera of 56 untreated patients with HD by means of a sensitive sandwich ELISA. While IL-6 was only rarely detectable in healthy controls or patients with non-Hodgkin's lymphoma, 32 of 56 patients (57 per cent) had detectable IL-6 levels (range 12-32 pg/ml). The rates of detectable IL-6 levels and the median levels were not correlated with age, sex, histological subtype, stage or the presence of B-symptoms, nor with any of a wide spectrum of laboratory parameters tested, including erythrocyte sedimentation rate, total leukocyte and lymphocyte counts, serum levels of soluble CD8, CD25 or CD30. The rates of complete remissions and freedom from treatment failure were not different in IL-6-negative and IL-6-positive patients. Except in one of 23 follow-up sera taken after therapy, IL-6 was no longer detectable even for patients who suffered from progressing disease, suggesting that the neoplastic H and RS cells are not the major source of circulating IL-6.

Susceptibility of Trichophyton rubrum to griseofulvin

Two hundred and seventy isolates of Trichophyton rubrum from 182 patients were subjected to susceptibility testing with griseofulvin according to Granade & Artis. A slight modification of the method concerning homogenization procedures gave better growth of controls in our investigation. In 245 cases an MIC could be determined. Among these isolates, seven strains from six patients presented MICs between 2 and 3 micrograms griseofulvin per ml, a value which, according to Artis et al., is to be considered as relatively resistant. The other isolates proved to be more susceptible to griseofulvin. Three of the patients showed no indication of therapeutic failure of griseofulvin treatment. The other three patients had onychomycoses of long standing and had been treated with griseofulvin previously with little or limited success. It is our conclusion that griseofulvin susceptibility testing is not a reliable instrument in explaining failure of griseofulvin therapy in Trichophyton rubrum mycoses.

[Intra- and extra-capsular condyle fractures in the growth period. Therapy, clinical course, complications]

37 patients had been reviewed after surgical (n = 25) or conservative (n = 12) treatment of condylar fractures. Morphologic and functional outcomes were equal in spite of the poorer starting position of the patients that had been operated on. Injuries and complications due to the operation, such as facial nerve palsy, growth inhibition or obvious scars have never been found. Conservatively treated and operated patients alike showed a moderate limitation of opening and mediotrusion on the fracture side, and both groups showed a flattening of the protrusion path.