[Magnetic thermotherapy of breast tumors: an experimental therapeutic approach]. / Magnetische Thermotherapie von Tumoren der Brust: ein experimenteller Therapieansatz.

The therapeutic strategy for breast cancer is changing, especially for early tumor stages with good prognosis. One potential minimally invasive therapy modality consists in the accumulation of a well-tolerated magnetic material (iron oxides, particularly magnetite) in the target tissue. By applying an alternating magnetic field, energy is selectively absorbed and induces harmful heating of the tumor. The present review deals with the essential conditions and parameters as studied in vitro and in vivo in animal experiments. Extrapolations to the clinical situation are discussed, in particular, the heating potential of the magnetic material, the selection of the magnetic field parameters, the occurrence of eddy currents, the generation of localized heating spots and the expected temperature rises and their effects on the tumor area.

Effects of magnetic thermoablation in muscle tissue using iron oxide particles: an in vitro study.

RATIONALE AND OBJECTIVES: To study the effects of magnetic thermoablation in muscle tissue from cow to assess interrelations that might be relevant for a minimally invasive therapy system in the long term. METHODS: Magnetite particles (50-180 mg) were placed in muscle tissue. Temperature elevations as a function of time and distance from the center of the magnetite deposition area were measured during the exposure (up to 304 seconds) to an alternating magnetic field (frequency 400 kHz, amplitude 6.5 kA/m) generated by a circular coil (diameter 90 mm). Measured curves were reproduced by numerical calculations. Tissue alterations, macroscopically visible as light-brown discoloration, were recorded by volume estimations and histopathologic studies. RESULTS: Significant temperature elevations (up to 87 degrees C) were reported within a distance of less than 15 mm from the magnetite deposition area. High initial heating rates were observed during the first 150 seconds of heating. The reproduction of the measured curves by numerical calculations was good (SD = 0.7 degrees C). The theoretical simulation was verified and applied to situations beyond the range of experimental conditions. Damaged tissue comprised pyknotic cell nuclei and degenerated myofibrils. Corresponding volumes were found to be up to 10 times higher than the volume of iron oxide dispersion. CONCLUSIONS: The data demonstrate the applicability of local magnetic thermoablation for therapy of muscle lesions in the long term.

Evaluation of temperature increase with different amounts of magnetite in liver tissue samples.

RATIONALE AND OBJECTIVES: The biologic effects of magnetically induced heating effects using iron oxide, magnetite, were examined in vitro in liver tissue samples as a first step toward potential applications in cancer therapy. METHODS: For the determination of the temperature profile around an iron oxide sample, a cylinder containing 170 mg of magnetite was constructed and placed into pureed liver tissue from pig, together with thermocouples of copper and constantan wires positioned at defined distances from it. Temperature measurements were performed during the exposure to an alternating magnetic field (frequency: 400 kHz; amplitude: approximately 6.5 kA/m) generated by a circular coil (90 mm of diameter). Moreover, variable amounts of magnetite (dissolved in approximately 0.2 mL physiologic saline) were injected directly into carrageenan gels. During the exposure to a magnetic field for 4 minutes the temperature increase was determined in the area of iron oxide deposition using a thermocouple. Additionally, variable amounts of magnetite were injected directly into isolated liver tissue samples (diameter: 20 mm; height: 30 mm) and exposed to a magnetic field for 2 minutes. The extent of the induced macroscopically visible tissue alterations (light brown colorations caused by heating) was examined by means of volume estimations. The degrees of cellular necrosis were investigated by histopathologic studies. RESULTS: The temperature profile around a magnetite cylinder revealed a significant decrease of temperature difference between the beginning and the end of heating, depending on increasing distance from the sample center. The extent of the temperature difference correlated with increasing heating time. No significant variations of temperature were observed at a distance of approximately 12 mm from the sample center. A good correlation (r = 0.98) between the injected amounts (31 to 200 mg) and the temperature increase since the start of heating (6.8-33.7 degrees C) in the area of iron oxide deposits was detected. The volume of damaged liver tissue was approximately seven times higher than the injected volume of iron oxide dispersion. Histologically different degrees of cellular necrosis were observed. CONCLUSIONS: The parameters determined in this article show that iron oxides are able to induce considerable heating effects in the surroundings. After an adequate optimization of the technical procedure, it is conceivable that heating properties of magnetites can be used in future cancer treatments.

[In vitro imaging of magnetite particles]. / Bildgebende Darstellung von Magnetiten in vitro.

PURPOSE: To find an optimal imaging modality for the assessment of magnetite agglomerations used as the heating sources during magnetic thermoablation of tumors. METHODS: 1 to 107 mg of coated (starch) magnetite particles were directly administered to an in vitro tumor model (swine lymph nodes) and investigated immediately (radiography) or after being embedded within a 4 % agar-phantom (sonography). T1-weighted MR images (TR = 400 ms, TE = 14 ms) were acquired from lymph nodes containing 0.5 to 25 mg magnetite. RESULTS: All investigated magnetite masses were qualitatively detectable by radiography. Sonographically, only mass agglomerations containing 107 mg magnetite were appropriately discernible. MRT images revealed distinct susceptibility artifacts. CONCLUSIONS: Based on the investigated imaging modalities, radiography is the method of choice for assessment of magnetite agglomerations using relevant dosages for magnetic thermoablation of tumors.

Use of magnetic nanoparticle heating in the treatment of breast cancer.

Magnetic nanoparticles are promising tools for the minimal invasive elimination of small tumours in the breast using magnetically-induced heating. The approach complies with the increasing demand for breast conserving therapies and has the advantage of offering a selective and refined tuning of the degree of energy deposition allowing an adequate temperature control at the target. The biophysical basis of the approach, the magnetic and structural properties of magnetic nanoparticles are reviewed. Results with model targets and in vivo experiments in laboratory animals are reported.

[Meaning of serotype Patoc (biflexa complex) for the diagnosis of leptospirosis by microscopic agglutination test (author's transl)]. / Die Bedeutung des Serotyps patoc (biflexa complex) für die Leptospirose-Diagnostik mit der Agglutinations-Lysis-Reaktion

Agglutination with serotype patoc (Patoc 1) was found in 72 of 125 cases of leptospirosis. Patoc-agglutination occured frequently in leptospirosis icterohaemorrhagiae, less frequently in leptospirosis grippotyphosa and rarely in leptospirosis tarassovi. 53 cases of leptospirosis were not diagnosed when using Patoc 1 as single antigen. So we cannot recommend to use serotype patoc as the sole antigen for microscopic agglutination test. We observed 1 case in which the reaction with Patoc 1 happened earlier than the reaction with the pathogen serotypes. For this reason the battery of antigens for carrying out microscopic agglutination test should include serotype patoc, too.

[Mycobacterial infections in internal medicine patients]. / Mykobakteriosen im internistischen Krankengut.

It is reported on four own observations of atypical mycobacteriosis, which had been evident within the clinical examinations of a larger mixed number of patients with internal diseases. In three patients pathogenic significance must be ascribed to the proved atypical mycobacteria. All the three had other basic diseases. Only in one patient it appeared as a purely pulmonary form of manifestation. On the basis of a further observation is shown that a single proof of atypical mycobacteria may be regarded only as accidental findings. The clinical symptomatology of this group of diseases is multiform. The differential-diagnostic considerations are usually determined by the basic disease. As apart from this the proof of atypical mycobacteria is difficult, infections with these microorganisms might at present not infrequently remain infrequently. The observation of a disease by mycobacterium xenopi emphasizes that also in this microorganism good chances of success may be given by medicamentous antituberculotic therapy.

[Precipitation reaction and hemagglutination-hemolysis reaction in tuberculosis. I. Precipitation reaction (author's transl)]. / Zur serologischen Diagnostik der Tuberkoluse mittels Präzipitationsreaktion und Hämagglutinations-Hmolysereaktion

Sera of patients, blood donors and cattle sera were examined by means of diffusion--in--gel technique using self produced antigens, prepared from H 37 Ra, one fresh isolated strain of M. tbc and BCG Jena. 38.2% of 421 patients with pulmonary tuberculosis reacted positive. Positive reactions were observed in 55.7% of 199 patients suffering from another infectious disease and in 31;7% of normal sera. Most precipitation lines were found with the antigen prepared from H37 Ra after incubation for 7 months. In human sera as well as in cattle a dependence of reactions upon mode of antigen production was evident.

[Precipitation reaction and hemagglutination-hemolysis reaction in tuberculosis. II. Hemagglutination-hemolysis reaction by Middlebrook-Dubos (author's transl)]. / Zur serologischen Diagnostik der Tuberkulose mittels Präzipitationsreaktion und Hämagglutinations-Hämolysereaktion. II. Mitteilung: Hämagglutinations-Hämolysereaktion nach Middlebrook-Dubos

Sera of patients with pulmonary and extrapulmonary tuberculosis, of blood donors and cattle sera were researched in hemagglutination reaction, using untreated and papain-treated sheep erythrocytes, and in hemolysis reaction. 58% of patients with pulmonary tuberculosis and 23% of normal sera, reacted positive in at least one of the 3 reactions. 24 sera of 44 patients with extrapulmonary tuberculosis were found to be positive. The titer is important for diagnosis. In normal sera the highest titers were 1:64 in all reactions. Titers of 1:128 are to be considered as proof of tuberculosis. Considering the height of titers the hemagglutination-hemolysis reaction can also be used for diagnosis of tuberculosis in cattle.

Electromagnetic heating of breast tumors in interventional radiology: in vitro and in vivo studies in human cadavers and mice.

PURPOSE: To assess relevant parameters for the minimally invasive elimination of breast tumors by using a selective application of magnetite and exposure of the breast to an alternating magnetic field. MATERIALS AND METHODS: The specific absorption rate (SAR) of different magnetite samples was determined calorimetrically. Temperature elevations based on magnetite mass (7-112 mg) and magnetic field amplitude (1.2-6.5 kA/m frequency, 400 kHz) were investigated by using human breast tissue. Parameter combinations (21 mg +/- 9 [SD], 242-second magnetic field exposure, 6.5-kA/m amplitude) were tested in 10 immunodeficient mice bearing human adenocarcinomas (MX-1 cells). Histologic sections of heated tumor tissue were analyzed. RESULTS: SAR data of different magnetite particle types ranged from 3 to 211 W/g. Temperature elevation (DeltaT) as a function of the magnetite mass increased linearly up to 28 mg; at higher masses, a saturation of DeltaT was observed at nearly 88 degrees C. The dependence of DeltaT on magnetic field amplitude (H) revealed a third-order power law: DeltaT = 0.26 degrees C/(kA/m)(3). H(3), with r(2) = 0.95. A mean temperature of 71 degrees C +/- 8 was recorded in the tumor region at the end of magnetic field exposure of the mice. Typical macroscopic findings included tumor shrinkage after heating. Histologically nuclear degenerations were observed in heated malignant cells. CONCLUSION: Magnetic heating of breast tumors is a promising technique for future interventional radiologic treatments.

[Molestation of patients and personnel in noise-exposed gynaecological hospital (author's transl)]. / Zur Lärmbelästigung von Patienten und Personal in einer lärmexponierten Frauenklinik.

Noise levels were measured in the Gynaecological Hospital of the University of Rostock. Patients, medical doctors, and nurses were interviewed on their own molestation. The equivalent permanent sound level, Leq, was 63.5 dB (AI) on average in patient rooms on daytime, while the average night value was 59.8 dB (AI). Maximum sound pressures, Lmax, varied between 55 and 80 dB (AI) in patient rooms. An Lmax of 85 dB (AI) was measured on a ward corridor, when instruments were cleaned in the wash-basin of a service room. Molestation by outdoor noise was reported by 88 per cent of 85 patients interviewed, while 29 per cent felt disturbed by indoor noise. The noise was perceived as disturbing also by the personnel. While the gravest role for the hospital investigated by played by outdoor noise, greatest attention should be given also to the control of indoor noise.

[Comparative study between the surface-active substances präwozell NBX (Nekal BX) and Ditalan WO hc for homogenization and decontamination of specimens for the cultivation of mycobacteria (author's transl)]. / Vergleich der ionenaktiven Netzmittel Präwozell NBX (Nekal BX) und Ditalan WO hc als Vorbehandlungsmittel zum kulturellen Nachweis von Mykobakterien.

In cooperation of eight laboratories the new surface-active substance Ditalan WO hc was compared with Präwozell NBX (Nekal BX) used for homogenization and decontamination of the specimens for culture investigations of mycobacteria in routine. Under routine conditions Ditalan showed a slight, but statistically not significant advantage. Out of 1672 specimens pretreated with both detergents 482 cultures were positive in all, 429 (89,0%) after homogenization with Ditalan and 413 (85,7%) after pretreatment with Präwozell. The rate of contamination of the cultures was low in both cases (about 0,5%). Ditalan had a better mucolytic effect than Präwozell. In quantitative investigations the number of positive cultures was equal with both methods, but the number of colonies was somewhat higher and the time of growth was a little shorter after using Ditalan. In the third part the influence of both detergent-reagent-solutions on mycobacteria of different species was compared to that of physiological sodium chloride solution. The rate of growth was decreased by both the detergents in nearly the same degree. But the damaging effect is caused less by the detergent itself than by the sodium hydroxide contained in the solution used for pretreatment of the specimens.