To investigate the interactions of ultrasonic waves with biological tissues, we developed and sta... more To investigate the interactions of ultrasonic waves with biological tissues, we developed and standardized several in vitro models. Using these systems - artificial stones, human erythrocytes, L1210 mouse leukemia cells, multicellular spheroids, cavitation assay - we are able to elucidate the mechanisms of interaction as well as the cause of clinically observed side effects.
Extracorporeal shock wave lithotripsy (ESWL) has become the clinical standard method for non-inva... more Extracorporeal shock wave lithotripsy (ESWL) has become the clinical standard method for non-invasive disintegration not only of concrements in kidney and urinary tract but also of gallstones. Despite the widespread clinical use of ESWL, the mechanism of stone destruction is not yet really understood, but several possibilities (cavitation, shock wave reflection) are discussed. The final cause of various side effects is still under discussion. Nevertheless, during the last few years much effort was put into possible extensions of ESWL applications On the other hand , physical characterizations of shock waves are rarely reported and combined measurements of biological effects in vitro and physical characterization of the applied shock waves are not available. We, therefore, examined the influence of water temperature and gas content on the shock wave efficency in biological systems and determined several physical characteristics (pressure amplitudes, rise time etc.) of the shock waves...
Jeder kennt ihn, viele besitzen ihn: den Badeschwamm. Doch Schwamme sind von weit hoherem Nutzen:... more Jeder kennt ihn, viele besitzen ihn: den Badeschwamm. Doch Schwamme sind von weit hoherem Nutzen: Sie produzieren eine Vielzahl bioaktiver Substanzen von grosem pharmazeutischen Wert. Im Meer schutzen sich die festgewachsenen Schwamme dadurch vor dem Gefressen- und Uberwachsenwerden. Aber auch beim Kampf um neuen Lebensraum, zum Beispiel im dichtbesiedelten Korallenriff, werden die chemischen „Kampfstoffe“ eingesetzt (Abb. 1,2). Diese Substanzen konnen bisher jedoch nicht in grosem Masstab gewonnen und genutzt werden. Abhilfe konnen neue Methoden zur Kultivierung von Schwammen im Meer und in Aquarien sowie zur Zuchtung von Schwammzellen in der Petrischale oder im Bioreaktor leisten. Erstmals wird in einem bundesweiten Projekt die nachhaltige Nutzung mariner Schwamme in Zusammenarbeit mit internationalen Gruppen fokussiert. Durch die Bundelung und Vernetzung der Kompetenzen sollen die ersten Erfolge der am Forschungsvorhaben BIOTECmarin beteiligten Gruppen weiterentwickelt werden, Ex...
Extracorporeal lithotripsy has been successfully established, based on different principles of ge... more Extracorporeal lithotripsy has been successfully established, based on different principles of generating and focusing the shock waves. Lithotripters have also been used to investigate the influence of shocks to cancer cells and solid tumors. With two different trans-mitters (spark-gap type XL-1 and piezo-resonance type MW 2) we applied shock waves and short high power US-pulses to suspended and immobilized tumor cells and multicell spheroids. With MW 2 significant local damage on cell spheroids in gelatin was achieved, caused by locally controlled cavitation. The results are compared to each other.
Three-dimensional, spherical aggregates of cells - so-called multicell spheroids - have many prac... more Three-dimensional, spherical aggregates of cells - so-called multicell spheroids - have many practical applications. In cancer research, for example, they contribute to a drastic reduction in the number of experiments with animals. The authors of the following article were awarded a special DM 10,000 prize under the Felix-Wankel-Tierschutz-Forschungspreis in November 1986 for their work on intercellular communication in multicell spheroids.
In a two-dimensionally growing monolayer the same morphological structure as in vivo may be detec... more In a two-dimensionally growing monolayer the same morphological structure as in vivo may be detected, however, as we have shown for gap junctions, their regulatory activity may be retarded. Cells growing in three-dimensional multicell-spheroids may re-establish their regulatory activities and, therefore, match the in vivo conditions more closely. Multicell-spheroids enable in vitro investigations on differentiating systems and on interactions between normal and malignant cells, thus substituting costly in vivo experiments. Am Beispiel der gap junctions haben wir gezeigt, das im zweidimensionalen Monolayer-Wachstum durchaus die gleichen morphologischen Strukturen wie in-vivo gefunden werden, ihre funktionellen Aktivitaten jedoch verkummert sein konnen. Im dreidimensionalen in-vitro Wachstum werden Regulationsleistungen jedoch reaktiviert und dadurch in-vivo Verhaltnisse besser angenahert. Daher konnen mit solchen Multizell-Spharoiden Untersuchungen zur Differenzierung und Interaktion...
We examined the cytotoxic effect of shock waves for primary (embryonic chick kidney and thigh mus... more We examined the cytotoxic effect of shock waves for primary (embryonic chick kidney and thigh muscle) and permanently growing normal and malignant cells (human, rat, and mouse) in suspension. To avoid the influence of different media, the cells were suspended in phosphate buffered saline and shock wave treated. In all cases the acute cytotoxic effect (measured by flow cytometry) was a function of the applied shock waves. The investigated cells differed in their LD 50 values which, however, do not reveal a general difference in sensitivity to shock waves for normal and malignant cells.
The application of extracorporeal generated shock waves in medicine for the fragmentation of huma... more The application of extracorporeal generated shock waves in medicine for the fragmentation of human kidney and gall stones proved to be a very successful technique. Sbock wave lithotripsy, however, is not free of tissue damaging side effects. One major mechanism for the fragmentation of stones as well as for the side effects is cavitation, ie. the formation and movement of bubbles in liquids exposed to tensile forces. Collapse of cavitation hubbIes is accompanied by local "bot spots" of several 1,000 K, thus generating free radicals. We investigated the contribution of these free radicals to cellular injury by varying the cellular amount of a well known scavenger of free radicals, a-tocopherol.
The sessile suspension-feeding wormsnailDendropoma maxima, Sowerby 1825 (Vermetidae) secretes a m... more The sessile suspension-feeding wormsnailDendropoma maxima, Sowerby 1825 (Vermetidae) secretes a mucus net to capture planktonic prey. The nets are spread out over the corals and often have remarkable deleterious effects on them like changes in growth form and pigmentation shifts not uncommonly resulting in tissue necrosis. Until now, there is no explanation for this phenomenon although the indication as well as theories about its genesis is mentioned in several publications. Vermetids are well studied concerning the intraspecific competition with neighboring individuals but not in their interaction with other taxa like corals or fish. We did extensivein situvideo recording and observed that fish avoided the plankton-load nets although several specialized taxa are known to be molluscivores, mucivores, and/or feed on plankton. As many molluscs use chemical weapons to combat feeding pressure and to defend themselves against predators, we screened empty and plankton-load mucus nets for ...
Symsagittifera roscoffensis is a plathelminth living in symbiosis with the green algae Tetraselmi... more Symsagittifera roscoffensis is a plathelminth living in symbiosis with the green algae Tetraselmis convolutae. Host and symbiont are a model system for the study of endosymbiosis, so far mainly focused on their biochemical interactions. S. roscoffensis is well known for its positive phototaxis that is hypothesized to optimize the symbiont's light perception for photosynthesis. In this study, we conducted a detailed analysis of phototaxis using light sources of different wavelength and brightness by videotracking. Furthermore, we compared the behavioral data with the electron transfer rate of the photosystem from cultured symbiotic cells. The symbiotic algae is adapted to low light conditions showing a positive electron transfer rate (ETR) already at a photosynthetically active radiation (PAR) of 0.112 µmol m(-2) s(-1) (mol photons per square meter and second), and S. roscoffensis showed a positive phototactic behaviour for light intensities up to 459.17 µmol m(-2) s(-1) which ar...
pfaffenwaldring 57, 0-7000 Stuttgart 80, Fed. Rep. Germany Stone fragmentation in extracorporeal ... more pfaffenwaldring 57, 0-7000 Stuttgart 80, Fed. Rep. Germany Stone fragmentation in extracorporeal shock wave lithotripsy as well as accompanying tissue damage are attributed to cavitation. We attempted to demonstrate and localize the occurrence of cavitation in cell-free solutions and MGH-UI cells using sensitive dyes for the detection of cavitation-generated free radicals.
SUMMARY Many limno-terrestrial tardigrades live in unstable habitats where they experience extrem... more SUMMARY Many limno-terrestrial tardigrades live in unstable habitats where they experience extreme environmental conditions such as drought, heat and subzero temperatures. Although their stress tolerance is often related only to the anhydrobiotic state, tardigrades can also be exposed to great daily temperature fluctuations without dehydration. Survival of subzero temperatures in an active state requires either the ability to tolerate the freezing of body water or mechanisms to decrease the freezing point. Considering freeze tolerance in tardigrades as a general feature, we studied the survival rate of nine tardigrade species originating from polar, temperate and tropical regions by cooling them at rates of 9, 7, 5, 3 and 1°C h–1 down to –30°C then returning them to room temperature at 10°C h–1. The resulting moderate survival after fast and slow cooling rates and low survival after intermediate cooling rates may indicate the influence of a physical effect during fast cooling and th...
The International Journal of Developmental Biology, 2009
Sponges (Porifera) are currently considered to be the first branch off the Urmetazoa, common ance... more Sponges (Porifera) are currently considered to be the first branch off the Urmetazoa, common ancestors of all multicellular animals or metazoa. Research in the field of the developmental biology of sponges was restricted to morphological observations. Nowadays, research is mainly concentrated on larval development, primarily dealing with tissue formation. Already since 1907, methods for developing functional sponges from stem cells have been at hand. Functional freshwater sponges can be grown from stem cell populations originating from gemmulae. A number of poriferan sequences with high similarity to regulative genes in higher metazoa have already been found. We have now succeeded in heterologously expressing the red fluorescent protein DsRedN1 under the control of the cytomegalovirus promoter in young specimens of the freshwater sponge Spongilla lacustris. The protein folded correctly, polymerized and subsequently was detected by fluorescence microscopy. Reporting this expression system, we now consider this appealing system for early meatazoan development to be ready for molecular developmental biology and functional genetics research.
Bereits 1970 konnte durch in virro Versuche gezeigt werden. daß sich Nierensteine mit Stoßwellen.... more Bereits 1970 konnte durch in virro Versuche gezeigt werden. daß sich Nierensteine mit Stoßwellen. welche sich in Wasser ausbreiten, zerkleinern Ias.sc:n 111/. In den fol• genden Jahren wurde ein System entwickelt (Unterwasser• Funkenstrecke) 110/. mit dem 1980 die ersten Nierensteine durch extrakorporale Stoßwellenlithotripsie erfolgreich behandelt wurden 151. In der Zwischenzeit ist dieses Ver
Total amounts and patterns of bromoisoxazoline alkaloids of Aplysina sponges from Croatia (Medite... more Total amounts and patterns of bromoisoxazoline alkaloids of Aplysina sponges from Croatia (Mediterranean Sea) were analyzed along an underwater slope ranging from 1.8 to 38.5 m. Total amounts of alkaloids varied from sample to sample and showed no correlation with depth. In contrast, striking differences of alkaloid patterns were found between sponges from shallow sites (1.8 - 11.8 m) and those collected from deeper sites (11.8 - 38.5 m). Sponges from shallow depths consistently exhibited alkaloid patterns typical for Aplysina aerophoba with aerophobin-2 (2) and isofistularin-3 (3) as main constituents. Sponges from deeper sites (below 11.8 m) resembled Aplysina cavernicola with aerothionin (4) and aplysinamisin- 1 (1) as major compounds. The typical A. cavernicola pigment 3,4-dihydroxyquinoline- 2-carboxylic acid (6), however, could not be detected in A. aerophoba sponges but was replaced by the A. aerophoba pigment uranidine (5) which appeared to be present in all sponge samples a...
Extracorporeally generated shock waves used in lithotripsy of urinary and biliary stones exhibit ... more Extracorporeally generated shock waves used in lithotripsy of urinary and biliary stones exhibit tissue lesions in viva and destroy or damage cells in vitro. The involvement of cavitation-generated free radicals in these harmful effects is discussed controversially. We investigated changes in cytoplasmic calcium concentration and intracellular calcium localization after shock-wave treatment of suspended cell cultures using flow cytometry and electron microscopy and present evidence for the disturbance of mitochondrial Ca2+ sequestration and, therefore, for a chemically induced cell injury.
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2010
In tardigrades, tolerance to low temperature is well known and allows them to cope with subzero t... more In tardigrades, tolerance to low temperature is well known and allows them to cope with subzero temperatures in their environment. Although the ability to tolerate freezing body water has been demonstrated in some tardigrades, freeze tolerance of embryonic stages has been little studied, although this has ecological significance. In this study, we evaluated the subzero temperature survival of five different developmental stages of the eutardigrade species Milnesium tardigradum after freezing to −30°C. Embryos were exposed to five different cooling rates between room temperature and −30°C at 1°C/h, 3°C/h, 5°C/h, 7°C/h, and 9°C/h followed by a warming period at 10°C/h. The results showed that the developmental stage and the cooling rate have a significant effect on the hatching rate. Less developed embryonic stages were more sensitive to freezing at higher freezing rates than more developed stages. Differential Scanning Calorimetry (DSC) was used to determine the temperature of crystallization (Tc) in single embryos of the different developmental stages and revealed no differences between the stages. Based on the calorimetric data, we also conclude that the ice nucleation is homogeneous in embryonic stages in tardigrades, as also recently shown for fully developed tardigrades, and not triggered by nucleating agents.
Survival in microhabitats that experience extreme fluctuations in water availability and temperat... more Survival in microhabitats that experience extreme fluctuations in water availability and temperature requires special adaptations. To withstand such environmental conditions, tardigrades, as well as some nematodes and rotifers, enter a completely desiccated state known as anhydrobiosis. We examined the effects of high temperatures on fully desiccated (anhydrobiotic) tardigrades. Nine species from the classes Heterotardigrada and Eutardigrada were exposed to temperatures of up to 110 degrees C for 1 h. Exposure to temperatures of up to 80 degrees C resulted in a moderate decrease in survival. Exposure to temperatures above this resulted in a sharp decrease in survival, with no animals of the families Macrobiotidae and Echiniscidae surviving 100 degrees C. However, Milnesium tardigradum (Milnesidae) showed survival of >90% after exposure to 100 degrees C; temperatures above this resulted in a steep decrease in survival. Vitrification is assumed to play a major role in the survival of anhydrobiotic organisms during exposure to extreme temperatures, and consequently, the glass-transition temperature (T(g)) is critical to high-temperature tolerance. In this study, we provide the first evidence of the presence of a glass transition during heating in an anhydrobiotic tardigrade through the use of differential scanning calorimetry.
To investigate the interactions of ultrasonic waves with biological tissues, we developed and sta... more To investigate the interactions of ultrasonic waves with biological tissues, we developed and standardized several in vitro models. Using these systems - artificial stones, human erythrocytes, L1210 mouse leukemia cells, multicellular spheroids, cavitation assay - we are able to elucidate the mechanisms of interaction as well as the cause of clinically observed side effects.
Extracorporeal shock wave lithotripsy (ESWL) has become the clinical standard method for non-inva... more Extracorporeal shock wave lithotripsy (ESWL) has become the clinical standard method for non-invasive disintegration not only of concrements in kidney and urinary tract but also of gallstones. Despite the widespread clinical use of ESWL, the mechanism of stone destruction is not yet really understood, but several possibilities (cavitation, shock wave reflection) are discussed. The final cause of various side effects is still under discussion. Nevertheless, during the last few years much effort was put into possible extensions of ESWL applications On the other hand , physical characterizations of shock waves are rarely reported and combined measurements of biological effects in vitro and physical characterization of the applied shock waves are not available. We, therefore, examined the influence of water temperature and gas content on the shock wave efficency in biological systems and determined several physical characteristics (pressure amplitudes, rise time etc.) of the shock waves...
Jeder kennt ihn, viele besitzen ihn: den Badeschwamm. Doch Schwamme sind von weit hoherem Nutzen:... more Jeder kennt ihn, viele besitzen ihn: den Badeschwamm. Doch Schwamme sind von weit hoherem Nutzen: Sie produzieren eine Vielzahl bioaktiver Substanzen von grosem pharmazeutischen Wert. Im Meer schutzen sich die festgewachsenen Schwamme dadurch vor dem Gefressen- und Uberwachsenwerden. Aber auch beim Kampf um neuen Lebensraum, zum Beispiel im dichtbesiedelten Korallenriff, werden die chemischen „Kampfstoffe“ eingesetzt (Abb. 1,2). Diese Substanzen konnen bisher jedoch nicht in grosem Masstab gewonnen und genutzt werden. Abhilfe konnen neue Methoden zur Kultivierung von Schwammen im Meer und in Aquarien sowie zur Zuchtung von Schwammzellen in der Petrischale oder im Bioreaktor leisten. Erstmals wird in einem bundesweiten Projekt die nachhaltige Nutzung mariner Schwamme in Zusammenarbeit mit internationalen Gruppen fokussiert. Durch die Bundelung und Vernetzung der Kompetenzen sollen die ersten Erfolge der am Forschungsvorhaben BIOTECmarin beteiligten Gruppen weiterentwickelt werden, Ex...
Extracorporeal lithotripsy has been successfully established, based on different principles of ge... more Extracorporeal lithotripsy has been successfully established, based on different principles of generating and focusing the shock waves. Lithotripters have also been used to investigate the influence of shocks to cancer cells and solid tumors. With two different trans-mitters (spark-gap type XL-1 and piezo-resonance type MW 2) we applied shock waves and short high power US-pulses to suspended and immobilized tumor cells and multicell spheroids. With MW 2 significant local damage on cell spheroids in gelatin was achieved, caused by locally controlled cavitation. The results are compared to each other.
Three-dimensional, spherical aggregates of cells - so-called multicell spheroids - have many prac... more Three-dimensional, spherical aggregates of cells - so-called multicell spheroids - have many practical applications. In cancer research, for example, they contribute to a drastic reduction in the number of experiments with animals. The authors of the following article were awarded a special DM 10,000 prize under the Felix-Wankel-Tierschutz-Forschungspreis in November 1986 for their work on intercellular communication in multicell spheroids.
In a two-dimensionally growing monolayer the same morphological structure as in vivo may be detec... more In a two-dimensionally growing monolayer the same morphological structure as in vivo may be detected, however, as we have shown for gap junctions, their regulatory activity may be retarded. Cells growing in three-dimensional multicell-spheroids may re-establish their regulatory activities and, therefore, match the in vivo conditions more closely. Multicell-spheroids enable in vitro investigations on differentiating systems and on interactions between normal and malignant cells, thus substituting costly in vivo experiments. Am Beispiel der gap junctions haben wir gezeigt, das im zweidimensionalen Monolayer-Wachstum durchaus die gleichen morphologischen Strukturen wie in-vivo gefunden werden, ihre funktionellen Aktivitaten jedoch verkummert sein konnen. Im dreidimensionalen in-vitro Wachstum werden Regulationsleistungen jedoch reaktiviert und dadurch in-vivo Verhaltnisse besser angenahert. Daher konnen mit solchen Multizell-Spharoiden Untersuchungen zur Differenzierung und Interaktion...
We examined the cytotoxic effect of shock waves for primary (embryonic chick kidney and thigh mus... more We examined the cytotoxic effect of shock waves for primary (embryonic chick kidney and thigh muscle) and permanently growing normal and malignant cells (human, rat, and mouse) in suspension. To avoid the influence of different media, the cells were suspended in phosphate buffered saline and shock wave treated. In all cases the acute cytotoxic effect (measured by flow cytometry) was a function of the applied shock waves. The investigated cells differed in their LD 50 values which, however, do not reveal a general difference in sensitivity to shock waves for normal and malignant cells.
The application of extracorporeal generated shock waves in medicine for the fragmentation of huma... more The application of extracorporeal generated shock waves in medicine for the fragmentation of human kidney and gall stones proved to be a very successful technique. Sbock wave lithotripsy, however, is not free of tissue damaging side effects. One major mechanism for the fragmentation of stones as well as for the side effects is cavitation, ie. the formation and movement of bubbles in liquids exposed to tensile forces. Collapse of cavitation hubbIes is accompanied by local "bot spots" of several 1,000 K, thus generating free radicals. We investigated the contribution of these free radicals to cellular injury by varying the cellular amount of a well known scavenger of free radicals, a-tocopherol.
The sessile suspension-feeding wormsnailDendropoma maxima, Sowerby 1825 (Vermetidae) secretes a m... more The sessile suspension-feeding wormsnailDendropoma maxima, Sowerby 1825 (Vermetidae) secretes a mucus net to capture planktonic prey. The nets are spread out over the corals and often have remarkable deleterious effects on them like changes in growth form and pigmentation shifts not uncommonly resulting in tissue necrosis. Until now, there is no explanation for this phenomenon although the indication as well as theories about its genesis is mentioned in several publications. Vermetids are well studied concerning the intraspecific competition with neighboring individuals but not in their interaction with other taxa like corals or fish. We did extensivein situvideo recording and observed that fish avoided the plankton-load nets although several specialized taxa are known to be molluscivores, mucivores, and/or feed on plankton. As many molluscs use chemical weapons to combat feeding pressure and to defend themselves against predators, we screened empty and plankton-load mucus nets for ...
Symsagittifera roscoffensis is a plathelminth living in symbiosis with the green algae Tetraselmi... more Symsagittifera roscoffensis is a plathelminth living in symbiosis with the green algae Tetraselmis convolutae. Host and symbiont are a model system for the study of endosymbiosis, so far mainly focused on their biochemical interactions. S. roscoffensis is well known for its positive phototaxis that is hypothesized to optimize the symbiont's light perception for photosynthesis. In this study, we conducted a detailed analysis of phototaxis using light sources of different wavelength and brightness by videotracking. Furthermore, we compared the behavioral data with the electron transfer rate of the photosystem from cultured symbiotic cells. The symbiotic algae is adapted to low light conditions showing a positive electron transfer rate (ETR) already at a photosynthetically active radiation (PAR) of 0.112 µmol m(-2) s(-1) (mol photons per square meter and second), and S. roscoffensis showed a positive phototactic behaviour for light intensities up to 459.17 µmol m(-2) s(-1) which ar...
pfaffenwaldring 57, 0-7000 Stuttgart 80, Fed. Rep. Germany Stone fragmentation in extracorporeal ... more pfaffenwaldring 57, 0-7000 Stuttgart 80, Fed. Rep. Germany Stone fragmentation in extracorporeal shock wave lithotripsy as well as accompanying tissue damage are attributed to cavitation. We attempted to demonstrate and localize the occurrence of cavitation in cell-free solutions and MGH-UI cells using sensitive dyes for the detection of cavitation-generated free radicals.
SUMMARY Many limno-terrestrial tardigrades live in unstable habitats where they experience extrem... more SUMMARY Many limno-terrestrial tardigrades live in unstable habitats where they experience extreme environmental conditions such as drought, heat and subzero temperatures. Although their stress tolerance is often related only to the anhydrobiotic state, tardigrades can also be exposed to great daily temperature fluctuations without dehydration. Survival of subzero temperatures in an active state requires either the ability to tolerate the freezing of body water or mechanisms to decrease the freezing point. Considering freeze tolerance in tardigrades as a general feature, we studied the survival rate of nine tardigrade species originating from polar, temperate and tropical regions by cooling them at rates of 9, 7, 5, 3 and 1°C h–1 down to –30°C then returning them to room temperature at 10°C h–1. The resulting moderate survival after fast and slow cooling rates and low survival after intermediate cooling rates may indicate the influence of a physical effect during fast cooling and th...
The International Journal of Developmental Biology, 2009
Sponges (Porifera) are currently considered to be the first branch off the Urmetazoa, common ance... more Sponges (Porifera) are currently considered to be the first branch off the Urmetazoa, common ancestors of all multicellular animals or metazoa. Research in the field of the developmental biology of sponges was restricted to morphological observations. Nowadays, research is mainly concentrated on larval development, primarily dealing with tissue formation. Already since 1907, methods for developing functional sponges from stem cells have been at hand. Functional freshwater sponges can be grown from stem cell populations originating from gemmulae. A number of poriferan sequences with high similarity to regulative genes in higher metazoa have already been found. We have now succeeded in heterologously expressing the red fluorescent protein DsRedN1 under the control of the cytomegalovirus promoter in young specimens of the freshwater sponge Spongilla lacustris. The protein folded correctly, polymerized and subsequently was detected by fluorescence microscopy. Reporting this expression system, we now consider this appealing system for early meatazoan development to be ready for molecular developmental biology and functional genetics research.
Bereits 1970 konnte durch in virro Versuche gezeigt werden. daß sich Nierensteine mit Stoßwellen.... more Bereits 1970 konnte durch in virro Versuche gezeigt werden. daß sich Nierensteine mit Stoßwellen. welche sich in Wasser ausbreiten, zerkleinern Ias.sc:n 111/. In den fol• genden Jahren wurde ein System entwickelt (Unterwasser• Funkenstrecke) 110/. mit dem 1980 die ersten Nierensteine durch extrakorporale Stoßwellenlithotripsie erfolgreich behandelt wurden 151. In der Zwischenzeit ist dieses Ver
Total amounts and patterns of bromoisoxazoline alkaloids of Aplysina sponges from Croatia (Medite... more Total amounts and patterns of bromoisoxazoline alkaloids of Aplysina sponges from Croatia (Mediterranean Sea) were analyzed along an underwater slope ranging from 1.8 to 38.5 m. Total amounts of alkaloids varied from sample to sample and showed no correlation with depth. In contrast, striking differences of alkaloid patterns were found between sponges from shallow sites (1.8 - 11.8 m) and those collected from deeper sites (11.8 - 38.5 m). Sponges from shallow depths consistently exhibited alkaloid patterns typical for Aplysina aerophoba with aerophobin-2 (2) and isofistularin-3 (3) as main constituents. Sponges from deeper sites (below 11.8 m) resembled Aplysina cavernicola with aerothionin (4) and aplysinamisin- 1 (1) as major compounds. The typical A. cavernicola pigment 3,4-dihydroxyquinoline- 2-carboxylic acid (6), however, could not be detected in A. aerophoba sponges but was replaced by the A. aerophoba pigment uranidine (5) which appeared to be present in all sponge samples a...
Extracorporeally generated shock waves used in lithotripsy of urinary and biliary stones exhibit ... more Extracorporeally generated shock waves used in lithotripsy of urinary and biliary stones exhibit tissue lesions in viva and destroy or damage cells in vitro. The involvement of cavitation-generated free radicals in these harmful effects is discussed controversially. We investigated changes in cytoplasmic calcium concentration and intracellular calcium localization after shock-wave treatment of suspended cell cultures using flow cytometry and electron microscopy and present evidence for the disturbance of mitochondrial Ca2+ sequestration and, therefore, for a chemically induced cell injury.
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2010
In tardigrades, tolerance to low temperature is well known and allows them to cope with subzero t... more In tardigrades, tolerance to low temperature is well known and allows them to cope with subzero temperatures in their environment. Although the ability to tolerate freezing body water has been demonstrated in some tardigrades, freeze tolerance of embryonic stages has been little studied, although this has ecological significance. In this study, we evaluated the subzero temperature survival of five different developmental stages of the eutardigrade species Milnesium tardigradum after freezing to −30°C. Embryos were exposed to five different cooling rates between room temperature and −30°C at 1°C/h, 3°C/h, 5°C/h, 7°C/h, and 9°C/h followed by a warming period at 10°C/h. The results showed that the developmental stage and the cooling rate have a significant effect on the hatching rate. Less developed embryonic stages were more sensitive to freezing at higher freezing rates than more developed stages. Differential Scanning Calorimetry (DSC) was used to determine the temperature of crystallization (Tc) in single embryos of the different developmental stages and revealed no differences between the stages. Based on the calorimetric data, we also conclude that the ice nucleation is homogeneous in embryonic stages in tardigrades, as also recently shown for fully developed tardigrades, and not triggered by nucleating agents.
Survival in microhabitats that experience extreme fluctuations in water availability and temperat... more Survival in microhabitats that experience extreme fluctuations in water availability and temperature requires special adaptations. To withstand such environmental conditions, tardigrades, as well as some nematodes and rotifers, enter a completely desiccated state known as anhydrobiosis. We examined the effects of high temperatures on fully desiccated (anhydrobiotic) tardigrades. Nine species from the classes Heterotardigrada and Eutardigrada were exposed to temperatures of up to 110 degrees C for 1 h. Exposure to temperatures of up to 80 degrees C resulted in a moderate decrease in survival. Exposure to temperatures above this resulted in a sharp decrease in survival, with no animals of the families Macrobiotidae and Echiniscidae surviving 100 degrees C. However, Milnesium tardigradum (Milnesidae) showed survival of >90% after exposure to 100 degrees C; temperatures above this resulted in a steep decrease in survival. Vitrification is assumed to play a major role in the survival of anhydrobiotic organisms during exposure to extreme temperatures, and consequently, the glass-transition temperature (T(g)) is critical to high-temperature tolerance. In this study, we provide the first evidence of the presence of a glass transition during heating in an anhydrobiotic tardigrade through the use of differential scanning calorimetry.
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Papers by Franz Brümmer