Helmut Breuninger

Die Ausbreitung von Tetracyclin im Innenohr nach unterschiedlicher Applikation im Mittelohr

SummaryIn 31 young healthy guinea pigs a 2% solution of tetracycline was introduced into the middle ear under urethane anesthesia. In one group tetracycline was filled in the tympanic cavity. In the other it was applied only to the round and oval windows. The solution was removed from the specimens after various periods of contact and the cochlea immediately frozen with liquid air. The head was then frozen, severed and mounted on the cryotome. The specimens were illuminated with ultraviolet light under the operating microscope. The distribution pattern of the tetracycline was determined in the following manner: Every 5 μm parallel to the modiolus a section of the labyrinth was cut away and the fluorescent face of the remaining specimen was examined and photographed. The results of each animal were recorded in diagram-form (Fig. 1). In this way, the liquid-spaces of the labyrinth and the brain remain closed throughout the application and evaluation phases of the experiment, and changes of pressure or direction of flow are excluded.In both test series the perilymph of the tympanic scale of the first coil showed a distinct fluorescence after every period of application.In the first series, in which the whole bulla was filled, tetracycline was detected after 10 min: (1) in all the scales of the first turn, (2) in the vestibule, (3) in the utricule and (4) in the two upper coils (Fig. 2a).After 30 min of application, fluorescence appeared in the whole cochlea and in the perilymphatic duct up to the subarachnoidal space (Fig. 2b). After 60 min the substance had diffused throughout all the lymphatic spaces of the inner ear, including the endolymphatic duct and sac (Fig. 2c). In addition, all the experiments of this series revealed the presence of tetracycline in the bony structure of the cochlea (Fig. 4a). The tangential cut through this structure showed a high concentration of tetracycline in its blood vessels (Fig. 5).In the second series, where tetracycline was applied only to the niches, a more sharply differentiated picture appeared. After 10 min fluorescence was observed in the first turn of the scala tympani and in the vestibule (Fig. 3a). After 1 h the substance had only penetrated the first quarter of the first coil, whereas it had already reached the subarachnoidal space via the perilymphatic duct (Fig. 3c). After 2 h the fluorescence appeared in addition in the endolymphatic duct and sac, in the utricule, and it had diffused both longitudinally and transversally throughout the first coil, but not beyond the beginning of the second coil (Fig. 3d). In contrast to the first series, no significant penetration of the bony capsule could be observed (Fig. 4b).These findings lead to the following conclusions:1.Low molecular substances reach the inner ear fluids very quickly through the round window membrane as well as through the stapes footplate and the cochlear bone.2.The transport of low molecular substances to the inner ear is facilitated by blood vessels in its bony capsule.3.The different invasion of the cochlea and the perilymphatic duct in the second series of experiments speaks for a drainage of the perilymph from the scala tympani into the subarachnoidal space.ZusammenfassungAn 31 ohrgesunden Meerschweinchen wurde Tetracyclin in gelöster Form in das Mittelohr appliziert. Dabei wurden entweder nur die beiden Fensternischen oder die gesamte Paukenhöhle gefüllt. Die gefrorenen Köpfe wurden im Kryotom geschnitten und im UV-Licht betrachtet. Auf diese Weise konnte das Tetracyclin im Innenohr nachgewiesen werden. Durch das Einfrieren des Kopfes wurden die Flüssigkeitsräume von Innenohr und Gehirn weder bei der Applikation noch bei der Auswertung eröffnet.Das Tetracyclin gelangt vor allem über das runde Fenster ins Innenohr. Außerdem kann es auch über das ovale Fenster in das Vestibulum eindringen. Als weitere Zugangswege kommen die Diffusion durch die knöcherne Labyrinthkapsel sowie der Transport über labyrinthdurchquerende Gefäße in Betracht. Von der ersten Windung der Scala tympani gelangt das Tetracyclin relativ schnell über den Aquaeductus cochleae in den Subarachnoidalraum.

Quantitative Bestimmung von Protein, Albumin und Antibiotika im Nasensekret gesunder Probanden

This study on the pharmacokinetics of antibiotics in nasal secretions was carried out with two orally applicable penicillin derivatives which show different resorption patterns. Each of the antibiotics (Ampicillin and Bacampicillin) was given in equimolar doses to 20 healthy young volunteers, with normal mucosa, in a double blind cross over fashion. Nasal secretions were collected 1, 2, 3, 4, 6, and 8 h after the application of a single dose to the overnight fasted persons. In 10 of them blood was taken at 0.5, 1, 1.5, 2, 3, and 4 h after the administration. For the sampling of the nasal secretions cotton wool was weighed together with an airtight vial containing 300 microliter of phosphate buffered saline (PBS). The dry cotton wool stayed in the nasal cavity for 20 min, was then put into the PBS and weighed again. The difference determines the amount of secretions collected. After 30 min the soaked cotton wool was pressed out into a vial with a sterile syringe. One hundred microliters of this solution was taken to determine the antibiotic concentration by a micromodification of the agar diffusion technique. In the remaining fluid total protein and albumin were quantitatively determined. The amount of nasal secretions which have been collected are, on average, independent of the time (Fig. 1). With rising secretion the protein content decreases (Fig. 5) as is the case with the albumin concentration. Regarding all persons, the protein content and albumin (Fig. 4) remain constant during the experiment from 8 a.m. to 4 p.m. The differences between the values shown in the figures are not significant. Comparing the mean concentration for the antibiotic at different times after the application, it is obvious that the agents show different curves (Fig. 6). With ampicillin the maximum of 0.13 microgram/ml is reached at 2 h after the administration whereas with becampicillin the maximum of 0.84 microgram/ml is reached after 1 h. The concentrations in the nasal secretions are clearly dependent of the serum values. In the serum the maximum of the mean values plotted against the time of 2.7 microgram/ml is to be found at 2 h, if ampicillin is given, whereas the maximum of 9.3 microgram/ml is reached at 1 h after bacampicillin administration. In both cases in serum and nasal secretions the mean concentration maximum is about three times higher after bacampicillin as compared with ampicillin. As a reference for the concentration of the antibiotic the total protein content of the sample is more suitable as compared with sample volume and albumin because of its easy and exact determination. The results show that the nasal secretions can be used as a model to evaluate the pharmacokinetics in the mucosa of the upper respiratory tract if an adequate number of test persons is used.SummaryThis study on the pharmacokinetics of antibiotics in nasal secretions was carried out with two orally applicable penicillin derivatives which show different resorption patterns. Each of the antibiotics (Ampicillin and Bacampicillin) was given in equimolar doses to 20 healthy young volunteers, with normal mucosa, in a double blind cross over fashion. Nasal secretions were collected 1, 2, 3, 4, 6, and 8 h after the application of a single dose to the overnight fasted persons. In 10 of them blood was taken at 0.5, 1, 1.5, 2, 3, and 4 h after the administration.For the sampling of the nasal secretions cotton wool was weighed together with an airtight vial containing 300 μl of phosphate buffered saline (PBS). The dry cotton wool stayed in the nasal cavity for 20 min, was then put into the PBS and weighed again. The difference determines the amount of secretions collected. After 30 min the soaked cotton wool was pressed out into a vial with a sterile syringe. One hundred microliters of this solution was taken to determine the antibiotic concentration by a micromodification of the agar diffusion technique. In the remaining fluid total protein and albumin were quantitatively determined. The amount of nasal secretions which have been collected are, on average, independent of the time (Fig. 1). With rising secretion the protein content decreases (Fig. 5) as is the case with the albumin concentration. Regarding all persons, the protein content and albumin (Fig. 4) remain constant during the experiment from 8 a.m. to 4 p.m. The differences between the values shown in the figures are not significant.Comparing the mean concentration for the antibiotic at different times after the application, it is obvious that the agents show different curves (Fig. 6). With ampicillin the maximum of 0.13 μg/ml is reached at 2 h after the administration whereas with becampicillin the maximum of 0.84 μg/ml is reached after 1 h. The concentrations in the nasal secretions are clearly dependent of the serum values. In the serum the maximum of the mean values plotted against the time of 2.7 μg/ml is to be found at 2 h, if ampicillin is given, whereas the maximum of 9.3 μg/ml is reached at 1 h after bacampicillin administration. In both cases in serum and nasal secretions the mean concentration maximum is about three times higher after bacampicillin as compared with ampicillin. As a reference for the concentration of the antibiotic the total protein content of the sample is more suitable as compared with sample volume and albumin because of its easy and exact determination. The results show that the nasal secretions can be used as a model to evaluate the pharmacokinetics in the mucosa of the upper respiratory tract if an adequate number of test persons is used.ZusammenfassungBei 20 gesunden Testpersonen wurden in einer Doppelblindstudie Ampicillin und Bacampicillin in einmaliger äquimolarer Dosis oral appliziert. Bei allen Versuchsteilnehmern wurde zu Versuchsbeginn sowie nach 1, 2, 3, 4, 6 und 8 h Nasensekret entnommen, dessen Menge durch Wiegen bestimmt wurde. In diesen Proben wurde der Albumin-und Gesamtproteingehalt sowie die Konzentration des Antibiotikums bestimmt. Bei 10 dieser Personen wurde zu Versuchsbeginn und nach 0,5, 1, 1,5, 2, 3 und 4 h Blut entnommen und im Serum der Antibiotikumspiegel ermittelt.Die Menge des Sekrets sowie die Konzentrationen von Albumin und Gesamtprotein weisen starke Schwankungen auf, bleiben im Mittelwert aber über die Versuchsdauer konstant.Im Nasensekret tritt das Maximum der mittleren Antibiotikakonzentration bei Ampicillin (0,13 μg/ml) nach 2 h auf, während es bei Bacampicillin (0,84 μg/ml) bereits nach 1 h vorliegt. Dieser Zeitverlauf und die Konzentrationsunterschiede sind vom Serumspiegel abhängig. Im Serum zeigen sich die Maxima der mittleren Antibiotikakonzentration bei Ampicillin (2,7 μg/ml) nach 2 h und bei Bacampicillin (9,3 μg/ml) nach 1 h. Sowohl die Penetration der Substanz über die Nasenschleimhaut in das Sekret, als auch die Elimination folgen dem Serumspiegel nur mit einer geringen zeitlichen Verzögerung.Als Bezugsgröße für die Antibiotikakonzentration im Nasensekret erscheint die Gesamtproteinmenge am besten geeignet, da die Bestimmung einfach und wenig störanfällig ist.

Über das Eindringen von tympanal appliziertem Tetracyclin in das Innenohr des Meerschweinchens

SummaryIn 31 young healthy guinea pigs a 2% solution of tetracycline was introduced into the middle ear under urethane anesthesia. In one group the tympanic cavity was filled with tetracycline. In the other tetracycline was applied only to the round and oval windows. The solution was removed from the specimens after various periods of contact and the cochlea immediately frozen with liquid air. The head then was frozen, severed and mounted on the cryotome. Every 5 μm parallel to the modiolus a section of the labyrinth was cut away and the fluorescent face of the remaining specimen was examined and photographed. In this way, the liquid spaces of the labyrinth and the brain remained closed throughout the application and evaluation phases of the experiment, and changes of pressure or direction of flow were excluded.In both test-series the perilymph of the scala tympani of the first coil showed a distinct fluorescence after every period of application. In the first series, in which the whole bulla was filled, tetracycline was also detected after 10 min in the vestibule and in the upper two coils, after 30 min in the perilymphatic duct up to the subarachnoidal space and after 1 h in the endolymphatic sac. All the experiments of this series revealed the presence of tetracycline in the bony strutcure of the cochlea and their blood vessels. In the second series, where tetracycline ] was applied only to the niches, it never reached the upper three coils of the cochlea. The invasion of the perilymphatic duct in both series indicates a drainage of the scala tympani into the subarachnoidal space. The finding that low molecular substances reach the inner ear fluids very quickly through the round and oval windows as well as through the cochlear bone and its blood vessels, is of clinical relevance to the application of toxic or therapeutic substances into the middle ear.

Quantitative Bestimmung von Protein, Albumin und Antibiotika im Nasensekret von Patienten mit akuter Sinusitis

SummaryForty outpatients with sinusitis were treated with equimolar doses of Ampicillin (556 mg) of Bacampicillin (800 mg) three times daily in a doubleblind fashion. To control the efficency of the therapy the number of leukocytes, sedimentation rate, subjective and objective symptmes were evaluated before the first dose and on the 2nd and 10th day. On the 1st day nasal secretions were collected at the time the first dose was given and 1, 2, and 3 h later. In these samples the concentrations of the antibiotic, of protein and albumin were determined. The amount of nasal secretions collected as well as the protein and albumin content remains fairly constant during the experiment.The concentration of Bacampicillin in nasal secretions reaches its maximum of 0.92 μg/ml 1h after the application whereas with Ampicillin it is 0.59 μg/ml after 2 h. These values correspond to the concentrations which were found in normal test persons. The clinical result of the therapy is slightly better with Bacampicillin only if patients with severe sinusitis were taken into account. In the patients with moderate or slight symptoms no difference was found. Two of the patients which were treated with Ampicillin had to stop the therapy because of severe diarrhoe. When using Bacampicillin no patients had diarrhoe. This study shows that Bacampicillin (as an inactive ester of Ampicillin) is resorbed quicker and gives higher concentrations in the nasal secretions. Thus, the therapeutic effect is better in severe cases as compared to Ampicillin. Moreover, the side effects are less.ZusammenfassungVierzig Patienten, die wegen Sinusitiden ambulant behandelt wurden, erhielten in einem Doppelblindverfahren dreimal täglich über fünf Tage äquimolare Dosen von Ampicillin (556 mg) oder Bacampicillin (800 mg). Zur Kontrolle des klinischen Verlaufs der Erkrankung bestimmte man zu Beginn der Therapie sowie nach 2 bzw. 10 Tagen die Leukozytenzahl im Blut und die Senkungsgeschwindigkeit. Außerdem wurden Kontrolluntersuchungen der subjektiven und objektivierbaren Symptome durchgeführt. Zu Versuchsbeginn, nach einer, zwei und nach drei Stunden maß man die Sekretmenge durch Wiegen, außerdem die Konzentration des Antibiotikums im Sekret, den Albumm und den Gesamtproteingehalt. Die Menge des Nasensekrets, der Albumin-und Proteingehalt sind über die Versuchsdauer hinweg praktisch als konstant anzuehen. Derselbe Befund wurde auch bei gesunden Probanden erhoben.Die mittlere Konzentration des Antibiotikums im Nasensekret weist nach Gabe von Bacampicillin ein Maximum von 0,92 μg/ml nach der ersten Stunde auf. Bei Ampicillin tritt der Höchstwert von 0,59 μg/ml nach zwei Stunden auf. Im Vergleich dazu findet man mit gesunden Probanden bei Ampicillin nach zwei Stunden ein Maximum von 0,13 μg/ml, bei Bacampicillin nach einer Stunde 0,84 μg/ml.Bei etwa gleicher Auswahl der Versuchsteilnehmer in Hinblick auf die Schwere der Sinusitis findet sich bei äquimolarer Dosierung bei den schweren Entzündungszuständen mit Bacampicillin ein besserer Therapieerfolg als mit Ampicillin, bei den mäßigen und leichten Verlaufsformen ist kein Unterschied festzustellen. Nach Gabe von Ampicillin mußte bei zwei Versuchsteilnehmern wegen starker Diarrhoe die Therapie abgebrochen werden, während dies bei Bacampicillin nicht der Fall ist, was auf eine bessere Verträglichkeit dieser Esterform hinweist.Forty outpatients with sinusitis were treated with equimolar doses of Ampicillin (556 mg) of Bacampicillin (800 mg) three times daily in a doubleblind fashion. To control the efficiency of the therapy the number of leukocytes, sedimentation rate, subjective and objective symptomes were evaluated before the first dose and on the 2nd and 10th day. On the 1st day nasal secretions were collected at the time the first dose was given and 1, 2, and 3 h later. In these samples the concentrations of the antibiotic, of protein and albumin were determined. The amount of nasal secretions collected as well as the protein and albumin content remains fairly constant during the experiment. The concentration of Bacampicillin in nasal secretions reaches its maximum of 0.92 microgram/ml 1 h after the application whereas with Ampicillin it is 0.59 microgram/ml after 2 h. These values correspond to the concentrations which were found in normal test persons. The clinical result of the therapy is slightly better with Bacampicillin only if patients with severe sinusitis were taken into account. In the patients with moderate or slight symptoms no difference was found. Two of the patients which were treated with Ampicillin had to stop the therapy because of severe diarrhoe. When using Bacampicillin no patients had diarrhoe. This study shows that Bacampicillin (as an inactive ester of Ampicillin) is resorbed quicker and gives higher concentrations in the nasal secretions. Thus, the therapeutic effect is better in severe cases as compared to Ampicillin. Moreover, the side effects are less.