Bacterial biofilms in patients with chronic rhinosinusitis.

The possible presence of biofilms was examined in mucosal specimens of 15 patients, undergoing functional endoscopic sinus surgery or a modified Caldwell-Luc approach for chronic rhinosinusitis (CRS). Biofilms were found in 7 of the 15 patients, positive cultures being obtained in most samples, which supports the role of biofilms as an important factor in the pathogenesis of CRS.

Experimental studies of vibratory trauma of Corti's organ. II. Scanning electron microscopy.

In the first part of this study, the authors presented the results of cochlear microphonics measurements in guinea pigs subjected to long-term whole-body vibration. In animals undergoing vibration over 30, 90, and 180 days, a statistically significant lowering of voltage over the range up to 2 kHz was seen. In accordance with cochlear-frequency position, this pointed to possible formation of sensory epithelium damages in the fourth and third turning. In the present study an attempt was made to verify electrophysiological measurements with a scanning electron microscope. In all, 80 cochleae were examined, 20 in each group of animals: one control and three experimental groups. The healthy animals showed a correct picture of the sensory epithelium in each case, whereas its damage was ascertained in all the study groups. The damage advanced with a longer duration of the experiment and was most often seen in the outer hair cell region of the apex, where it gradually spread towards the base of the cochlea. The damage of cells decreased from the circumference to the modiolus, and the inner hair cells showed considerably greater resistance to vibration. The results of the study demonstrate the harmful effect of mechanical vibration on the inner ear. According to the observed pattern of damage, one can expect an increasing hearing impairment in the low and medium frequency range in persons exposed to whole-body vibration.

[Experimental laser stapedectomy. Scanning electron microscopy studies]. / Doswiadczalna stapedotomia laserowa. Badania w mikroskopie elektronowym.

The results of experimental tests performed upon 16 human stapes taken from cadavers were presented. The aim of the experiment was to define optimal parameters of laser stapedotomy. The less harmful range of argon laser energy for making the hole 0.6 mm diameter in the stape footplate was determined. There were two zones of tissue damage around the footplate's hole seen in scanning microscope. The internal area was made of carbonized tissue. The osseous tissue of the external zone had cavernous-cystic structure and lamellar stratification.

Cholestyramine as an adsorbent in acute lindane poisoning: a murine model.

STUDY OBJECTIVES: To compare the effectiveness of single-dose cholestyramine versus single-dose activated charcoal in preventing clinical toxicity after acute lindane ingestion. DESIGN: CD-1 mice received lindane by enteral (gavage) and parenteral (intraperitoneal) routes, followed by enteral administration of either cholestyramine (2.25 g/kg) or activated charcoal (2.25 g/kg), with subsequent observation for convulsions and death. MEASUREMENTS: The doses of lindane at which 50% of mice developed convulsions (CD50) and at which 50% of mice died (LD50) were established and compared among control, charcoal-, and cholestyramine-treated groups. RESULTS: For lindane administered by gavage, the differences in the CD50 and LD50 between the control and the activated charcoal groups were not statistically significant. However, a significant difference did exist in both the CD50 and the LD50 between the group receiving cholestyramine and the control group and between the cholestyramine and activated charcoal groups. After IP administration of lindane, the difference in CD50 or LD50 among control, activated charcoal, or cholestyramine groups was not significantly different. CONCLUSION: In the murine model, cholestyramine is more effective than activated charcoal in preventing absorption of lindane, thus preventing convulsions and death. These data support the need for clinical studies to determine whether cholestyramine may be a more effective treatment than activated charcoal for acute lindane ingestions in human beings.

[Effect of Pseudomonas aeruginosa on Trichomonas vaginalis in vitro--electron-microscopic studies]. / Wplyw Pseudomonas aeruginosa na Trichomonas vaginalis in vitro. Badania elektronomikroskopowe.

Interaction between T. vaginalis and P. aeruginosa was studied in vitro. Protozoan cells were incubated in 0.9% NaCl at 37 degrees C for 30 and 150 min. with bacteria, alive or killed by heating for 10 min. at 100 degrees C. Transmission electron microscope observations showed weak ++phagocytic activity (less than 10%) of T. vaginalis against living P. aeruginosa. Phagocytosis of these bacteria caused death of T. vaginalis. Disintegration and autolysis of T. vaginalis resulted probably from action of exotoxin A produced by P. aeruginosa. Phagocytosis of dead P. aeruginosa has not been observed.

Role of various water clusters in IR absorption in the 8-14-microm window region.

A controversy exists over the cause of the IR absorption in the 8-14-microm wavelength window region. One explanation for the continuum absorption is to consider the accumulation of the far wings of strong water monomer absorption lines. On the other hand, other researchers believe that the IR absorption originates from the water dimer complex. Some other researchers claim that either water clusters of larger size or hydrated aerosols are responsible for the continuum absorption. Here we explore the hitherto less-understood systems of water clusters, both homomolecular and heteromolecular, including the water dimer, to enhance our knowledge of the cause of the IR absorption. The present study indicates that homomolecular water clusters larger than the dimer are not responsible for the continuum absorption.

Water cluster interpretation of IR absorption spectra in the 8-14-microm wavelength region.

Recently various investigators have suggested that the anomalous atmospheric absorption spectra in the window wavelength region of 8-14 microm is due to the presence of the water dimer or other water clusters. This suggestion has been made on the grounds that the IR absorptivity has a dependency on the squared value of the partial water vapor pressure or nonlinear vapor pressure and negative temperature dependence, and that the effect of foreign broadening is negligible compared with that of self-broadening. Here we present a theoretical study of the IR continuous absorption by the water dimer in the path containing pure water vapor. In this paper we report our computed results of the intermolecular normal vibrational frequencies, concentrations, and absorption coefficients of the water dimer in the gas phase, focusing our primary attention to the IR absorption in the 8-14-microm wavelength region. Our analysis indicates that the dimer may be an important contributor to the IR absorption in the above mentioned spectral range, and that this region corresponds to the wing of the vibrational transition band associated with an intermolecular librational motion of the water dimer.