[Spontaneous course of traumatic tympanic membrane perforations]

BACKGROUND

Traumatic eardrum perforation is a common presentation in otorhinolaryngologic practices and emergency clinics. A consistent management strategy (active intervention vs. watchful waiting) is, however, still lacking.

OBJECTIVE

In the following study, the outcome of watchful waiting is analyzed and presented.

MATERIALS AND METHODS

A collective of 272 patients presenting at two different specialist ENT practices within days of traumatic tympanic membrane perforation from June 2002 to March 2019 were analyzed. Treatment was non-surgical, with prospective monitoring. Whereas antibiotics were not given at all in one practice, they were given only upon signs of infection in the other practice. The outcome was evaluated retrospectively on the basis of patient files.

RESULTS

The collective consisted of 185 males and 87 females. Mean age was 30 years (range: 7 months to 82 years). The perforations were most commonly located in the upper anterior and lower posterior quadrants. According to Griffin grading, the size was grade I in 97%. The three most common causes were impact to the ear, barotrauma, and foreign bodies. Under a watchful waiting regimen, 95% of the patients presenting for follow-up checks showed complete closure.

CONCLUSION

Watchful waiting can be assessed as appropriate in traumatic eardrum perforation, provided otorhinolaryngologic follow-up is ensured. An exception is blast injury, which is now much less common in Central Europe, as this is associated with a risk of secondary cholesteatomas. In these rare cases, active treatment with surgical exploration of the middle ear including relining the perforation is indicated.

Spin wave diffraction and perfect imaging of a grating

We study the diffraction of Damon-Eshbach-type spin waves incident on a one-dimensional grating realized by microslits in a thin Permalloy film. By means of time-resolved scanning Kerr microscopy, we observe unique diffraction patterns behind the grating which exhibit replications of the spin wave field at the slits. We show that these spin wave images, with details finer than the wavelength of the incident Damon-Eshbach spin wavelength, arise from the strongly anisotropic spin wave dispersion.

Resonant Raman transitions into singlet and triplet states in InGaAs quantum dots containing two electrons

Semiconductor quantum dots containing two electrons, also called artificial quantum-dot helium atoms, are model structures to investigate the most fundamental many-particle states induced by Coulomb interaction and the Pauli exclusion principle. Here, electronic excitations in quantum-dot helium are investigated by resonant Raman spectroscopy in magnetic fields. We observe transitions from the ground state into the excited singlet state and, in the depolarized Raman configuration which allows spin-flip processes, into the triplet state.

Optical microcavities formed by semiconductor microtubes using a bottlelike geometry

We report on the realization of optical microtube resonators with a bottlelike geometry. The measured eigenenergies and the measured axial field distributions of the modes can be described by a straight and intuitive model using an adiabatic separation of the circulating and the axial propagation. The dispersion of the axial mode energies follows a photonic quasi-Schrödinger equation including a quasipotential which can be determined for the actual geometry of the microtube in a precise and simple way. We show that tailoring the geometry of the microtube bottle resonators enables the realization of a wide variety of mode distributions and dispersion relations.

[Air quality in schools - classroom levels of carbon dioxide (CO2), volatile organic compounds (VOC), aldehydes, endotoxins and cat allergen]

Children are assumed to be more vulnerable to health hazards and spend a large part of their time in schools. To assess the exposure situation in this microenvironment, we evaluated the indoor air quality in winter 2004/5 in 92 classrooms, and in 75 classrooms in summer 2005 in south Bavaria, Germany. Indoor air climate parameters (temperature, relative humidity), carbon dioxide (CO2) and various volatile organic compounds, aldehydes and ketones were measured. Additionally, cat allergen (Fel d1) and endotoxin (LAL-test) were analysed in the settled dust of school rooms. Data on room and building characteristics were collected by use of a standardised form. Only data collected during teaching hours were considered in analysis. The median indoor CO2 concentration in the classrooms ranged in the winter and summer period from 598 to 4 172 ppm and 480 to 1 875 ppm, respectively. While during the winter period in 92% of the classrooms the CO2 daily medians went above 1 000 ppm, the percentage of classrooms with increased CO2 concentration fell to 28% in summer. In winter, in 60% of classes the daily median CO2 concentration exceeded 1 500 ppm, while in summer this threshold was reached by only 9%. A high concentration of CO2 was associated with a high number of pupils, a low room surface area and a low room volume. The levels of total volatile organic compounds (TVOC) in classrooms ranged between 110 and 1 000 microg/m3 (median in winter 345 microg/m3, in summer 260 microg/m3). Acetone, formaldehyde and acetaldehyde were measured in concentrations from 14.0 to 911 microg/m3, from 3.1 to 46.1 microg/m3, and from 2.9 to 78 microg/m3, respectively. The other aldehydes were detected in minor amounts only. The median Fel d1 level in winter was 485 ng/g dust (20 to 45 160 ng/g) and in summer it was 417 ng/g (40-7 470 ng/g). We observed no marked differences between the two sampling periods and between smooth floors and rooms with carpeted floors. No differences were found according to room surface area and room volume. The median endotoxin contents in winter and summer were 19.7 EU/mg dust (6.6 to 154 EU/mg) and 32.2 EU/mg (9.6 to 219 EU/mg), respectively. The levels varied significantly between the sampling periods, but were independent of room surface area, room volume and surface floorings. Overall the results of VOC, aldehydes, ketones and endotoxin indicate, in general, a low exposure level in classrooms. The observed concentrations of cat allergens should be considered as a meaningful exposure route and thus could be tackled within preventive programs.

Integrated Exposure Assessment Survey (INES)

The Integrated Exposure Assessment Survey (INES) was started in the year 2005. Altogether 50 healthy adults living in Bavaria, Germany, were included into the study. Monitoring was conducted in accordance with relevant routes of human exposure (inhalation, ingestion) and integrated different pathways (indoor air, food, house dust). This approach consisted of a combination of external measurements of contaminants with the determination of these substances or their metabolites in body fluids. The target substances were phthalates, perfluorinated compounds (PFC), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), and polybrominated diphenylethers (PBDEs). This paper gives a brief description of the objectives and the concept of INES as well as methods of sampling and analyses of target compounds. Some preliminary results of biomonitoring data for PFC and phthalates as well as of the dietary intake of DEHP will be discussed.

Optical modes in semiconductor microtube ring resonators

We demonstrate optical modes in InGaAs/GaAs microtubes acting as optical ring resonators. Self-supporting microtubes were fabricated by optical lithography and wet-etching processes utilizing the self-rolling mechanism of strained bilayers. The optical modes were probed by the photoluminescence of InAs quantum dots embedded in the tube's wall. In this novel microtube ring resonator we find a spectrum of sharp modes. They are in very good agreement with the theoretical results for a closed thin dielectric waveguide.

Quantized dispersion of two-dimensional magnetoplasmons detected by photoconductivity spectroscopy

We find that the long-wavelength magnetoplasmon, resistively detected by photoconductivity spectroscopy in high-mobility two-dimensional electron systems, deviates from its well-known semiclassical nature as uncovered in conventional absorption experiments. A clear filling-factor dependent plateau-type dispersion is observed that reveals a so far unknown relation between the magnetoplasmon and the quantum Hall effect.

Spectroscopy of few-electron collective excitations in charge-tunable artificial atoms

We report the investigation of electronic excitations in InGaAs self-assembled quantum dots using resonant inelastic light scattering. The dots can be charged via a gate by N=1, em leader,6 electrons. We observe excitations, which are identified as transitions of electrons, predominantly from the s to the p shell (s-p transitions) of the quasiatoms. We find that the s-p transition energy decreases and the observed band broadens, when the p shell is filled with 1 to 4 electrons. By a theoretical model, which takes into account the full Coulomb interaction in the few-electron artificial atom, we can confirm the experimental results to be an effect of the Coulomb interaction in the quantum dot.

Optical probing of a fractionally charged quasihole in an incompressible liquid

In photoluminescence spectroscopy of a low-mobility two-dimensional electron gas subjected to a quantizing magnetic field, we observe an anomaly around nu=1 / 3 at a very low temperature (0.1 K) and an intermediate electron density (0.9 x 10(11) cm(-2)). The anomaly is explained as due to perturbation of the incompressible liquid at the Laughlin state due to close proximity of a localized charged exciton which creates a fractionally charged quasihole in the liquid. The anomaly of approximately 2 meV can be destroyed by applying a small thermal energy of approximately 0.2 meV that is enough to close the quasihole energy gap.

Relation between peri-operative antithrombin activity and deep vein thrombosis after elective hip replacement surgery

BACKGROUND

The purpose of the study was to evaluate whether the postoperative depletion or the preoperative antithrombin (AT) activity is related to the occurrence of deep vein thrombosis (DVT) in patients receiving low-molecular-weight heparin for DVT prevention after elective hip replacement surgery.

PATIENTS AND METHODS

In 93 patients AT-activity and standard laboratory parameter were determined on the preoperative day and daily for one week after operation. Furthermore, a color-coded compression sonography was performed before and 8-10 days after surgery. The amount of blood loss and blood transfusions was evaluated. Patients were divided into two groups in respect to the occurrence of a postoperative DVT.

RESULTS

The overall incidence of DVT was 8.6% (n = 8). Patients with DVT had a significantly lower preoperative AT-activity (80.6 +/- 3.31%) compared to those without DVT (98.1 +/- 1.12%, p < 0.001), however, without being predictive for DVT (positive predictive value 0.71). There was no association between postoperative fall of AT, the lowest postoperative AT activity, blood loss or blood substitution and DVT.

CONCLUSIONS

It has to be expected that a small fraction of patients for elective hip surgery present with AT-activity levels possibly being insufficient for a therapeutic effect of low-molecular-weight heparin even preoperatively. Those patients are subject to a significant higher risk of DVT postoperatively.

[Recurrent luxations after arthroscopic refixation of the labrum using suture anchors in traumatic ventral shoulder luxation]

OBJECTIVE

Recurrence rates after arthroscopic labral reconstruction for anterior shoulder instability are still higher than after open procedures. Therefore, proper selection of patients becomes increasingly important. The aim of this study was to investigate factors influencing recurrence rates after arthroscopic labral repair with suture anchors.

PATIENTS AND METHODS

We examined 53 patients (43 male, 10 female) with traumatic anterior shoulder dislocations, who were treated with arthroscopic labral repair using Fastak-Suture anchors between 1995 and 1996. The average follow-up time was 18 (12-30) months. The mean age of the patients at the time of operation was 27 (15-44) years.

RESULTS

Postoperatively, 11 patients (20.7%) reported on redislocations. Recurrence rates increased significantly in patients with more than 4 preoperative dislocations and in patients with bony Bankart lesions. In patients without redislocations, the mean Rowe score improved from 65.9 (SD +/- 12.3) preoperatively to 88.6 (SD +/- 12.5) at follow-up. Thus, there were 24 excellent, 9 good and 6 fair results, while in 3 patients with persisting signs of shoulder instability results had to be estimated as poor. Deficits in the range of motion of more than 15 degrees were seen in 7 patients with predominant affection of the external rotation.

CONCLUSION

Frequent preoperative dislocations and bony Bankart lesions contribute substantially to high recurrence rates after arthroscopic labral repair. Therefore, in these cases open procedures should be preferred.

Application of a purge and trap TDS-GC/MS procedure for the determination of emissions from flame retarded polymers

Emissions of volatile organic compounds (VOCs) from different thermoplastic polymers used in electrotechnical applications were investigated using a purge and trap procedure that involved adsorption on Tenax GR. Results were compared to those for an operating TV set monitored in a test chamber. The analyses were in both cases carried out using thermodesorption gas chromatography with mass spectrometric detection (TDS-GC/MS). Substances identified were monomers, volatile additives, or related compounds. Special attention was given to the detection of halogenated compounds. Their origin was studied using reference samples and synthetic standards.

Isolation and structural characterization of glycosphingolipids of in vitro propagated human umbilical vein endothelial cells

To investigate in detail the expression of glycosphingolipids (GSLs) on endothelial cells, 4.85 x 10(9) human umbilical vein endothelial cells (HUVECs) were cultivated in a 2 l bioreactor using microcarriers as a support for anchorage dependent growing cells. Neutral GSLs and gangliosides were isolated and their structures were determined by TLC immunostaining, fast atom bombardment-mass spectrometry (FAB-MS) of the native GSLs, and gas chromatography-electron impact mass spectrometry (GC-EIMS) of partially methylated alditol acetates. GbOse4Cer, GbOse3Cer, and LacCer, all carrying mainly C24- and C16-fatty acid beside C18-sphingosine, were detected as the major neutral GSLs (36%, 23%, and 15% of the total orcinol stain, respectively); GlcCer, nLcOse4Cer, and nLcOse6Cer were expressed to substantial minor amounts (9%, 12%, and 5% of the total orcinol stain, respectively). TLC immunostaining revealed the presence of lipid bound Lewisx antigen, whereas the isomeric Lewisa structure was detectable only in very low quantities. GM3(Neu5Ac) with C18-sphingosine was the major ganglioside constituting about 90% of the whole ganglioside fraction. The fatty acid composition was determined by GC-MS of fatty acid methyl esters, indicating the predominance of C24- and C16-substituted GM3(Neu5Ac), followed by C18- and C22-substituted species. Terminally alpha2-3 sialylated neolacto-series ganglioside IV3Neu5Ac-nLcOse4Cer was the second most abundant ganglioside in HUVECs (8% of the total resorcinol stain), and IV6Neu5Ac-nLcOse4Cer and VI3Neu5Ac-nLcOse6Cer (together less than 2% of total resorcinol stain) were found in minor quantities. Lipid bound sialyl Lewisx antigen with poly-N-acetyllactosaminyl chains, and traces of gangliotetraose-type gangliosides GM1 and GD1a were identified by TLC immunostaining. The expression of dominant neutral GSLs LacCer, GbOse3Cer, and GbOse4Cer, and of ganglioside GM3(Neu5Ac) was assayed by indirect immunofluorescence microscopy of cell layers grown in chamber slides, each showing different plasma membrane and subcellular distribution patterns. The complete structural characterization of GSLs from HUVECs contributes to our understanding about their functional role, not only of the carbohydrate but also of the lipid moiety, as receptors for bacterial toxins, as cell surface antigens of cellular interaction and as receptors for blood components and macromolecules of the extracellular matrix.

[Changes in proprioceptive capacities of the shoulder joint in ventral shoulder instability. A comparative study before and after arthroscopic labrum refixation]

Measurements of movement sense determined by threshold levels for the perception of motion of the shoulder were performed in 10 patients with unilateral posttraumatic shoulder instabilities, in 30 patients who underwent arthroscopic labrum repair for recurrent anterior shoulder instability, and in 15 age-related controls. In patients with anterior shoulder instabilities threshold levels for the perception of motion were higher. In addition, movement sense measurements revealed a marked, but time dependent improve of proprioceptive abilities in patients who underwent arthroscopic labrum repair. While in the shoulders of patients with an postoperative period shorter than 18 months elevated threshold levels for the perception of motion still could be observed, after a postoperative period of 18 moths or more movement sense was not different from normal, uninjured shoulders. In conclusion, our study gives evidence for a proprioceptive deficit with anterior shoulder instability which improves significantly after arthroscopic labrum repair. The restitution of proprioceptive abilities, however, seems to be a time dependent process.

Large scale purification of gangliosides GM3(Neu5Ac) and GM3(Neu5Gc) by trimethylaminoethyl-Fractogel high-performance liquid chromatography

A preparative anion-exchange high-performance liquid chromatographic method for the separation of the closely allied monosialogangliosides GM3(Neu5Ac) and GM3(Neu5Gc) has been developed. Hybridoma cells, readily available material derived from industrial monoclonal antibody production, were used as ganglioside source and led to fractions with pure GM3(Neu5Ac) and GM3(Neu5Gc) in high milligram quantities. The crude ganglioside extract was loaded onto columns filled with the strong anion-exchanger trimethylaminoethyl (TMAE)-Fractogel. Gangliosides were eluted from the stationary phase with a gradient system of ammonium acetate in methanol. The scaled-up approach ranged over more than one order of magnitude from 20 to 500 mg batches of GM3 gangliosides. Thus, the high-resolution power of the strong anion-exchanger TMAE-Fractogel allowed the preparative isolation by one-step column chromatography of two GM3 specimens which only differ in one hydroxyl group at position 5 of the neuraminic acid (N-acetyl-versus N-glycolylneuraminic acid).

Replacement of chloroform throughout glycosphingolipid isolation

Chloroform, the predominant constituent of solvents used for lipid extraction and chromatography, is believed to give rise to birth defects and serious damage to health, and may also be carcinogenic. Therefore, simple and successful methods have been developed to replace chloroform throughout the isolation of glycosphingolipids (GSLs) by less harmful solvents. Gangliosides of sheep brain (ganglio-series gangliosides GM1, GDla, GD1b and GT1b) and of lymphocyte-derived mouse hybridoma cells (namely GM3) were extracted with six different solvent mixtures. Chloroform:methanol:water (40:80:30, v/v/v) was employed as reference (solvent I). Combinations without chloroform were: n-propanol:water (40:10, v/v) (II), methylisobutylketone:methanol:water (40:80:30, v/v/v) (III), ethylacetate:methanol:water (40:72:28, v/v/v) (IV), methylacetate:methanol:water (40:72:28, v/v/v) (V) and petroleum ether:isopropanol:water (40:112:38, v/v/v) (VI). After extraction and dialysis, the weight of lipid extract as well as the content of sialic acid, gangliosides, sulphatides and phospholipids were determined. Quantitation of GSL yields in crude extracts obtained by the alternative solvent mixtures II to VI showed recoveries of brain gangliosides from nearly 67% up to 104% compared with the reference solvent I. Extraction of hybridoma cells by means of the alternative combinations without chloroform revealed at least the same and mostly better ganglioside yields in the range from 98% to 116% with regard to the reference solvent I. n-Propanol:water (II) and methylisobutylketone:methanol:water (III) were the recommended extractants for both tissues. Therefore, the methods described offer simple, less hazardous and successful strategies for GSL extraction in excellent yield without the need for using chloroform.

Different binding capacities of influenza A and Sendai viruses to gangliosides from human granulocytes

The structures of gangliosides from human granulocytes were elucidated by fast atom bombardment mass spectrometry and by gas chromatography/mass spectrometry as their partially methylated alditol acetates. In human granulocytes besides GM3 (II3Neu5Ac-LacCer), neolacto-series gangliosides (IV3Neu5Ac-nLcOse4Cer, IV6Neu5Ac-nLcOse4Cer and VI3Neu5Ac-nLcOse6Cer) containing C24:1, and to some extent C22:0; and C16:0 fatty acid in their respective ceramide portions, were identified as major components. In this study we demonstrate that gangliosides from human granulocytes, the second most abundant cells in peripheral blood, can serve as receptors for influenza viruses A/PR/8/34 (H1N1), A/X-31 (H3N2), and a parainfluenza virus Sendai virus (HNF1, Z-strain). Viruses were found to exhibit specific adhesion to terminal Neu5Ac alpha 2-3Gal and/or Neu5Ac alpha 2-6Gal sequences as well as depending on the chain length of ganglioside carbohydrate backbones from human granulocytes, these important effector cells which represent the first line of defence in immunologically mediated reactions.

Frequency and conditions of spontaneous plasmid transfer from E. coli to cultured mammalian cells

After exposing mammalian cell cultures to E. coli carrying the complete cDNA of poliovirus 1 in a plasmid, formation of polioviruses ensued even when no eukaryotic transcription signals were contained in the plasmid. The age of the bacteria greatly influenced the frequency of gene transfer, which was low if the bacteria were harvested in the exponential stage, reaching a maximum at the stationary phase and declining afterwards. Since the gene transfer was inhibited by cytochalasin B, phagocytosis of the bacteria could be a first step for the transfer; however, other mechanisms could not be ruled out.

Nondestructive detection of gangliosides with lipophilic fluorochromes and their employment for preparative high-performance thin-layer chromatography

A simple and effective procedure for the isolation and purification of gangliosides by preparative thin-layer chromatography is described. The method is based on nondestructive visualization of gangliosides on silica gel-precoated thin-layer chromatography plates by staining with uncharged lipophilic fluorochromes. Fluorescent dyes were added in low concentrations into the mobile phase (0.002%, w/v) without any interference of the ganglioside separation. After uv localization, the fluorescent zones were scraped off the plate and the silica gel was extracted with chloroform/methanol/water (30/60/8). In the following step fluorochromes were removed from gangliosides containing crude extracts by anion-exchange chromatography on DEAE-Sepharose. After desalting, impurities were removed by Iatrobeads chromatography. The method described offers an easy to handle and successful preparative thin-layer chromatography strategy to obtain pure gangliosides in microgram and miligram quantities.