Primary hepatic metastatic epitheloid trophoblastic tumor of the uterus treated with multimodal therapy including pembrolizumab and thermoablation. Case report of an extremely rare disease and review of the literature

Epithelioid trophoblastic tumor (ETT) is a rare gestational trophoblastic tumor, first described by Shih and Kurman in 1998. ETT often present as abnormal vaginal bleeding in women of reproductive age, but unlike more common forms of GTN tend to produce much less human chorionic gonadotropin (hCG) for the volume of disease present. ETT can occur after any gestational event and can occur in both intrauterine and extrauterine sites. We present a case of a 46-year-old female patient incidentally diagnosed with ETT and hepatic metastasis. Therapy was multimodal and involved chemotherapy, operation, thermoablation of liver metastases and immunocheckpoint inhibitor. The patient remains disease free for almost four years now. ETT presents a diagnostic challenge due to their rarity and histologic resemblance to other pathologies. ETT can be relatively chemo resistant and are therefore often treated surgically. Misdiagnosis might delay effective treatment and affects survival.

Climate-driven spatial and temporal patterns in peatland pool biogeochemistry

Peatland pools are freshwater bodies that are highly dynamic aquatic ecosystems because of their small size and their development in organic-rich sediments. However, our ability to understand and predict their contribution to both local and global biogeochemical cycles under rapidly occurring environmental change is limited because the spatiotemporal drivers of their biogeochemical patterns and processes are poorly understood. We used (1) pool biogeochemical data from 20 peatlands in eastern Canada, the United Kingdom, and southern Patagonia and (2) multi-year data from an undisturbed peatland of eastern Canada, to determine how climate and terrain features drive the production, delivering and processing of carbon (C), nitrogen (N), and phosphorus (P) in peatland pools. Across sites, climate (24%) and terrain (13%) explained distinct portions of the variation in pool biogeochemistry, with climate driving spatial differences in pool dissolved organic C (DOC) concentration and aromaticity. Within the multi-year dataset, DOC, carbon dioxide (CO2 ), total N concentrations, and DOC aromaticity were highest in the shallowest pools and at the end of the growing seasons, and increased gradually from 2016 to 2021 in relation to a combination of increases in summer precipitation, mean air temperature for the previous fall, and number of extreme summer heat days. Given the contrasting effects of terrain and climate, broad-scale terrain characteristics may offer a baseline for the prediction of small-scale pool biogeochemistry, while broad-scale climate gradients and relatively small year-to-year variations in local climate induce a noticeable response in pool biogeochemistry. These findings emphasize the reactivity of peatland pools to both local and global environmental change and highlight their potential to act as widely distributed climate sentinels within historically relatively stable peatland ecosystems.

Carbon uptake in Eurasian boreal forests dominates the high-latitude net ecosystem carbon budget

Arctic-boreal landscapes are experiencing profound warming, along with changes in ecosystem moisture status and disturbance from fire. This region is of global importance in terms of carbon feedbacks to climate, yet the sign (sink or source) and magnitude of the Arctic-boreal carbon budget within recent years remains highly uncertain. Here, we provide new estimates of recent (2003-2015) vegetation gross primary productivity (GPP), ecosystem respiration (R_eco ), net ecosystem CO₂ exchange (NEE; R_eco  - GPP), and terrestrial methane (CH₄ ) emissions for the Arctic-boreal zone using a satellite data-driven process-model for northern ecosystems (TCFM-Arctic), calibrated and evaluated using measurements from >60 tower eddy covariance (EC) sites. We used TCFM-Arctic to obtain daily 1-km² flux estimates and annual carbon budgets for the pan-Arctic-boreal region. Across the domain, the model indicated an overall average NEE sink of -850 Tg CO₂ -C year^-1 . Eurasian boreal zones, especially those in Siberia, contributed to a majority of the net sink. In contrast, the tundra biome was relatively carbon neutral (ranging from small sink to source). Regional CH₄ emissions from tundra and boreal wetlands (not accounting for aquatic CH₄ ) were estimated at 35 Tg CH₄ -C year^-1 . Accounting for additional emissions from open water aquatic bodies and from fire, using available estimates from the literature, reduced the total regional NEE sink by 21% and shifted many far northern tundra landscapes, and some boreal forests, to a net carbon source. This assessment, based on in situ observations and models, improves our understanding of the high-latitude carbon status and also indicates a continued need for integrated site-to-regional assessments to monitor the vulnerability of these ecosystems to climate change.

Skeletal injuries after cesarean section - a rare differential diagnosis of child abuse

Birth-related fractures are an important differential diagnosis of child abuse in early infancy. While fractures associated to vaginal deliveries are well known, cesarean section is not necessarily known to cause such injuries. Nevertheless neonatal fractures have been described after cesarean sections. To give an overview over the frequency and typical locations of such fractures, the appearance of symptoms and the timespan until diagnosis, a literature research was conducted via Google scholar and Pubmed, using the key words "cesarean section" and "fractures". Birth-related fractures after cesarean sections are rare but can occur, with the long bones being particularly affected. Therefore, birth injuries should always be considered in the forensic medical assessment of fractures in early infancy, even after cesarean section. To enable a differentiation between birth trauma and physical abuse, birth and operation records should be checked for surgical manoeuvres, possible difficulties during the procedure or other risk factors. Birth-related fractures are usually detected early; in rare cases, the diagnosis is made only weeks after birth.

Substantial hysteresis in emergent temperature sensitivity of global wetland CH4 emissions

Wetland methane (CH4) emissions ([Formula: see text]) are important in global carbon budgets and climate change assessments. Currently, [Formula: see text] projections rely on prescribed static temperature sensitivity that varies among biogeochemical models. Meta-analyses have proposed a consistent [Formula: see text] temperature dependence across spatial scales for use in models; however, site-level studies demonstrate that [Formula: see text] are often controlled by factors beyond temperature. Here, we evaluate the relationship between [Formula: see text] and temperature using observations from the FLUXNET-CH4 database. Measurements collected across the globe show substantial seasonal hysteresis between [Formula: see text] and temperature, suggesting larger [Formula: see text] sensitivity to temperature later in the frost-free season (about 77% of site-years). Results derived from a machine-learning model and several regression models highlight the importance of representing the large spatial and temporal variability within site-years and ecosystem types. Mechanistic advancements in biogeochemical model parameterization and detailed measurements in factors modulating CH4 production are thus needed to improve global CH4 budget assessments.

Increased high-latitude photosynthetic carbon gain offset by respiration carbon loss during an anomalous warm winter to spring transition

Arctic and boreal ecosystems play an important role in the global carbon (C) budget, and whether they act as a future net C sink or source depends on climate and environmental change. Here, we used complementary in situ measurements, model simulations, and satellite observations to investigate the net carbon dioxide (CO₂ ) seasonal cycle and its climatic and environmental controls across Alaska and northwestern Canada during the anomalously warm winter to spring conditions of 2015 and 2016 (relative to 2010-2014). In the warm spring, we found that photosynthesis was enhanced more than respiration, leading to greater CO₂ uptake. However, photosynthetic enhancement from spring warming was partially offset by greater ecosystem respiration during the preceding anomalously warm winter, resulting in nearly neutral effects on the annual net CO₂ balance. Eddy covariance CO₂ flux measurements showed that air temperature has a primary influence on net CO₂ exchange in winter and spring, while soil moisture has a primary control on net CO₂ exchange in the fall. The net CO₂ exchange was generally more moisture limited in the boreal region than in the Arctic tundra. Our analysis indicates complex seasonal interactions of underlying C cycle processes in response to changing climate and hydrology that may not manifest in changes in net annual CO₂ exchange. Therefore, a better understanding of the seasonal response of C cycle processes may provide important insights for predicting future carbon-climate feedbacks and their consequences on atmospheric CO₂ dynamics in the northern high latitudes.

Large loss of CO2 in winter observed across the northern permafrost region

Recent warming in the Arctic, which has been amplified during the winter^1-3, greatly enhances microbial decomposition of soil organic matter and subsequent release of carbon dioxide (CO₂)⁴. However, the amount of CO₂ released in winter is highly uncertain and has not been well represented by ecosystem models or by empirically-based estimates^5,6. Here we synthesize regional in situ observations of CO₂ flux from arctic and boreal soils to assess current and future winter carbon losses from the northern permafrost domain. We estimate a contemporary loss of 1662 Tg C yr^-1 from the permafrost region during the winter season (October through April). This loss is greater than the average growing season carbon uptake for this region estimated from process models (-1032 Tg C yr^-1). Extending model predictions to warmer conditions in 2100 indicates that winter CO₂ emissions will increase 17% under a moderate mitigation scenario-Representative Concentration Pathway (RCP) 4.5-and 41% under business-as-usual emissions scenario-RCP 8.5. Our results provide a new baseline for winter CO₂ emissions from northern terrestrial regions and indicate that enhanced soil CO₂ loss due to winter warming may offset growing season carbon uptake under future climatic conditions.

Direct and indirect climate change effects on carbon dioxide fluxes in a thawing boreal forest-wetland landscape

In the sporadic permafrost zone of northwestern Canada, boreal forest carbon dioxide (CO₂ ) fluxes will be altered directly by climate change through changing meteorological forcing and indirectly through changes in landscape functioning associated with thaw-induced collapse-scar bog ('wetland') expansion. However, their combined effect on landscape-scale net ecosystem CO₂ exchange (NEE_LAND ), resulting from changing gross primary productivity (GPP) and ecosystem respiration (ER), remains unknown. Here, we quantify indirect land cover change impacts on NEE_LAND and direct climate change impacts on modeled temperature- and light-limited NEE_LAND of a boreal forest-wetland landscape. Using nested eddy covariance flux towers, we find both GPP and ER to be larger at the landscape compared to the wetland level. However, annual NEE_LAND (-20 g C m^-2 ) and wetland NEE (-24 g C m^-2 ) were similar, suggesting negligible wetland expansion effects on NEE_LAND . In contrast, we find non-negligible direct climate change impacts when modeling NEE_LAND using projected air temperature and incoming shortwave radiation. At the end of the 21st century, modeled GPP mainly increases in spring and fall due to reduced temperature limitation, but becomes more frequently light-limited in fall. In a warmer climate, ER increases year-round in the absence of moisture stress resulting in net CO₂ uptake increases in the shoulder seasons and decreases during the summer. Annually, landscape net CO₂ uptake is projected to decline by 25 ± 14 g C m^-2 for a moderate and 103 ± 38 g C m^-2 for a high warming scenario, potentially reversing recently observed positive net CO₂ uptake trends across the boreal biome. Thus, even without moisture stress, net CO₂ uptake of boreal forest-wetland landscapes may decline, and ultimately, these landscapes may turn into net CO₂ sources under continued anthropogenic CO₂ emissions. We conclude that NEE_LAND changes are more likely to be driven by direct climate change rather than by indirect land cover change impacts.

The positive net radiative greenhouse gas forcing of increasing methane emissions from a thawing boreal forest-wetland landscape

At the southern margin of permafrost in North America, climate change causes widespread permafrost thaw. In boreal lowlands, thawing forested permafrost peat plateaus ('forest') lead to expansion of permafrost-free wetlands ('wetland'). Expanding wetland area with saturated and warmer organic soils is expected to increase landscape methane (CH₄ ) emissions. Here, we quantify the thaw-induced increase in CH₄ emissions for a boreal forest-wetland landscape in the southern Taiga Plains, Canada, and evaluate its impact on net radiative forcing relative to potential long-term net carbon dioxide (CO₂ ) exchange. Using nested wetland and landscape eddy covariance net CH₄ flux measurements in combination with flux footprint modeling, we find that landscape CH₄ emissions increase with increasing wetland-to-forest ratio. Landscape CH₄ emissions are most sensitive to this ratio during peak emission periods, when wetland soils are up to 10 °C warmer than forest soils. The cumulative growing season (May-October) wetland CH₄ emission of ~13 g CH₄  m^-2 is the dominating contribution to the landscape CH₄ emission of ~7 g CH₄  m^-2 . In contrast, forest contributions to landscape CH₄ emissions appear to be negligible. The rapid wetland expansion of 0.26 ± 0.05% yr^-1 in this region causes an estimated growing season increase of 0.034 ± 0.007 g CH₄  m^-2  yr^-1 in landscape CH₄ emissions. A long-term net CO₂ uptake of >200 g CO₂  m^-2  yr^-1 is required to offset the positive radiative forcing of increasing CH₄ emissions until the end of the 21st century as indicated by an atmospheric CH₄ and CO₂ concentration model. However, long-term apparent carbon accumulation rates in similar boreal forest-wetland landscapes and eddy covariance landscape net CO₂ flux measurements suggest a long-term net CO₂ uptake between 49 and 157 g CO₂  m^-2  yr^-1 . Thus, thaw-induced CH₄ emission increases likely exert a positive net radiative greenhouse gas forcing through the 21st century.

Regional atmospheric cooling and wetting effect of permafrost thaw-induced boreal forest loss

In the sporadic permafrost zone of North America, thaw-induced boreal forest loss is leading to permafrost-free wetland expansion. These land cover changes alter landscape-scale surface properties with potentially large, however, still unknown impacts on regional climates. In this study, we combine nested eddy covariance flux tower measurements with satellite remote sensing to characterize the impacts of boreal forest loss on albedo, eco-physiological and aerodynamic surface properties, and turbulent energy fluxes of a lowland boreal forest region in the Northwest Territories, Canada. Planetary boundary layer modelling is used to estimate the potential forest loss impact on regional air temperature and atmospheric moisture. We show that thaw-induced conversion of forests to wetlands increases albedo: and bulk surface conductance for water vapour and decreases aerodynamic surface temperature. At the same time, heat transfer efficiency is reduced. These shifts in land surface properties increase latent at the expense of sensible heat fluxes, thus, drastically reducing Bowen ratios. Due to the lower albedo of forests and their masking effect of highly reflective snow, available energy is lower in wetlands, especially in late winter. Modelling results demonstrate that a conversion of a present-day boreal forest-wetland to a hypothetical homogeneous wetland landscape could induce a near-surface cooling effect on regional air temperatures of up to 3-4 °C in late winter and 1-2 °C in summer. An atmospheric wetting effect in summer is indicated by a maximum increase in water vapour mixing ratios of 2 mmol mol^-1 . At the same time, maximum boundary layer heights are reduced by about a third of the original height. In fall, simulated air temperature and atmospheric moisture between the two scenarios do not differ. Therefore, permafrost thaw-induced boreal forest loss may modify regional precipitation patterns and slow down regional warming trends.

Preliminary investigations of magnetic modulated nanoparticles for microwave breast cancer detection

This paper investigates the potential of magnetic modulated iron oxide nanoparticles in terms of a contrast enhancement for Ultra-wideband (UWB) breast imaging. The work is motivated by the low dielectric contrast between tumor and normal glandular/fibroconnective tissue. The influence of an external polarizing magnetic field on pure and coated magnetite nanoparticles is investigated in this contribution. Measurements were conducted using M-sequence UWB technology and an oil-gelatin phantom. It is shown that a coating, which is necessary for clinical use, results in a lower signal response, and thus leads to a lower detectability of magnetic modulated nanoparticles.

[Endonasal dacryocystorhinostomies with transillumination and intubation in patients with combined pathologies of the nose and after revision]

BACKGROUND

The results of endonasal dacryocystorhinostomies (DCR) with transillumination and intubation are presented.

MATERIALS AND METHODS

In the period from 1999 to 2009 follow-up examinations of 50 endonasal DCRs were carried out. All patients over 18 were included. The files were systematically evaluated. The follow-up examinations were performed after a minimum of 6 months with anamnesis of epiphora.

RESULTS

50 endonasal DCRs were performed on 40 patients. Initial surgery was performed on 27 lacrimal ducts, 16 patients had already had operations. Corrective surgery was required in 8 cases (7 endonasal DCRs, 1 external DCRs). 78 % women and 22 % men were included. The median age at the time of operation was 48 years; the median duration of preoperative symptoms was 24 months. In 42 % of the cases a chronic dacryocystitis was found. Pre-existing conditions were sarcoidosis in three cases and one case of Wegener's granulomatosis. As well as lacrimal duct obstruction, additional pathologies were treated in the same session [septoplasty (n = 12), sinus operations (n = 10), and cauterisation of the nasal concha (n = 7), removal of a dacryocele (n = 1), conchectomy (n = 1)]. 20 operations were performed on the right side, 26 on the left side and two bilateral. The median duration of the operation was 51 minutes. No operative complications were encountered. The length of stay in hospital was on average four days. The median of follow-up was 23 months. The success rate was 78 %.

DISCUSSION

The success rate of endonasal DCRs is about 70 to 95 %. Thus, the achieved rate in this study is acceptable, especially as 16 of 40 patients underwent revision surgery. Probably this is attributed to the technique of transillumination. The safe intraoperative localisation of the lacrimal sac with a light probe seems to have a positive effect on the removal of obstructions.

[Intraductal application of Levovist® in salivary glands of animals]

BACKGROUND

Several methods are well established for the imaging of salivary glands. Excluding the invasive method sialendoscopy all other methods show the salivary duct system inadequately. The aim of this study is to demonstrate a method to visualize the salivary duct system by B-mode ultrasound.

MATERIAL AND METHODS

In 10 parotid glands of common pig cadavers the ultrasound contrast agent Levovist (®), which is galactose stabilized by palmitic acid was applied into the main salivary ducts while simultaneously performing a transcutaneous B-mode ultrasound.

RESULTS

In all cadavers a visualization of the salivary duct system could be achieved by the application of Levovist (®) because of contrast enhancement. This effect arises as a result of an increased reflection of ultrasound waves on the surface of the microbubbles contained in the contrast agent.

CONCLUSION

A reproducible visualization of the salivary duct system with B-mode ultrasound is possible by an intraductal application of an ultrasound contrast agent. In future this could be established as a reliable and fast method for imaging of the salivary ducts without ionizing radiation for the patient.

Error analysis for determination of accuracy of an ultrasound navigation system for head and neck surgery

OBJECTIVE

The use of conventional CT- or MRI-based navigation systems for head and neck surgery is unsatisfactory due to tissue shift. Moreover, changes occurring during surgical procedures cannot be visualized. To overcome these drawbacks, we developed a novel ultrasound-guided navigation system for head and neck surgery. A comprehensive error analysis was undertaken to determine the accuracy of this new system.

MATERIALS AND METHODS

The evaluation of the system accuracy was essentially based on the method of error definition for well-established fiducial marker registration methods (point-pair matching) as used in, for example, CT- or MRI-based navigation. This method was modified in accordance with the specific requirements of ultrasound-guided navigation. The Fiducial Localization Error (FLE), Fiducial Registration Error (FRE) and Target Registration Error (TRE) were determined.

RESULTS

In our navigation system, the real error (the TRE actually measured) did not exceed a volume of 1.58 mm(3) with a probability of 0.9. A mean value of 0.8 mm (standard deviation: 0.25 mm) was found for the FRE. The quality of the coordinate tracking system (Polaris localizer) could be defined with an FLE of 0.4 +/- 0.11 mm (mean +/- standard deviation). The quality of the coordinates of the crosshairs of the phantom was determined with a deviation of 0.5 mm (standard deviation: 0.07 mm).

CONCLUSION

The results demonstrate that our newly developed ultrasound-guided navigation system shows only very small system deviations and therefore provides very accurate data for practical applications.

Navigation-supported and sonographically-controlled fine-needle puncture in soft tissues of the neck

In surgery, sonography has been a well-accepted means of orientation for years. The immediate vicinity of many vital structures in the head and neck region calls for a very exact visualization of the surgical instrument in the 2-D ultrasonic picture. We report on the development of a new method for navigation-supported and sonographically-controlled fine-needle puncture in soft tissues of the neck. Our system comprises a navigated ultrasound probe, a navigated fine-puncture needle and a coordinate sensor. A personal computer with specially-developed software assists calibration and surgical application. The applicability test for the system is described. In vitro, a model lymph node of 9 mm in diameter had been hit. It is shown that the target structure can be aimed at very precisely by the navigated puncture needle. An accuracy of 97% and a specificity of 99% could be demonstrated. The development of a very precise and easy-to-handle method for navigation-supported fine-needle puncture in the neck region is presented. The outstanding advantage of this method is that no rigid reference gadget fixed to the patient's body is necessary. That makes this method very suitable for surgery in the neck region. Contrary to other sonographically-supported navigation methods in the head and neck region, preoperative imaging (CT or MRT) is dispensable.

[Navigation-assisted sonography for soft tissues in the head and neck region]

BACKGROUND

In soft tissue surgery of the head and neck region tissue shifts limit the usefulness of conventional CT/MRI-based navigation procedures. Furthermore, changes caused by invasive measures cannot be visualized.

METHODS

A novel navigation device for sonography of soft tissues was developed. This consists of a navigated ultrasound scanner, a navigated surgical instrument, and a personal computer with custom-made software. Its use makes an additional visualization by means of CT or MRI dispensable.

RESULTS

The system deviation (three-dimensional error) of this newly developed prototype was less than 1 mm. The practical application in a model setup showed good handling properties of the system. Orientation and approach of the surgical instrument to the sonographically visualized target structure were rapid and accurate.

CONCLUSION

This new navigation system does not require additional CT or MRI images. The navigated ultrasound probe shows tissue changes in real time. This navigation system is especially suitable for invasive procedures in soft tissues.

[Quality management: reduced waiting time and enhanced efficiency in a university ear, nose, and throat outpatient department]

BACKGROUND

The introduction of Diagnosis-Related Groups, which standardize payment for each clinical service, entails keeping the inpatient treatment as short as possible. Thus outpatient treatment is gaining in importance. To cope with this change, organizational and structural modifications of clinic routine are necessary.

METHODS

In the ear, nose, and throat outpatient clinic of Johann Wolfgang Goethe University in Frankfurt, Germany, a hotline was established that allows patients to make appointments and get advice based on quality management guidelines according to DIN EN ISO 9001:2000. The development of this project is described here step by step, from planning to inclusion in the daily clinic routine.

RESULTS

Patient visits became more effective despite increasing demand. This resulted in high satisfaction of patients and clinic personnel alike.

CONCLUSION

This model may contribute considerably to coping with the increasing demand for clinic appointments and to optimal use of a clinic's human resources.

[Quality assessment according to DIN EN ISO 9001:2000: certification in a university ENT department]

BACKGROUND

In 2003, our department inaugurated a quality management system. The certification according to DIN EN ISO 9001:2000 as required by the hospital management was achieved in August 2005. The aims were optimization of internal operating schedules and standardization of procedures according to logistic interfaces with external structures.

METHODS

Since 2000, the implementation of an internal quality management system is required by German law and threatened by penalty in case of non-implementation. Beside a basic audit and optimization of all organizational procedures, all core processes were determined and the approvals checked. These aims involve both the quality of operational procedures, in and outpatient treatment, research, study and teaching and aspects of service such as quickness of scheduling and forwarding of reports as well as economic aspects and efficiency. The department of "quality management", whose main tasks are the professional guidance and the training of the quality management representatives, plays an important role.

RESULTS

Realization of the new regulations and restructuring resulted in an increase in effectiveness and an improvement in operational procedures. In particular, patients and staff have benefited from the reorganized and modified sequence of operations.

CONCLUSION

Implementation of a quality management system in different hospital departments is recommended.

Time-variant parametric estimation of transient quadratic phase couplings between heart rate components in healthy neonates

The heart rate variability (HRV) can be taken as an indicator of the coordination of the cardio-respiratory rhythms. Bispectral analysis using a direct (fast Fourier transform based) and time-invariant approach has shown the occurrence of a quadratic phase coupling (QPC) between a low-frequency (LF: 0.1 Hz) and a high-frequency (HF: 0.4-0.6 Hz) component of the HRV during quiet sleep in healthy neonates. The low-frequency component corresponds to the Mayer-Traube-Hering waves in blood pressure and the high-frequency component to the respiratory sinus arrhythmia (RSA). Time-variant, parametric estimation of the bispectrum provides the possibility of quantifying QPC in the time course. Therefore, the aim of this work was a parametric, time-variant bispectral analysis of the neonatal HRV in the same neonates used in the direct, time-invariant approach. For the first time rhythms in the time course of QPC between the HF component and the LF component could be shown in the neonatal HRV.

[Intraoperative endosonographic guided resection of tongue carcinoma]

BACKGROUND

Exact estimation of a tumor's size and the definition of adequate resection margins in carcinomas of the tongue are often difficult because of the tumor's extension and deep infiltration.

METHODS

We have developed a method that allows intraoperative visualisation and marking of tumor margins. Intra-operative endosonography was performed on nine patients with carcinomas of the tongue using a 8-12 MHz linear array transducer. The oral cavity was flooded with normal saline solution and the transducer was immersed therein. This allowed scanning in a non-contact mode. The tumor margins were marked with a surgical suture under endosonographic monitoring.

RESULTS

In the nine patients studied, the histological margins corresponded to the sonographic margins. The sonographic marking proved to be useful during the resection of the tumor and histological safety margins were respected in each case.

CONCLUSIONS

This non-invasive procedure provides a quick and reliable orientation during the resection of tongue carcinoma, and a more precise and individual definition of resection margins is possible. Intraoperative non-contact use of endosonography is a promising method.

Prognostic impact of EBV-related LMP-1, histologic type, and environmental factors in nasopharyngeal carcinoma in a German population

INTRODUCTION

This retrospective study addressed the possible involvement of latent Epstein-Barr virus (EBV) infection, in particular LMP-1 expression, and further exogenous factors, i.e. tobacco, alcohol and occupational hazardous substances, in nasopharyngeal carcinoma (NPC) in a German population.

PATIENTS AND METHODS

From 1980 to 2000, 44 patients suffering from histologically confirmed NPC were entered into the study. 33 specimens were available for immunostaining (IHC) to analyze LMP-1 expression. Information about environmental exposures were obtained employing a detailed standardized questionnaire.

RESULTS

Outcome of patients with squamous cell NPC (SC-NPC) was significant worse than that of those with non-keratinizing NPC (NK-NPC). Age and tumor size correlated with response to therapy. The group with negative conventional LMP-1 staining showed better overall survival after 5 years compared to the group with positive or marginally positive LMP-1 detection (not significant). Nevertheless, after staining by tyramid-augmented IHC (TSA-IHC), nearly all specimens with negative LMP-1-staining in conventional IHC were found to be clearly positive. All patients with SC-NPC were smokers. The distribution of smokers and non-smokers in the group of NK-NPC was balanced. Comparable to the tobacco observation, there was also a correlation between high alcohol consumption and SC-NPC.

CONCLUSION

Prognosis of NPC is mainly dependent on histologic type. Prognostic impact of LMP-1 is still unclear since LMP-1 was detected in all specimens using TSA-IHC. Therefore, TSA-IHC-LMP-1 detection might be interesting for diagnostic specification and development of new therapeutic strategies in NPC.

On the spatio-temporal organisation of quadratic phase-couplings in ‘tracé alternant’ EEG pattern in full-term newborns

OBJECTIVE

The time courses of quadratic phase-coupling (QPC) of electroencephalographic burst and interburst patterns of the 'trace alternant' (TA) in full-term newborns have been quantified.

METHODS

Using the Gabor expansion, a fast Fourier transformation based method, biamplitude, bicoherence and phase-bicoherence time courses of both burst and interburst patterns have been determined (common average reference EEG recordings). With a frequency resolution of 0.25 Hz and a frequency grid of 1-1.5 <==> 3.5-4.5 Hz (region-of-interest), a number of 15 frequency pairs result. These pairs have been investigated.

RESULTS

The burst and the interburst patterns are characterized by temporally and topographically different QPC profiles. All differences are dominant at the electrode Fp1 followed by Fp2. There is a significant difference (combined multiple and global test strategy) in the QPC characteristics between both patterns within the time period from 0.75 to 1.5 s after the pattern onset at electrode Fp1. The maximal QPC in burst patterns (especially at Fp1) can be observed during this time period. In contrast to this finding, maximal QPC in interburst patterns (at Fp1) are reached immediately after the onset and at 3 s. Summarising all findings, a QPC-rhythm of 0.1 Hz during TA can be assumed.

CONCLUSIONS

It can be assumed that the QPC rhythm of the TA is generated by a pattern-spanning time-variant phase-locking process and there are indications for a possible correspondence between the QPC rhythm and vegetative rhythms.

SIGNIFICANCE

This study showed that advanced, time-variant analysis methods quantifying QPC rhythms are able to add new scientific information to the understanding of nature, characteristics and significance of TA in the neonatal EEG.

Dynamische Magnetresonanztomographie (dMRT)

PURPOSE

With the help of dynamic magnetic resonance tomography (dMRT) the status of tissue microcirculation can be visualized.

METHODS

Dynamic MRI was performed in 13 patients with advanced, nonresectable oro- or hypopharynx carcinoma at the beginning and the end of therapy. Maximal signal intensity and exchange rate constant in the tissue of the tumor and the lymph node metastases were analyzed using a pharmacokinetic two-compartment model.

RESULTS

In all six patients with clinical complete response (CR), the maximal signal intensity increased after therapy in the tissue of the primary tumor and the lymph node metastases. Furthermore, a high decrease in the parameter k(21) was associated with a better prognosis and could be observed especially after combined radiochemotherapy.

CONCLUSION

Our first results indicate that contrast-enhanced dynamic MRI studies before and after radio- or combined radiochemotherapy offer important information about the changes of microcirculation in the tissue of the tumor and lymph node metastases. Furthermore, this information seems to be a promising predictor for clinical outcome of therapy.

[Time variant bispectral analysis based on adaptive recursive Fourier transformation]

An appropriate investigation of quadratic phase couplings (QPC) in non-stationary signals requires time-variant methods of bispectral analysis. A new approach for time-variant estimation of power spectrum and bispectrum based on an adaptively, recursively estimated Fourier transform (ADFT) is presented in this paper. A reduced calculation effort and the possibility of the calculation of the bispectrum for selected frequency triples are important advantages of this method. Because of the recursive calculation, the ADFT is convenient for analysing ongoing signals. This will be demonstrated for simulated and real biomedical signals.

Time-variant non-linear phase-coupling analysis of EEG burst patterns in sedated patients during electroencephalic burst suppression period

OBJECTIVES

The quadratic phase-coupling (QPC) within burst patterns during electroencephalic burst suppression has been quantified.

METHODS

It can be shown that a QPC exists between the frequency ranges 0-2.5 and 3-7.5 Hz and between the frequency ranges 0-2.5 and 8-12 Hz. By means of time-variant bicoherence analysis, a strong phase-locking between the modulating and the modulated component can be identified. The phase-locking is demonstrable within the first 250 ms after the burst onset and comes up to the maximum between 750 and 1250 ms.

RESULTS

The effect is maintained over the whole first part of the burst (2 s) with a decreasing tendency after 1250 ms. All these effects cannot be found in the EEG before entering the burst suppression period (BSP). The transient coupling phenomena in the EEG bursts during BSP can be regarded as indicators for short-term interrelations between the underlying electrophysiologic processes.

CONCLUSIONS

It can be suggested that the method introduced for the quantification of the sedation depth should be used.

Intraoperative B-mode endosonography of tongue carcinoma

BACKGROUND

Exact estimation of a tumor's size and definition of adequate resection margins in carcinomas of the tongue are often difficult because of the tumor's extension and deep infiltration.

METHODS

We developed a method that allows intraoperative visualization and marking of tumor margins: intraoperative endosonography was performed in five patients with carcinomas of the tongue with an 8- to 12-MHz linear array transducer. The oral cavity was flooded with normal saline solution, and the transducer was immersed therein. This allowed scanning in a noncontact mode. The tumor margins were marked with a surgical suture under endosonographic monitoring.

RESULTS

In the five patients studied, histologic margins corresponded to sonographic margins. The sonographic marking proved to be useful during the resection of the tumor, and histologic safety margins were respected in each case.

CONCLUSIONS

This noninvasive procedure provides a quick and reliable orientation during resection of tongue carcinoma, and a more precise and individual definition of resection margins is possible. Intraoperative noncontact use of endosonography is a promising method, and further studies may confirm this.

Quantification of transient quadratic phase couplings within EEG burst patterns in sedated patients during electroencephalic burst-suppression period

The time dynamics of the quadratic phase coupling within burst patterns during electroencephalic burst-suppression has been quantified. It can be shown that a transient quadratic phase coupling (QPC) exists between the frequency ranges 0 to 2.5 and 3 to 7.5 Hz and between the frequency ranges 0 to 2.5 and 8 to 12 Hz. The QPC can be explained by an amplitude modulation, where the slow rhythm modulates the rhythmic activities with a higher frequency. By means of time-variant bicoherence analysis, a strong phase-locking between the modulating and the modulated component can be identified. The phase-locking is demonstrable within the first 250 ms after the burst onset and comes up to the maximum between 750 and 1250 ms. The effect is maintained over the whole first part of the burst (2 s) with a decreasing tendency after 1250 ms. All these effects cannot be found in the EEG before entering the burst suppression period (BSP). The transient coupling phenomena in the EEG bursts during BSP can be regarded as indicators for short-term interrelations between the underlying electrophysiologic processes.

Sonography of nasal tip anatomy and surgical tip refinement

The amorphous or wide nasal tip is the most commonly encountered nasal tip deformity, but little has been done to measure the effect of standard rhinoplasty techniques on nasal tip width. In the clinical routine, nasal tip width and soft-tissue cover thickness are estimated by inspection and palpation rather than by measurement. In this study, a B-mode sonograph with a 12-MHz transducer was used in a noncontact mode to measure tip width 0.5 cm occipital to the tip defining point, distance between the alar cartilage domes, and thickness of the soft-tissue cover overlying the lower lateral cartilages. These parameters were measured 3 to 8 weeks before and 56 days to 19 months after a transdomal suture tip plasty in 18 patients. The distance between the alar cartilage domes seemed to be an important factor for tip width because interdomal distance, not soft-tissue cover thickness, correlated with tip width before surgery (correlation: 0.53). Conversely, the degree of tip refinement correlated with preoperative soft-tissue cover thickness (correlation: 0.75), but not with interdomal distance. Ultrasonic imaging of nasal soft tissues may help to assess the effect of different tip refining procedures and other soft-tissue changes after rhinoplasty.