First use of flat-panel computed tomography during cochlear implant surgery : Perspectives for the use of advanced therapies in cochlear implantation.

BACKGROUND: Cochlear implantation in routine cases with normal anatomy is commonly performed without intraoperative image guidance. Revision cochlear implantation as well as surgery in malformations require not only a precise understanding of the underlying complex anatomy, but surgeons need to transform two-dimensional computed tomography (2D CT) scans into the surgical field and use this information for intraoperative surgical navigation. So far, information about the exact position of the electrode during insertion cannot be provided to the surgeon. Here, we present our first operative experience with cochlear implant surgery supported by intraoperative Dyna-CT technology, providing the surgeon with detailed views of the electrode location. METHODS: To prove the feasibility of the procedure, two cases of cochlear implantation were performed with intraoperative application of cone-beam CT acquired by a C-arm Dyna-CT system (Artis Zeego, Siemens Healthcare, Erlangen, Germany). Image reconstruction was performed intraoperatively in order to assess the correct positioning of the electrodes. RESULTS: Intraoperative Dyna-CT enabled clear visualization of the surgical anatomy and intracochlear electrode position. Dyna-CT technology can be applied with acceptable additional time requirements without adding too much complexity to the surgical procedure. CONCLUSION: Intraoperative data acquisition by Dyna-CT represents a suitable option for online surgical navigation during cochlear implant surgery. This imaging technology will push further advances in cochlear implant surgery and lateral skull base surgery, particularly if linked to intraoperative navigation.

Pilot-scale anaerobic submerged membrane bioreactor (AnSMBR) treating municipal wastewater: the fouling phenomenon and long-term operation.

An anaerobic submerged membrane bioreactor (AnSMBR) on pilot-scale treating a mixture composed of municipal wastewater and glucose under mesophilic temperature conditions was operated for 206 days. The performance of the AnSMBR was evaluated at different fluxes, biomass concentrations and gas sparging velocities (GSV). GSV was used to control fouling. In addition, the AnSMBR was operated in cycles that included relaxation and backwashing phases. The increase in the transmembrane pressure (fouling rate) was measured under different operational conditions and was used to evaluate the stability of the process. The fouling rate could be controlled for a long period of time at a flux of 7 l m(-2) h(-1) with a GSV of 62 m/h and an average biomass concentration of 14.8 g TSS/L. The membrane was physically cleaned after 156 days of operation. The cleaning efficiency was almost 100% indicating that no irreversible fouling was developed inside the pores of the membrane. The COD removal efficiency was close to 90%. As in anaerobic processes, nutrients were not exposed to degradation and almost no pathogens were found in the effluent, hence the effluent could be used for irrigation in agriculture.

Thermophilic anaerobic digestion in compact systems: investigations by modern microbiological techniques and mathematical simulation.

Thermophilic anaerobic digestion in compact systems can be an economical and ecological reasonable decentralised process technique, especially for rural areas. Thermophilic process conditions are important for a sufficient removal of pathogens. The high energy demand, however, can make such systems unfavourable in terms of energy costs. This is the case when low concentrated wastewater is treated or the system is operated at low ambient temperatures. In this paper we present experimental results of a compact thermophilic anaerobic system obtained with fluorescent in situ hybridisation (FISH) analysis and mathematical simulation. The system was operated with faecal sludge for a period of 135 days and with a model substrate consisting of forage and cellulose for a period of 60 days. The change in the microbial community due to the two different substrates treated could be well observed by the FISH analysis. The Anaerobic Digestion Model no. 1 (ADM1) was used to evaluate system performance at different temperature conditions. The model was extended to contribute to decreased methanogenic activity at lower temperatures and was used to calculate energy production. A model was developed to calculate the major parts of energy consumed by the digester itself at different temperature conditions. It was demonstrated by the simulation study that a reduction of the process temperature can lead to higher net energy yield. The simulation study additionally showed that the effect of temperature on the energy yield is higher when a substrate is treated with high protein content.

Development of an empirical mathematical model for describing and optimizing the hygiene potential of a thermophilic anaerobic bioreactor treating faeces.

Poor sanitation and insufficient disposal of sewage and faeces are primarily responsible for water associated health problems in developing countries. Domestic sewage and faeces are prevalently discharged into surface waters which are used by the inhabitants as a source for drinking water. This paper presents a decentralized anaerobic process technique for handling of such domestic organic waste. Such an efficient and compact system for treating faeces and food waste may be of great benefit for developing countries. Besides a stable biogas production for energy generation, the reduction of bacterial pathogens is of particular importance. In our research we investigated the removal capacity of the reactor concerning pathogens, which has been operated under thermophilic conditions. Faecal coliforms and intestinal enterococci have been detected as indicator organisms for bacterial pathogens. By the multiple regression analysis technique an empirical mathematical model has been developed. The model shows a high correlation between removal efficiency and both, hydraulic retention time (HRT) and temperature. By this model an optimized HRT for defined bacterial pathogens effluent standards can be easily calculated. Thus, hygiene potential can be evaluated along with economic aspects. In this paper not only results for describing the hygiene potential of a thermophilic anaerobic bioreactor are presented, but also an exemplary method to draw the right conclusions out of biological tests with the aid of mathematical tools.

Central and peripheral nervous system immune-mediated demyelinating disease after allogeneic hematopoietic stem cell transplantation.

OBJECTIVE: We aimed to evaluate clinical and diagnostic features of central and peripheral immune-mediated demyelinating disease (CPID) in allogeneic hematopoietic stem cell transplantation (aHSCT) recipients. BACKGROUND: CPID refers to the late-onset, immune-mediated neurological complications following aHSCT, when other frequent differential diagnoses have been ruled out, and when symptoms and signs of systemic GvHD manifestations are absent. METHODS: Case records at the University of Tuebingen, between 2001 and 2015, were screened to identify patients with CPID after aHSCT. RESULTS: Seven patients who developed CPID after aHSCT were identified. The average time interval from aHSCT until onset of CPID was 2.6 (±2.8) years (mean±SD). The most prevalent manifestations of CPID were optic neuritis and/or myelitis and polyneuropathy. Cerebrospinal fluid analyses involved elevated protein concentration and lymphocytic pleocytosis, while oligoclonal bands in CSF, but not in serum, were detected in 28% of cases. Aquaporin-4-antibodies were consistently absent. MRI studies showed features suggestive of demyelination processes, with cerebral and/or spinal cord white-matter involvement, and features compatible with cerebral vasculitis. Corticosteroids, Immunoglobulins, Cyclophosphamide, Rituximab and Interferon beta-1a showed marginal treatment responses, whereas plasma exchange resulted in marked clinical improvement in two treated patients. A chronic disease-course with persisting neurological deficits was prevalent. CONCLUSIONS: CPID may comprise a rare complication of aHSCT, which manifests as optic neuritis and/or myelitis and is accompanied by sensorimotor polyneuropathy. A concomitant systemic manifestation of GvHD is not mandatory for CPID diagnosis. Usually, CPID exhibits a chronic, persisting disease course. Thus, clinical awareness is required, as early diagnosis and aggressive treatment may be prognostically advantageous.

Zoomed EPI DWI of Acute Spinal Ischemia Using a Parallel Transmission System.

PURPOSE: A new method for diffusion-weighted imaging (DWI) using independent parallel transmission technique resulting in zoomed DWI was applied in four patients suffering from acute spinal cord ischemia. METHODS: Four patients with clinical symptoms of acute spinal cord ischemia were examined on a 3 T MR-system equipped with a two-channel transmit array. Scans included T2-weighted turbo spin echo, conventional DWI, and zoomed DWI. Image evaluation was performed with regard to overall image quality, anatomic delineation of the spinal cord, and the level of confidence to establish the diagnosis of spinal cord ischemia. RESULTS: Through spatially selective excitation, zoomed DWI allows for acquisition of high-resolution images with reduced scan time due to a reduced field of view in phase-encoding direction, resulting in zoomed images. In all cases the ischemia was demonstrated in conventional DWI as well as zoomed DWI. CONCLUSIONS: Compared to conventional DWI, zoomed DWI enables a faster image acquisition and allowed a more detailed analysis of the spinal lesion which may be critical to attribute the lesion to a particular vessel territory.

Subcutaneous glucose concentration in humans. Real estimation and continuous monitoring.

OBJECTIVE: To determine the real subcutaneous glucose concentration in healthy volunteers to help in the development of new calibration methods for subcutaneous glucosensors. RESEARCH DESIGN AND METHODS: We developed a new method to estimate the real subcutaneous glucose concentration based on the recirculation of phosphate-buffered saline (PBS) in a microdialysis probe inserted into the subcutaneous tissue. Tissue glucose diffuses into the probe until complete equilibration between the glucose concentration outside and inside the microdialysis probe is achieved. Later, the glucose content of the recirculated PBS is assessed in vitro. We applied the method in 10 healthy volunteers under fasting state and during a hyperglycemic clamp. In addition, we monitored the subcutaneous glucose with an enzymatic-amperometric glucosensor combined with a microdialysis probe. RESULTS: The subcutaneous glucose concentration measured by the recirculation method was 72 +/- 6 and 78 +/- 6% of the blood glucose measured in the fasting state and during the hyperglycemic clamps, respectively. On the other hand, the glucosensor's signal correlated significantly with the blood glucose. CONCLUSION: The recirculation method estimated the real subcutaneous glucose concentration, opening the way to develop new calibration procedures for subcutaneous glucosensors. However, a suitable calibration procedure is still lacking.

Feasibility of Noninvasive Diagnosis and Treatment Planning in a Case Series with Carotid-Cavernous Fistula using High-Resolution Time-Resolved MR-Angiography with Stochastic Trajectories (TWIST) and Extended Parallel Acquisition Technique (ePAT 6) at 3 T.

PURPOSE: The evaluation of carotid-cavernous fistulas (CCFs) and the intracranial vasculature has been predominantly carried out using conventional digital subtraction angiography (DSA). Recent developments in time-resolved magnetic resonance angiography (MRA) provide the opportunity to assess both multiple arterial and venous phases with high temporal and spatial resolution. Here, we investigated the feasibility of this technique to functionally assess CCF prior to intervention. METHODS: Six consecutive patients with clinical symptoms of a CCF were scheduled for clinically indicated MRA and underwent a protocol that comprised conventional imaging sequences and high resolution time-resolved MRA with interleaved stochastic trajectories (TWIST). The location of the fistulous communication, the flow pattern, and venous drainage were determined by time-resolved MRA and compared with DSA which was available in five out of six patients. RESULTS: Typical morphological findings (including enlargement of the superior ophthalmic vein, exophthalmos) were found in all cases in both conventional MRI and time-resolved MRA source data. The temporal resolution of time-resolved MRA enabled a good separation of the early filling of the cavernous sinus during the arterial phase. Direct fistulous communication was assessed in three patients with good correlation to DSA, whereas indirect CCF could not definitely be visualized. The time-resolved MRA provided information about the flow pattern and the venous drainage of the fistula in all patients, which is essential for therapy planning. CONCLUSION: Time-resolved MRA provides important morphological and functional information in patients with CCF. Although DSA remains the gold standard for diagnosis and exact classification of fistulas, time-resolved MRA can provide the relevant hemodynamic information to plan interventional treatment as a one-step procedure with a focused diagnostic workup.

Multiple symmetric lipomatosis: abnormalities in complex IV and multiple deletions in mitochondrial DNA.

Multiple symmetric lipomatosis (MSL) is a rare disorder of middle life characterized by large nonencapsulated lipomas distributed around the neck, shoulders, and other axial regions. Neurologic involvement, particularly peripheral neuropathy, is frequent. The pathogenesis of the syndrome is still unknown, but ragged-red fibers are occasionally present in muscle of affected patients, suggesting a mitochondrial abnormality. We studied 11 unrelated patients with MSL by means of neurophysiology, muscle morphology, muscle biochemistry, Southern blot, and PCR analysis of mitochondrial DNA. All patients were men aged 41 to 63 years. Clinical or electrophysiologic signs of a sensorimotor polyneuropathy were present in nine patients, eight of whom had a history of alcoholism. In muscle biopsy specimens, the most prominent feature was pathologic subsarcolemmal aggregates of mitochondria. Biochemical analysis of respiratory chain enzymes revealed a moderate but significant decrease of cytochrome c oxidase activity as compared with age-matched controls. In one patient, Southern blot analysis showed multiple deletions of mitochondrial DNA. We conclude that mitochondrial dysfunction is common in MSL and may be based on identifiable defects in the mitochondrial genome.

Effects of celiprolol on serum lipids in systemic hypertension.

Antihypertensive therapy with celiprolol lowers blood pressure by selectively blocking beta 1 adrenoceptors. It also exhibits vasodilatory and bronchosparing effects and is not cardiodepressive. Because many beta blockers are often suspected of adversely raising serum lipid levels, especially triglycerides, a special investigation of lipids in hypertensive subjects was performed. The preliminary findings in a series of 14 patients (average age 39.7 years) with essential hypertension (World Health Organization stages I to II) who were treated with celiprolol for a period of 6 months are presented. Serum levels of total cholesterol and low-density lipoprotein remained virtually unchanged during treatment. There was, however, a tendency for triglyceride levels to fall with celiprolol treatment, a trend that became significant after 4 weeks. Moreover, high-density lipoproteins tended to increase with treatment and were significantly increased after 2 weeks. In contrast to findings obtained with other beta-blocking agents, no increases in total serum lipids were observed during celiprolol treatment. Blood pressure values of the subjects treated decreased significantly from a mean value (measured in the upright position) of 151/99 to 131/87 mm Hg. Blood pressure values taken in the supine position were also significantly reduced. No significant changes were noted in a variety of laboratory parameters, including blood count, blood coagulation time, blood sugar concentration, liver and kidney tests, electrolyte levels and urinalysis. The significance of these results, which suggest that celiprolol is not associated with adverse changes of lipids and may even positively influence blood chemistry, is discussed.

Reduction of left ventricular hypertrophy in hypertensive patients after treatment with celiprolol.

Long-term treatment with celiprolol, a new cardioselective beta blocker, significantly reduced blood pressure in 14 patients with essential hypertension (World Health Organization stages I to II). Heart rates remained within the normal range throughout treatment and no significant side effects were observed. In 4 patients, end-systolic septum thickness was measured, and evidence was obtained that the extent of left ventricular hypertrophy was reduced. These findings indicate that celiprolol can be used for the successful long-term treatment of essential hypertension, and that such treatment reduces left ventricular hypertrophy induced by high blood pressure.

On line continuous monitoring of blood lactate in men by a wearable device based upon an enzymatic amperometric lactate sensor.

A wearable device for the continuous measurement of lactate in the blood was constructed by the combination of continuous blood sampling employing a double lumen catheter with an amperometric lactate sensor. In vitro, the lactate sensor turned out to have a linear concentration range between 0 and 15 mmol/l. The response time of the sensor itself amounted to 100 sec, whereas the lag time for blood sampling amounted to 2.2 min. In vivo, the lactate sensor was successfully used for the detection of changes of the blood lactate concentration following strenuous exercise in 7 healthy volunteers, in two cases up to 22 h. In conclusion, the technique of continuous blood sampling by the use of a double lumen catheter in combination with the amperometric lactate sensor is feasible and simplifies frequent blood lactate estimations.

Long-term experiences with a computerized diabetes management and glucose monitoring system in insulin-dependent diabetic patients.

Only a minority of patients use diabetes management systems. In our study, 24 patients were given a memory based blood glucometer (ROMEO, Diva Medical Systems), which additionally allowed the input of insulin doses, food intake and exercise for up to four years. Eight patients returned ROMEO within one month (group I), 8 used the system as long it was available as a loan (group II) and 8 patients bought the system (group III). The patients of group III had a significantly better diabetic control (HbA1 = 7.8% +/- 0.7 (S.D.) vs. 11.7 +/- 3.6 (group I) and 10.7 +/- 2.6 (group II)) and were more reliable in their input of the data. After 3 years, however, only five patients of group III continued to use the system, but as a glucose meter only. One patient used the options of the system. These data show that glycemic control is not a question of the equipment. After a certain period, even the well-motivated patients do not use the system options routinely. Obviously, the advantages of the system are only used by a minority of patients characterized by good metabolic control and good compliance, and even these patients do not persistingly use all the options of the system after a certain period of time.

Aerobic thermophilic treatment of sewage sludge contaminated with 4-nonylphenol.

4-Nonylphenol (4-NP) occurs in sewage sludge as a result of the breakdown of detergents which contains nonylphenol ethoxylates (NPEs). 4-NP is of environmental concern because of its toxicity to biological systems. The present paper reports results of aerobic treatment under thermophilic conditions of sewage sludge artificially contaminated with 4-NP. Experiments were carried out using three parallel laboratory-scale batch reactors operating with blank, 50 and 100 mg/l of 4-NP concentration. For the two studied concentrations up to 66% 4-NP reduction was achieved at a specific air flow rate of 16 l/(l.h) and a thermophilic temperature of 60 degrees C, within 10 days of operation. The presence of 4-NP has minor effect on the rate of sludge oxidation and the nitrogen and phosphorous content in the sludge.

Experimental assessment of bio-reduction of di-2-thylhexyl phthalate (DEHP) under aerobic thermophilic conditions.

The reduction of organic contaminants in sewage sludge is of great importance for a further sludge disposal or agricultural utilization. Laboratory scale batch experiments were performed to assess the potential use of the aerobic thermophilic treatment technique to reduce the concentration of difficult to degrade organic chemicals. Di-2-ethylhexyl phthalate (DEHP) was chosen as a model representative of these chemicals. The effect of the sludge temperature and aeration rate on the reduction of DEHP concentration as well as on the reduction of the organic dry solid (oDS) was investigated. With a specific air flow rate of 16 m3/m3.h and a thermophilic temperature of 63 degrees C it was possible to achieve up to 70% reduction of the DEHP concentration and 61% of oDS within 96 hours. The maximum degradation of the oDS matter occurred within the first 24 hours of operation whereby only little oDS was degraded afterward. During the experiments the reactor content was routinely monitored for pH, COD, along with the ammonia nitrogen and orthophosphate concentrations.

Persistent cerebellar deterioration in a patient with lobar pneumonia under lithium, carbamazepine, and trifluperidol treatment.

We report on a patient with schizoaffective disorder who was on combination therapy of lithium, carbamazepine, and the neuroleptic trifluperidol. He experienced a lobar pneumonia and developed an acute and persistent cerebellar deterioration which was most likely due to lithium toxicity, while the serum lithium level was within the therapeutic range. The combination of lithium, carbamazepine, and neuroleptics is common, and is generally considered to be safe. The reported case suggests that this regimen might increase the risk of intoxication with potentially disabling side-effects.

Use of the microdialysis technique in the monitoring of subcutaneous tissue glucose concentration.

For some time the subcutaneous (s.c.) tissue has been the target for continuous glucose measurement. The microdialysis technique permits an extracellular region approach, which has been used for about two decades for measuring various metabolites in dialysates obtained from different body regions. By connecting a s.c. implanted microdialysis probe to a flow chamber of an amperometric glucose sensor, the procedure of glucose sensing was transferred to ex vivo. Using this device it was possible to obtain, for up to 24 hours, s.c. tissue glucose profiles of healthy and diabetic people. The microdialysis theory, the calibration process and other microdialysis technique applications are discussed in this paper. Although the combination of the microdialysis technique and amperometric glucose sensing requires certain technical equipment, the combination of microdialysis and glucose sensor seems to be a promising approach to a continuously functioning glucose sensing system.

Thermal hydrolysis (TDH) as a pretreatment method for the digestion of organic waste.

The recycling concept under consideration is based on the process of Thermal Hydrolysis (TDH) followed by an anaerobic digestion. By increasing pressure and temperature the organic part of the waste is split up in a first step into short-chain fragments that are biologically well suited for microorganisms. The following fermentation runs much faster and more complete than in conventional digestion processes and the biogas yield is increased. Left is just a small amount of a solid residue that can be easily dewatered and utilized as surrogate fuel for incineration or as compost additive. The thermal hydrolysis process allows a complete energy recovery from organic waste. During the total procedure more energy sources are produced than are needed for running the plant. The procedure is especially suited for wet organic waste and biosolids that are difficult to compost, such as food scraps, biological waste from compact residential areas and sewage sludge. As a complete disinfection is granted due to the process temperatures the procedure is also suited for carcasses.