Clinical on-site monitoring of ß-lactam antibiotics for a personalized antibiotherapy.

An appropriate antibiotherapy is crucial for the safety and recovery of patients. Depending on the clinical conditions of patients, the required dose to effectively eradicate an infection may vary. An inadequate dosing not only reduces the efficacy of the antibiotic, but also promotes the emergence of antimicrobial resistances. Therefore, a personalized therapy is of great interest for improved patients' outcome and will reduce in long-term the prevalence of multidrug-resistances. In this context, on-site monitoring of the antibiotic blood concentration is fundamental to facilitate an individual adjustment of the antibiotherapy. Herein, we present a bioinspired approach for the bedside monitoring of free accessible ß-lactam antibiotics, including penicillins (piperacillin) and cephalosporins (cefuroxime and cefazolin) in untreated plasma samples. The introduced system combines a disposable microfluidic chip with a naturally occurring penicillin-binding protein, resulting in a high-performance platform, capable of gauging very low antibiotic concentrations (less than 6 ng ml-1) from only 1 µl of serum. The system's applicability to a personalized antibiotherapy was successfully demonstrated by monitoring the pharmacokinetics of patients, treated with ß-lactam antibiotics, undergoing surgery.

Designed miniaturization of microfluidic biosensor platforms using the stop-flow technique.

Here, we present a novel approach to increase the degree of miniaturization as well as the sensitivity of biosensor platforms by the optimization of microfluidic stop-flow techniques independent of the applied detection technique (e.g. electrochemical or optical). The readout of the labeled bioassays, immobilized in a microfluidic channel, under stop-flow conditions leads to a rectangular shaped peak signal. Data evaluation using the peak height allows for a high level miniaturization of the channel geometries. To study the main advantages and limitations of this method by numerical simulations, a universally applicable model system is introduced for the first time. Consequently, proof-of-principle experiments were successfully performed with standard and miniaturized versions of an electrochemical biosensor platform utilizing a repressor protein-based assay for tetracycline antibiotics. Herein, the measured current peak heights are the same despite the sextuple reduction of the channel dimensions. Thus, this results in a 22-fold signal amplification compared to the constant flow measurements in the case of the miniaturized version.

Self-assembled magnetic bead chains for sensitivity enhancement of microfluidic electrochemical biosensor platforms.

In this paper, we present a novel approach to enhance the sensitivity of microfluidic biosensor platforms with self-assembled magnetic bead chains. An adjustable, more than 5-fold sensitivity enhancement is achieved by introducing a magnetic field gradient along a microfluidic channel by means of a soft-magnetic lattice with a 350 µm spacing. The alternating magnetic field induces the self-assembly of the magnetic beads in chains or clusters and thus improves the perfusion and active contact between the analyte and the beads. The soft-magnetic lattices can be applied independent of the channel geometry or chip material to any microfluidic biosensing platform. At the same time, the bead-based approach achieves chip reusability and shortened measurement times. The bead chain properties and the maximum flow velocity for bead retention were validated by optical microscopy in a glass capillary. The magnetic actuation system was successfully validated with a biotin-streptavidin model assay on a low-cost electrochemical microfluidic chip, fabricated by dry-film photoresist technology (DFR). Labelling with glucose oxidase (GOx) permits rapid electrochemical detection of enzymatically produced H2O2.

Treatment of a giant orbitofacial vascular malformation and ophthalmic artery aneurysms with intralesion glue injections: case report.

We describe a giant left orbital vascular malformation that was treated with both percutaneous and transarterial embolization. Feeder artery aneurysms thrombosed as a result of retrograde reflux of embolic material into the distal ophthalmic artery. In this presentation, we emphasize the efficacy of percutaneous embolization and retrograde thromboses of two intradural saccular ophthalmic artery aneurysms.

Effects of trimetazidine on oxidant/antioxidant status in trinitrobenzenesulfonic acid-induced chronic colitis.

Trimetazidine (TMZ), an anti-ischemic agent with proposed antioxidant properties, was used in a chronic colitis model in order to evaluate its effectiveness as a therapeutic agent in chronic colitis. Treatment of male Swiss Albino rats with ethanol (50%) and trinitrobenzenesulfonic acid (TNBS) (30 mg/kg) produced colitis as evidenced by histopathologic damage and inflammatory alterations, lipid peroxidation [increased malondialdehyde (MDA) levels], and enhanced neutrophil infiltration [increased myeloperoxidase (MPO) activity] without marked change in glutathione status. Administration of TMZ (5 mg/kg) to TNBS-treated rats failed to affect the TNBS-induced changes in histopathology and MPO activities. Unexpectedly, intrarectal (i.r.) administration of TMZ significantly elevated colonic MDA levels to a greater extent than TNBS alone. Intraperitoneal (i.p.) TMZ treatment seemed to increase total glutathione (tGSH), GSH, and GSH/GSSG values. In conclusion, our results demonstrated that (a) i.r. administration of ethanol and TNBS is an effective way of inducing a chronic colitis model, (b) inflammation and lipid peroxidation augment tissue damage in the chronic colitis model, (c) i.p. TMZ treatment significantly inhibits MDA production in the chronic colitis model, (d) TMZ treatment is more effective via the i.p. compared to i.r. route, and (e) TMZ seems to show its antioxidant effect via preserving the tissue's GSH/GSSG ratios.

Comparison of the bond compatibility of titanium and an NiCr alloy to dental porcelain.

OBJECTIVES: The aim of this study was to investigate the bond compatibility between porcelain and titanium, by using three-point bending, oxide adherence and thermal expansion tests, and to compare the results with those of a conventional NiCr alloy-porcelain system. METHODS: The three-point bending test was used and the results were evaluated according to DIN draft 13927. Fractured surfaces of the metal and porcelain were examined macroscopically. The oxide adherence test was applied to titanium and NiCr alloy with appropriate oxidation degrees. After an oxide film was formed on the specimens, tensile strength test was applied. Oxide adherence strength values were set and fractured surfaces were examined macroscopically. In the thermal expansion test, thermal expansion curves and thermal expansion coefficients of titanium, NiCr alloy and tested porcelains were determined. Differences in thermal expansion values (delta alpha) in all metal-porcelain pairs were calculated to allow inferences to be made about residual stress levels. RESULTS: The bending strengths of all groups were found to be within the acceptable standard levels. At the end of the oxide adherence test, the results indicated that the adherence of the formed oxides to the metals were at a desired level. As a result of the thermal expansion test, the titanium-porcelain and NiCr-porcelain systems showed compressive thermal stress. However, the titanium-porcelain pair exhibited large positive delta alpha values. This results is found to be above the proposed thermal compatibility. CONCLUSIONS: It was concluded that the bond compatibility between titanium and porcelain was comparable with the NiCr-porcelain system.

Colloid cyst of the third ventricle. Evaluation of 28 cases of colloid cyst of the third ventricle operated on by transcortical transventricular (25 cases) and transcallosal/transventricular (3 cases) approaches.

The clinical and x-ray features of 28 cases of colloid cyst of the third ventricle are described. Colloid cyst is one of the most favourable space-occupying lesions of the brain for successful surgical removal, because an exact pre-operative diagnosis is possible. The surgical approach for colloid cyst of the third ventricle is discussed and the frequency of postoperative seizure is reviewed in 28 cases and compared with the literature.

Results of the combined treatment of paediatric intraspinal tumours.

In this article 98 patients with paediatric intraspinal tumours are presented. All were evaluated according to their ages, sex, signs and symptoms. The patients also had radiological and histopathological studies; and the results of surgical, physical medicine and rehabilitation and of radiotherapy are discussed and compared with the results of patients reported in the literature.

Diagnosis and treatment of intraspinal lipomas.

In this article a 32-case series of intraspinal lipoma localized to the lumbosacral region is presented. All of the patients underwent surgery. Recent reports in the literature indicate that although these lesions show advanced and progressive neurological deficits, very good results can be achieved with surgical treatment. The advantages of computed tomography in diagnosis and the importance of early surgical intervention and postoperative rehabilitation are emphasized.

[Evaluation of accuracy and the time-dependent dimensional stability of silicone based impression materials]. / Silikon esasli ölçü materyallerinde yüzey netliginin ve zaman fonksiyonlu boyutsal stabilitenin degerlendirilmesi.

In the recent years, silicone elastomeric impression materials are widely used in prosthetic dentistry. The accuracy and dimensional stability of these silicone elastomeric impression materials affect the success in their clinical usage. In this study, accuracy and the time-dependent dimensional stability of silicone based impression materials were evaluated. The effect of time is important when using silicone elastomeric impression materials. The result of this study clearly indicated that the silicone impression should be poured as soon as possible.

[Fixed-removable partial denture]. / Sabit-hareketli bolümlü bir protetik tedavi uygulamasi.

Construction of fixed partial dentures involve the restoration and maintenance of oral functions, comfort and appearance very similar to those of the natural dentition. In some cases, the missing teeth and contiguous tissues prevent the reconstruction of desirable fixed partial dentures. Alternative methods should be considered for proper reconstructions involving these cases. In this article, a fixed-removable partial denture application in a patient who had anterior edentulous ridge and extensive supportive tissue loss was demonstrated. This type of denture has the qualities of both the fixed partial denture and the removable partial denture.

[In-vitro-fertilization: chromosome analysis of unfertilized human oocytes]. / In-vitro-Fertilisierung: Chromosomenanalyse unbefruchteter menschlicher Eizellen.

Chromosomal abnormalities and abnormal embryonic development have been observed after human in vitro fertilisation (IVF). Such investigations are not permitted according to the ethical guidelines approved by the IVF team in Berlin ("Berliner Modell"). However, the chromosomal status was studied in oocytes which remained unfertilised in a human IVF programme. In 50 fertilisation attempts the chromosomes of 62 oocytes could be analysed. 45 of the oocytes were in the process of meiotic maturation. One of these showed abnormalities in the first meiotic division and seven during the second meiotic division. After fertilisation in addition to normal embryos, all of which were transferred to the mother, three embryos were triploid and six oocytes were fragmented. The results prove that in human IVF chromosome abnormalities can occur in oocytes already before fertilisation. The importance of the results for later stages of embryonic development is discussed.

Venous malformation of the aqueduct of Sylvius treated by interventriculostomy: 15 years follow-up.

A single venous shunt obstructing the aqueductus of Sylvius was treated by interventriculostomy. A passage for CSF was obtained between the third and fourth ventricles. The catheter which was left in the aqueduct collapsed the malformation, possibly preventing a future haemorrhage. A Simple rubber catheter in the aqueduct of Sylvius has been well tolerated by the patient for 15 years.

Meningiomas of the third ventricle.

Intraventricular third ventricle meningiomas are very rare. Fourteen cases have been previously reported. We present a case of third ventricle meningioma, and discuss aetiology, pathology, symptoms, signs, position in the ventricle, and surgical approaches.