Phase measurements on terahertz waves.

The change in phase of the free space terahertz (THz) electric field as a sample of material introduced into the THz beampath of a CW THz system is measured and used to calculate the index of refraction of materials at 250 GHz.

Arxula adeninivorans recombinant adenine deaminase and its application in the production of food with low purine content.

AIMS: Construction of a transgenic Arxula adeninivorans strain that produces a high concentration of adenine deaminase and investigation into the application of the enzyme in the production of food with low purine content. METHODS AND RESULTS: The A. adeninivorans AADA gene, encoding adenine deaminase, was expressed in this yeast under the control of the strong inducible nitrite reductase promoter using the Xplor(®) 2 transformation/expression platform. The recombinant enzyme was biochemically characterized and was found to have a pH range of 5.5-7.5 and temperature range of 34-46 °C with medium thermostability. A beef broth was treated with the purified enzyme resulting in the concentration of adenine decreasing from 70.4 to 0.4 mg l(-1). CONCLUSIONS: It was shown that the production of adenine deaminase by A. adeninivorans can be increased and that the recombinant adenine deaminase can be used to lower the adenine content in the food. SIGNIFICANCE AND IMPACT OF THE STUDY: Adenine deaminase is one component of an enzymatic system that can reduce the production of uric acid from food constituents. This study gives details on the expression, characterization and application of the enzyme and thus provides evidence that supports the further development of the system.

Arxula adeninivorans xanthine oxidoreductase and its application in the production of food with low purine content.

AIMS: Isolation and characterization of xanthine oxidoreductase and its application in the production of food with low purine content. METHODS AND RESULTS: The A. adeninivorans xanthine oxidoreductase is an inducible enzyme. The best inducers were identified by enzyme activity tests and real-time PCR and used to produce large amounts of the protein. Xanthine oxidoreductase was partially purified and biochemically characterized, showing pH and temperature optimum of 8·5 and 43°C, respectively. The enzyme decreased xanthine and hypoxanthine concentrations in yeast extract and was active simultaneously with other purine-degrading enzymes so that all of the substrates for uric acid production were reduced in a single step. CONCLUSIONS: It was shown that induced A. adeninivorans can produce sufficient amount of xanthine dehydrogenase and that the enzyme is able to reduce xanthine and hypoxanthine content in food, and when used in conjunction with other enzymes of the pathway, uric acid concentration is significantly reduced. SIGNIFICANCE AND IMPACT OF THE STUDY: Reduction in dietary purines is recommended to people suffering from hyperuricemia. Elimination of most purine-rich foods may affect balanced nutrition. Food with lowered purine concentration will assist in controlling the disease. This study is a continuation of previous studies that characterized and overexpressed other enzymes of the purine degradation pathway.

[Comparison of the ThinPrep monolayer technique and conventional cervical Pap smears in a high-risk population using the Munich II nomenclature]. / Vergleich der ThinPrep-Dünnschichtzytologie mit der konventionellen zervikalen Exfoliativzytologie in einem Risikokollektiv unter Verwendung der Münchener Nomenklatur II.

OBJECTIVE: In this prospective study using the Munich II nomenclature for cervical cytology. Pap smear results obtained by the ThinPrep monolayer technique and those obtained by the conventional method were compared. METHODS: Pap smears were obtained from 1,000 women using an Ayre spatula/endocervical brush combination. Following transfer of the cell sample onto a slide, the same collection devices were rinsed in a liquid medium and processed using ThinPrep-2000 processor (split-sample technique). RESULTS: Specimen inadequacies due to drying artefacts, cell overlap or low number of epithelial cells were rare with both methods without any significant differences. However, ThinPrep slides were significantly less often compromised by red or white blood cells or by cytolysis. In contrast, endocervical cells were missing in 11.6% of slides compared to only 2.3% in conventional Pap smears. ThinPrep yielded results of unknown significance (Pap III) significantly less often (4.2 vs 6.3%). CONCLUSIONS: ThinPrep slides are less frequently compromised by blood components or cytolysis. Inconclusive results of Pap III are slightly less frequent when using ThinPrep. However, there is a significant percentage of slides lacking the endocervical component. Using a combination of spatula and cytobrush, this may not necessarily be due to non-representative cell sampling.

Serotonin transporter polymorphism modulates neural correlates of real-life joint action. An investigation with functional near-infrared spectroscopy (fNIRS).

A functional polymorphism (5-HTTLPR) within the serotonin transporter gene (SERT) has been associated with personality dimensions such as neuroticism, with emotional reactivity to negative events, and with an increased risk of affective disorders. More specifically, the short (S) allele of 5-HTTLPR has been linked to increased amygdala activity and has been identified as a risk allele for depressive disorders. Recently, Homberg and Lesch (2011) urged for a conceptual change in the current deficit-oriented connotation of the 5-HTTLPR S-allele and argued that the S-allele could be considered adaptive in certain contexts. They postulated that S-allele carriers show hypervigilant behavior in social situations and should thus show increased social conformity. Therefore, we tested whether 5-HTTLPR modulates the neural correlates of real-life social joint action through functional near-infrared spectroscopy (fNIRS). Thirty participants, homozygote for 5-HTTLPR, were measured and analyzed while they were involved in a previously published joint-action paradigm, which reliably leads to an activation of the left parietal cortex. We found that homozygote S-allele carriers showed increased inferior parietal lobe activation, compared to the LL-allele carriers for the contrast "joint action greater solo action". Therefore, our results provide evidence for beneficial effects of the S-allele on the neural correlates of social interactions.

Coexistence of purino- and pyrimidinoceptors on activated rat microglial cells.

1. Nucleotide-induced currents in untreated (proliferating) and lipopolysaccharide (LPS; 100 ng ml(-1)) treated (non-proliferating) rat microglial cells were recorded by the whole-cell patch-clamp technique. Most experiments were carried out on non-proliferating microglial cells. ATP (100 nM-1 mM), ADP (10 nM-10 mM) and UTP (1 microM-100 mM), but not uridine (100 microM-10 mM) produced a slow outward current at a holding potential of 0 mV. The effect of UTP (1 mM) did not depend on the presence of extracellular Mg2+ (1 mM). The outward current response to UTP (1 mM) was similar in non-proliferating and proliferating microglia. 2. In non-proliferating microglial cells, the ATP (10 microM)-induced outward current was antagonized by suramin (300 microM) or reactive blue 2 (50 microM), whereas 8-(p-sulphophenyl)-theophylline (8-SPT; 100 microM) was inactive. By contrast, the current induced by UTP (1 mM) was increased by suramin (300 microM) and was not altered by reactive blue 2 (50 microM) or 8-SPT (100 microM). 3. The current response to UTP (1 mM) disappeared when K+ was replaced in the pipette solution by an equimolar concentration of Cs+ (150 mM). However, the effect of UTP (1 mM) did not change when most Cl- was replaced with an equimolar concentration of gluconate (145 mM). The application of 4-aminopyridine (1 mM) or Cs+ (1 mM) to the bath solution failed to alter the UTP (1 mM)-induced current. UTP (1 mM) had almost no effect in a nominally Ca2+-free bath medium, or in the presence of charybdotoxin (0.1 microM); the inclusion of U-73122 (5 microM) or heparin (5 mg ml(-1)) into the pipette solution also blocked the responses to UTP (1 mM). By contrast, the effect of ATP (10 microM) persisted under these conditions. 4. I-V relations were determined by delivering fast voltage ramps before and during the application of UTP (1 mM). In the presence of extracellular Cs+ (1 mM) and 4-aminopyridine (1 mM) the UTP-evoked current crossed the zero current level near -75 mV. Omission of Ca2+ from the Cs+ (1 mM)- and 4-aminopyridine (1 mM)-containing bath medium or replacement of K+ by Cs+ (150 mM) in the pipette solution abolished the UTP current. 5. Replacement of GTP (200 microM) by GDP-beta-S (200 microM) in the pipette solution abolished the current evoked by UTP (1 mM). 6. When the pipette solution contained Cs+ (150 mM) instead of K+ and in addition inositol 1,4,5,-trisphosphate (InsP3; 10 microM), an inward current absolutely dependent on extracellular Ca2+ was activated after the establishment of whole-cell recording conditions. This current had a typical delay, a rather slow time course and did not reverse its amplitude up to 100 mV, as measured by fast voltage ramps. 7. A rise of the internal free Ca2+ concentration from 0.01 to 0.5 microM on excised inside-out membrane patches produced single channel activity with a reversal potential of 0 mV in a symmetrical K+ solution. The reversal potential was shifted to negative values, when the extracellular K+ concentration was decreased from 144 to 32 mM. By contrast, a decrease of the extracellular Cl- concentration from 164 to 38 mM did not change the reversal potential. 8. Purine and pyrimidine nucleotides act at separate receptors in rat microglial cells. Pyrimidinoceptors activate via a G protein the enzyme phospholipase C with the subsequent release of InsP3. The depletion of the intracellular Ca2+ pool appears to initiate a capacitative entry of Ca+ from the extracellular space. This Ca2+ then activates a Ca2+-dependent K+ current.

Synthesis of bridged medium-sized rings through the intramolecular Pauson-Khand reaction.

[reaction: see text] A series of aromatic enynes containing steric buttressing elements were prepared and evaluated in the NMO-mediated Pauson-Khand cyclization. O-Allyl systems led to the expected angularly fused products, whereas the O-butenyl and O-pentenyl derivatives afforded the unprecedented bridge systems.

A pi-stacked 1,2,3-dithiazolyl radical. Preparation and solid state characterization of (Cl2C3NS)(ClC2NS2).

Crystals of (Cl2C3NS)(ClC2NS2), an isothiazolyl-substituted 1,2,3-dithiazolyl radical, consist of evenly spaced, slipped pi-stacks; magnetic and conductivity measurements indicate the material is a Mott insulator with sigma RT = 2 x 10(-7) S cm-1.

Pentobarbital and brilliant green modulate the current response of recombinant rat kainate-type GluR6 receptor channels differentially.

Kainate-type receptor channels (GluR5-7, KA1,2) belong to the family of ionotropic glutamate receptor channels. In the present study we tested the interaction of two different drugs with GluR6 channels using outside-out patches from HEK cells transiently transfected with cDNA of GluR6 channels. Glutamate and the respective drugs were delivered by a system for ultrafast solution exchange. Application of a saturating concentration of 3 mM glutamate resulted in fast current transients with desensitization time constants between 3 and 10 ms. Addition of pentobarbital (>or=1 mM) to the 3 mM glutamate containing test-solution resulted in a significant decrease of the time constant of current decay without affecting the peak current amplitude. Brilliant green (>or=1 mM) had the opposite effect and led to an increase of the time constant of current decay after application of 3 mM glutamate. The pharmacological effects of both drugs were completely reversible. Additionally, a significant increase of the peak current amplitude and the time constant of deactivation in presence of brilliant green was observed. Summarizing our results, we could identify a further substance, brilliant green, interacting with GluR6 kainate-type receptor channels.

On valid and reliable identification of normal disfluencies and stuttering disfluencies: a response to Aram, Meyers, and Ekelman (1990)

Aram, Meyers, and Ekelman (1990, Brain and Language, 38, 105-121) recently reported finding that children with unilateral brain lesions produced more stuttering-type nonfluencies than their neurologically normal peers. However, they did not report inter- or intrajudge agreement for the nonfluency types or for their method of measuring speech rate. The speech rates they reported were also unusually fast. We argue that these problems with Aram et al.'s study imperil both their results and their conclusions regarding developmental stuttering.

Individual and consensus judgments of disfluency types in the speech of persons who stutter.

Previous research has suggested that the reliability with which judges identify individual disfluency types, such as repetitions or prolongations of speech sounds, may be very poor. The use of disfluency types judgments in research and clinical applications is also complicated by important differences among the several disfluency-based characterizations of stuttered speech. In an attempt to address these problems, this study arranged for 30 judges to identify all disfluency types that they perceived to be present in 5-s audiovisually recorded speech stimuli, each in an Individual task and then with a partner in a Consensus task. Intrapair agreement and interpair agreement for occurrences of disfluency types (from Consensus conditions) were significantly higher than intrajudge and interjudge agreement for occurrences (from Individual conditions). Despite being higher than individual values, however, intrapair and interpair agreement for occurrences both averaged less than 50%. Results also showed that disfluency types judgments, interpreted in terms of three common disfluency-based definitions of stuttering, were not strongly related to previous assessments of whether these speech tokens contained or did not contain stuttering. When combined with previously available data, the present findings suggest caution in the use of disfluency types to describe or define stuttered speech.

Identifying the authoritative judgments of stuttering: comparisons of self-judgments and observer judgments.

Reliable and accurate stuttering measurement depends on the existence of unambiguous descriptions or exemplars of stuttered and nonstuttered speech. The development of clinically meaningful and useful exemplars, in turn, requires determining whether persons who stutter judge the same speech to be stuttered that other observers judge to be stuttered. The purpose of these experiments, therefore, was to compare stuttering judgements from several sources: 15 adults who stutter, judging their own spontaneous speech; the same adults who stutter, judging each other's speech; and a panel of 10 authorities on stuttering research and treatment. Judgments were mode under several conditions, including self-judgments made while the speaker was talking and self- and other-judgements made from recordings in continuous and interval formats. Results showed substantial differences in stuttering judgments across speakers, judges, and judgment conditions, but across-task comparisons were complicated by low self-agreement for many judges. Some intervals were judged consistently by all judges to be Stuttered or Nonstuttered, across multiple conditions, but many other intervals were either not assigned replicable judgments or were consistently judged to be Nonstuttered by the speaker who had produced them but were not assigned consistent judgments by other judges. The implications of these findings for stuttering measurement are considered.

Effects of time-interval judgement training on real-time measurement of stuttering.

The purpose of this study was to investigate whether a previously developed interval-based training program could improve judges' stuttering event judgments. Two groups of judges made real-time stuttering event judgments (computer-mouse button presses) in 3 to 6 trials before the response-contingent judgment training program and in another 3 to 6 trials after training, for recordings of 9 adults who stuttered. Their judgments were analyzed in terms of number of stuttering events, duration of stuttering, and 5-s intervals of speech that could be categorized as judged (or not judged) to contain stuttering. Results showed (a) changes in the amount of stuttering identified by the judges; (b) improved correspondence between the judges' identifications of stuttering events and interval-based standards previously developed from judgments made by experienced, authoritative judges; (c) improved correspondence between interval-based analyses of the judges' stuttering judgments and the previously developed standards; (d) improved intrajudge agreement; (e) improved interjudge agreement; and (f) convergence between the 2 judge groups, for samples and speakers used during training tasks and also for other speakers. Some implications of these findings for developing standardized procedures for the real-time measurement of stuttering are discussed.

Experimental investigation of the effects of frequency-altered auditory feedback on the speech of adults who stutter.

A series of single-subject experiments evaluated the effects of frequency-altered auditory feedback (FAF) on the speech performance of four adult males who stutter. Using alterations of plus or minus one octave, FAF was compared with normal auditory feedback (NAF) in oral reading and spontaneous speech with measurements made of stuttered intervals, stutter-free speech rate, and speech naturalness. The effects of extended FAF conditions on spontaneous speech were also evaluated for two subjects who demonstrated a positive response to FAF. Results showed no consistencies across subjects in responses to FAF: One subject showed no response, another produced an initial temporary response, a third showed a deterioration in speech quality with minimal reductions in stuttering, and a fourth displayed substantial and sustained improvements in speech performance. Some implications of these findings for current research and theory about the relationship between stuttering and FAF are discussed.

[In vitro and in vivo investigations of a modified textile keratoprosthesis. ACTO TexKPRO]. / In-vitro- und In-vivo-Untersuchung einer modifizierten textilen Keratoprothese. ACTO TexKPRO.

BACKGROUND: Clinical application of a keratoprosthesis (KPRO) is still a challenging task. Recent developments reflect the concepts of nut and bolt, intrastromal implantation or an osteoodontokeratoprosthesis (OOKP). A new concept of a textile KPRO has been evaluated in a limited human study with considerable difficulties which after termination of the study and considerable improvements was restarted using animal experiments. MATERIALS: The ACTO TexKPRO is made from polyvinylidene difluoride (PVDF) fibers and transparent silicone. The first and second developmental stages differed in density and size of fibers and furthermore in surface modifications of the fibers and optics which were improved for the second prototype. METHODS: Implantation of the prosthesis was performed in four patients with corneal blindness and in two cases retinal disease which required surgery. In the later animal experiments surgery was performed on three rabbits. Surgery was performed by redressing the conjunctiva, opening of the eyeball with a central 6.5 mm trephination, removal of the lens and iris and implantation and suturing of the TexKPRO. If required a silicone oil endotamponade was placed. RESULTS: All eyes were stable with the keratoprosthesis. The first prototype showed conjunctival recession on the textile haptics with highly susceptible endopthalmitis risk due to infection of the PVDF so that we decided to remove the prosthesis from all eyes after one case of severe endophthalmitis occurred. The longest time of placement was 40 months and the shortest time 6 months. All eyes were restored by keratoplasty. In animals with the new haptic we found better conjunctivalization and stable implantation of the KPRO. DISCUSSION: The textile KPRO provides a stable implantation procedure and safe connection of fibers to the scleral wound bed. The optical and mechanical implantation is safe and stable. Surface epithelialization is improved with the new surface modifications and different PVDF fiber density but beforel new implantations are planned further conceptual changes will be introduced.

[Eye irritation and chemical eye burns. Review of experimental and clinical studies]. / Augenirritation und Augenverätzung. Experimentelle und klinische Übersicht.

Chemical burns of the eye are becoming rare due to improvements in occupational protection. Effective decontamination is the foundation for good clinical results of this ophthalmological emergency. The toxicological aspect focuses on classifying the specific toxicity of a chemical substance by evaluating the degree of eye irritation and eye burns. Chemical substances are classified into defined risk levels by specific tests. The traditional ophthalmological approach is based on the clinical presentation of eye burns as a result of contact with a specific toxic substance. In an integral approach it is shown that substance-specific characteristics, such as concentration and specific reactivity as well as individual features, such as mode and duration of exposition have an influence on the clinical appearance of the tissue damage. The decontamination is dependent on the mode of action and the effectiveness of the decontamination solution. Amphoteric substances have the best effectiveness for decontamination of the eye due to their specific characteristics.