Propylene oxide in blood and soluble nonprotein thiols in nasal mucosa and other tissues of male Fischer 344/N rats exposed to propylene oxide vapors--relevance of glutathione depletion for propylene oxide-induced rat nasal tumors.

High concentrations of propylene oxide (PO) induced inflammation in the respiratory nasal mucosa (RNM) of rodents. Concentrations > or =300 ppm caused nasal tumors. In order to investigate if glutathione depletion could be relevant for these effects, we determined in PO exposed male Fischer 344/N rats PO in blood and soluble nonprotein SH-groups (NPSH) in RNM and other tissues. Rats were exposed once (6 h) to PO concentrations between 0 and 750 ppm, and repeatedly for up to 20 days (6 h, 5 days/week) to concentrations between 0 and 500 ppm. At the end of the exposures, PO in blood and NPSH in tissues were determined. PO in blood was dependent on concentration and duration of exposure. After the 1-day exposures, NPSH depletion was most distinctive (RNM > liver > lung). Compared to controls, NPSH levels were 43% at 50 ppm PO in RNM and 16% at > or =300 ppm in both RNM and liver. Lung NPSH fell linearly to 20% at 750 ppm. After repeated exposures over 3 and 20 days to 5, 25, 50, 300, and 500 ppm, NPSH losses were less pronounced. At both time points, NPSH were 90%, 70%, 50%, 30%, and 30% of the control values in RNM. Liver NPSH decreased to 80% and 50% at 300 and 500 ppm, respectively. After 20 days, lung NPSH declined to 70% (300 ppm) and 50% (500 ppm). We conclude that continuous, severe perturbation of GSH in RNM following repeated high PO exposures may lead to inflammatory lesions and cell proliferation, critical steps on the path towards tumorigenicity.     

Dose volume histogram analysis of liver radiation tolerance

Eleven patients with carcinoma of the pancreas or biliary system received heavy charged particle radiation treatments and whole liver heavy charged particle radiation at Lawrence Berkeley Laboratory. Doses to the whole liver ranged from 10 to 24 Gray-equivalent (the biological equivalent of 10 to 24 Gray of low-LET photon radiation), whereas the dose to the primary lesion ranged from 53.5 to 70 Gray-equivalent (GyE). The fraction size was 2 to 3 GyE. The liver received partial as well as whole organ irradiation. Integral dose volume histograms for the liver were obtained in all 11 patients. An integral dose volume histogram displays on the ordinate the percentage of liver that was irradiated in excess of the dose specified on the abcissa. In this study, the clinical liver radiation tolerance of these patients is correlated with the information contained in an integral dose volume histogram. One patient developed radiation hepatitis. The integral dose volume histogram of this patient differed from the dose volume histograms of the other 10 patients. This difference was greatest in the range of doses between 30 and 40 GyE. Our results suggest that liver doses in excess of 30 to 35 GyE should be limited to 30% of the liver or less when 18 GyE of whole liver radiation is delivered at 2 GyE per fraction in addition to primary radiation of the pancreas or biliary system.     

Active Crack Obstruction Mechanisms in Crofer® 22H at 650 °C

Increased cyclic loading of components and materials in future thermal energy conversion systems necessitates novel materials of increased fatigue resistance. The widely used 9–12% Cr steels were developed for high creep strength and thus base load application at temperatures below 620 °C. At higher temperature, these materials present unstable grain structure, prone to polygonization under thermomechanical fatigue loading and limited resistance to steam oxidation. This seminal study compares thermomechanical fatigue resistance and long crack propagation of the advanced ferritic-martensitic steel grade 92 and Crofer^® 22H, a fully ferritic, high chromium (22 wt. %) stainless steel, strengthened by Laves phase precipitation. Crofer^® 22H features increased resistance to fatigue and steam oxidation resistance up to 650 °C. Both thermomechanical fatigue (crack initiation) and residual (crack propagation) lifetime of Crofer^® 22H exceeded that of grade 92. The main mechanisms for improved performance of Crofer^® 22H were increased stability of grain structure and “dynamic precipitation strengthening” (DPS). DPS, i.e., thermomechanically triggered precipitation of Laves phase particles and crack deflection at Laves phase-covered sub-grain boundaries, formed in front of crack tips, actively obstructed crack propagation in Crofer^® 22H. In addition, it is hypothesized that local strengthening may occur near the crack tip because of grain refinement, which in turn may be impacted by testing frequency.     

Neurophysiological Markers for Monitoring Exercise and Recovery Cycles in Endurance Sports

The current study analyzes the suitability and reliability of selected neurophysiological and vegetative nervous system markers as biomarkers for exercise and recovery in endurance sport. Sixty-two healthy men and women, endurance trained and moderately trained, performed two identical acute endurance tests (running trial 1 and running trial 2) followed by a washout period of four weeks. Exercise protocol consisted of an acute running trial lasting 60 minutes. An intensity corresponding to 95% of the heart rate at individual anaerobic threshold for 40 minutes was followed by 20 minutes at 110%. At pre-exercise, post-exercise, three hours post-exercise and 24 hours post-exercise, experimental diagnostics on Brain-derived neurotrophic factor (BDNF), heart rate variability (HRV), Stroop Color and Word Test (SCWT), and Short-Form McGill Pain Questionnaire (SF-MPQ) were performed. Significant changes over time were found for all parameters (p < .05). Furthermore, there was an approached statistical significance in the interaction between gender and training status in BDNF regulation (F₍₃₎ = 2.43; p = 0.06), while gender differences were found only for LF/HF-ratio (3hPoEx, F₍₃₎ = 3.40; p = 0.002). Regarding the reliability, poor ICC-values (< 0.5) were found for BDNF, Stroop sensitivity and pNN50, while all other parameters showed moderate ICC-values (0.5-0.75). Plasma-BDNF, SCWT performance, pain perception and all HRV parameters are suitable exercise-sensitive markers after an acute endurance exercise. Moreover, pain perception, SCWT reaction time and all HRV parameters show a moderate reliability, others rather poor. In summary, a selected neurophysiological and vegetative marker panel can be used to determine exercise load and recovery in endurance sports, but its repeatability is limited due to its vaguely reliability. Key points

• Pain perception and the Stroop test have moderate reliability in the use of exercise and recovery markers after two identical exercise loads in endurance sports
• Markers of heart rate variability also show moderate reliability as biomarkers after intense endurance exercise under identical conditions.
• There are associations between neurophysiological markers and inflammatory blood markers after endurance exercise that are partially associated with gender and training status

Key words: NNervous system, monitoring training, biomarkers, reliability, executive function, heart rate variability     

Indications and results of metroplasty in uterine malformations

During 14 years, 430 women with some type of congenital uterine malformation were discovered by different methods, with a rate of 1 in 137 deliveries. In only 17 was metroplasty indicated, because of very poor reproductive performance; out of 42 desired pregnancies, only 14.3% live births resulted. The abortion rate was 65.2%, and there were 13% premature deliveries. The operations performed included the Strassmann type in 13, the Tompkins technique in three and the Jones operation in one. After the metroplasty, out of 27 completed pregnancies the rate of abortions fell in 14.8% (P less than 0.00003) and the rate of live births rose to 85.2% (P less than 0.00003). There is no doubt that when the indication for metroplasty is strictly imposed, the staff is well versed in the different types of operations and the treatment is done in a center which has acquired competence, the improvement in reproductive performance can be quite impressive.     

Tricholemmoma of the eyelid

Tricholemmoma is a benign cutaneous tumor that shows differentiation characteristic of the outer hair sheath. The usual site of occurrence is the face, including the nose and eyelid. Four cases of tricholemmoma involving the eyelid margin to a variable extent are presented and the clinical and pathologic findings are reviewed. In three of the four cases, a histopathologic misdiagnosis of squamous cell carcinoma was initially made. In one case, this resulted in a greater sacrifice of normal lid tissue than was necessary, although the reconstruction yielded a good result. In the subsequent cases, the entity of tricholemmoma was well appreciated before definitive oculoplastic surgery and the referring diagnosis of squamous cell carcinoma was refuted.     

Spectrophotometric determination of pyrrole-like substances in urine of rat and man: An assay for the evaluation of 2,5-hexanedione formed fromn-hexane

Male Wistar rats exposed to atmosphericn-hexane excreted in their urine substances which gave rise to absorption spectra like those of pyrroles after the reaction with Ehrlich's reagent. A simple spectrophometric assay was developed to determine these pyrrole-like substances in urine. Their excretion kinetics were evaluated by exposing rats for 8 h to atmosphericn-hexane concentrations between 50 and 3000 ppm. The dose-response curve revealed saturation kinetics according to Michaelis-Menten, V_max being 1.12 [E ⁵²⁶ml urine/8 hn-hexane exposure] and Km, the atmosphericn-hexane concentration at V_max/2, being 250 ppm. The excretion of pyrrolelike substances closely correlated with that of 2,5-hexanedione measured by Fedtke and Bolt (1987). Pyrrole-like substances were also found in the urine of a male volunteer. When exposing the person for 3 h to atmosphericn-hexane at a concentration of 146 ppm (equivalent to 55 ppm/8 h) the excreted amount was twice the background value. Due to the sensitivity of this assay it is possible to determine pyrrole-like substances in urine according to the present German MAK or US TLV conditions forn-hexane (50 ppm/8 h).     

High acoustic diversity and behavioral complexity of katydids in the Mesozoic soundscape

Acoustic communication has played a key role in the evolution of a wide variety of vertebrates and insects. However, the reconstruction of ancient acoustic signals is challenging due to the extreme rarity of fossilized organs. Here, we report the earliest tympanal ears and sound-producing system (stridulatory apparatus) found in exceptionally preserved Mesozoic katydids. We present a database of the stridulatory apparatus and wing morphology of Mesozoic katydids and further calculate their probable singing frequencies and analyze the evolution of their acoustic communication. Our suite of analyses demonstrates that katydids evolved complex acoustic communication including mating signals, intermale communication, and directional hearing, at least by the Middle Jurassic. Additionally, katydids evolved a high diversity of singing frequencies including high-frequency musical calls, accompanied by acoustic niche partitioning at least by the Late Triassic, suggesting that acoustic communication might have been an important driver in the early radiation of these insects. The Early—Middle Jurassic katydid transition from Haglidae- to Prophalangopsidae-dominated faunas coincided with the diversification of derived mammalian clades and improvement of hearing in early mammals, supporting the hypothesis of the acoustic coevolution of mammals and katydids. Our findings not only highlight the ecological significance of insects in the Mesozoic soundscape but also contribute to our understanding of how acoustic communication has influenced animal evolution.

The production of acoustic signals is one of the most important behavioral adaptions in animal communication, and the sending and receiving messages using sound is essential for the survival and success of many animals. Acoustic communication can be defined as the transmission of messages via airborne sound waves and is enabled by specialized hearing and sound-producing organs (1–4). It is widespread in two disparate extant animal taxa: insects and vertebrates, the latter including frogs, reptiles, birds, and mammals. Animal acoustic communication serves many purposes, including mating rituals, warning calls, conveying the location of food sources, and social learning, and has led to an amazing diversity and complexity of recent soundscapes (1). Therefore, exploring the evolution of animal acoustics will provide robust evidence for addressing how our modern-day soundscapes came into existence. Moreover, understanding the evolutionary history of animal acoustic behavior is crucial to unveiling how acoustic communication affects large-scale patterns of diversification (1, 2), and knowing how animals have evolved in response to sound pressure (e.g., natural noise) is also a key to the future in predicting how animals will deal with anthropogenic noise stressors (3). Nevertheless, the reconstruction of deep-time acoustic behavior is a major challenge. Using phylogenetic methods based on data from living animals is the most prevalent approach for reconstructing past acoustic behavior (2), although the fossil record of morphological traits permitting the analysis of acoustic communication is rather poor (4).Insects were the first terrestrial animals to use air-borne sound signals for long-distance communication (5). They display an extremely high diversity of auditory systems and sound-producing organs. For example, tympanal ears have evolved at least 18 times independently in diverse taxa of seven extant insect orders (Orthoptera, Mantodea, Hemiptera, Diptera, Neuroptera, Coleoptera, and Lepidoptera), involving at least 15 body locations (6, 7). The ability to produce a sound that can travel over a long distance using specialized organs, such as a stridulatory (vibration-producing) apparatus or tymbals, has evolved at least in six insect orders, Blattodea, Orthoptera, Mantodea, Hemiptera, Coleoptera, and Lepidoptera (6). These insects provide important clues for understanding the evolutionary processes driving the diversity of acoustic signaling and behavior (1, 6, 8).Among acoustically signaling insects, katydids (Orthoptera: Tettigoniidae, Prophalangopsidae, and extinct Haglidae) stand out as an ideal model to investigate the evolution of acoustic organs and behavior (1, 8–10). Male katydids produce sounds through friction between specialized veins of the forewings (tegminal stridulation), and these sounds are received by males and females primarily through the ears (auditory tympana) on the protibiae (11) (Fig. 1A). Their sophisticated acoustic communication, an important innovation in sexual selection, has been intensively studied from behavioral, neurological, and evolutionary perspectives (1, 5, 6, 10, 12–22). Although katydids have a rich fossil record dating back to the Triassic, songs have been inferred from only three species: one from the Middle Jurassic (14) and the others from the Early Eocene (13, 15). Therefore, the early evolution of their acoustic communication remains unclear. More importantly, Mesozoic katydid high-frequency songs are thought to be related to hearing improvement in early mammals (5, 12, 23). However, only low-frequency pure-tone (musical) songs have been reported in extinct katydids (13–15), and the origin of high-frequency songs remains unknown (12, 13, 17).Open in a separate windowFig. 1.Prophalangopsidae and Haglidae from the Jurassic Daohugou Konservat-Lagerstätte. (A) Sigmaboilus sinensis, NND04329, male, with stridulatory files and tympanal ears. (B) Tympanal ears on forelegs (enlargement of boxed area in a). Note the right external (posterior) and left internal (inner) tympana are of similar size. (C) Sigmaboilus sinensis, NND04334, female, tympanal ears (SI Appendix, Fig. S1A). (D) Sigmaboilus sp., NND12z088, female, tympanal ear (SI Appendix, Fig. S1B). (E) Liassophyllum caii, NND12z186, male, stridulatory file (SI Appendix, Fig. S2C). (F) Allaboilus gigantus, NND12z171, male, stridulatory file, and harp (SI Appendix, Fig. S2D). ey, eye; ha, harp; hl, hind leg; sf, stridulatory file; te, tympanal ear. (Scale bars, 10 mm (A), 1 mm (B–F).)In this study, we describe the exceptionally preserved stridulatory and hearing organs of katydids from the Middle Jurassic Daohugou Konservat-Lagerstätte (approximately 160 Mya) in China. Furthermore, we reexamine some key fossils from the Triassic of South Africa and Kyrgyzstan and compile an updated database of Mesozoic katydids. Using this, we calculate the singing frequencies of Mesozoic katydids, reconstruct their potential acoustic behavior, and analyze the evolution of their acoustic communications. Our results demonstrate that Mesozoic katydids evolved a high diversity of singing frequencies, acoustic niche partitioning, complex acoustic communication, and high-frequency musical calls.