Yeast associated with flower longicorn beetle Leptura ochraceofasciata (Cerambycidae: Lepturinae), with implication for its function in symbiosis.

Wood is difficult for most animals to digest due to large amounts of indigestible polymers, but some wood-feeding insects are considered to be able to utilize it as food with the aid of microbial symbionts. Most members of flower longicorn beetles (Coleoptera: Cerambycidae: Lepturinae) feed on nectar and pollen of flowers as adults and wood as larvae. In some lepturines, associations with yeasts are known: female adults possess fungus-storing organs (termed mycetangia) at ovipositors, and larvae also possess such organs (termed mycetomes) in their midguts to carry the associated yeasts. Despite the high diversity of Lepturinae in the world, lepturine-yeast associations, such as the consistency of associated yeasts among the beetle's developmental stages and ecological function of yeast symbionts, have been poorly documented. Here, we investigated the yeast symbiont of the Japanese common lepturine Leptura ochraceofasciata. X-ray computed microtomography revealed that a pair of tube-like, S-shaped mycetangia was located at the basal part of the ovipositor and that a muscle bundle joined the apex of the mycetangium to spiculum ventrale of sternum VIII. All female adults harbored only one yeast species, Scheffersomyces insectosa, in the mycetangia. All larvae harbored S. insectosa exclusively in the mycetomes. Scheffersomyces insectosa was also recovered from surfaces of eggs. Scheffersomyces insectosa assimilated wood-associated sugars including xylose, cellobiose, and xylan in culture. These results suggest the intimate association between L. ochraceofasciata and S. insectosa: S. insectosa is transmitted from the mother to offspring during oviposition and may be related to larval growth in wood.

Time-course quantitative mapping of caffeine within the epidermis, using high-contrast pump-probe stimulated Raman scattering microscopy.

BACKGROUND: An assessment of the drug penetration and distribution profiles within the skin is essential in dermatology and cosmetology. Recent advances in label-free imaging technologies have facilitated the direct detection of unlabeled compounds in tissues, with high resolution. However, it remains challenging to provide quantitative time-course distribution maps of drugs within the complex skin tissue. The present study aims at acquiring the real-time quantitative skin penetration profiles of topically applied caffeine, by means of a combination of pump-probe phase-modulated stimulated Raman scattering (PM-SRS) and confocal reflection microscopy. The recently developed PM-SRS microscopy is a unique imaging tool that can minimize strong background signals through a pulse-shaping technique, while providing high-contrast images of small molecules in tissues. MATERIALS AND METHODS: Reconstructed human skin epidermis models were used in order to analyze caffeine penetration in tissues. The penetration profiles of caffeine in an aqueous solution, an oil-in-water gel, and a water-in-oil gel were examined by combining PM-SRS and confocal reflection microscopy. RESULTS: The characteristic Raman signal of caffeine was directly detected in the skin model using PM-SRS. Integrating PM-SRS and confocal reflection microscopy allowed real-time concentration maps of caffeine to be obtained from formulation samples, within the skin model. Compared with the conventional Raman detection method, PM-SRS lowered the background tissue-oriented signals and supplied high-contrast images of caffeine. CONCLUSION: We successfully established real-time skin penetration profiles of caffeine from different formulations. PM-SRS microscopy proved to be a powerful, non-invasive, and real-time depth-profile imaging technique for use in quantitative studies of topically applied drugs.

Label-free skin penetration analysis using time-resolved, phase-modulated stimulated Raman scattering microscopy.

Skin penetration analysis of topically applied drugs or active compounds is essential in biomedical applications. Stimulated Raman scattering (SRS) microscopy is a promising label-free skin penetration analysis tool. However, conventional SRS microcopy suffers from limited signal contrast owing to strong background signals, which prevents its use in low-concentration drug imaging. Here, we present a skin penetration analysis method of topical agents using recently developed phase-modulated SRS (PM-SRS) microscopy. PM-SRS uses phase modulation and time-resolved signal detection to suppress both nonlinear background signals and Raman background signals from a tissue. A proof-of-concept experiment with a topically applied skin moisturizing agent (ectoine) in an in vitro skin tissue model revealed that PM-SRS with 1.7-ps probe delay yields a signal contrast 40 times higher than that of conventional amplitude-modulated SRS (AM-SRS). Skin penetration measurement of a topical therapeutic drug (loxoprofen sodium) showed that the mean drug concentration at the tissue surface layer after 240 min was 47.3 ± 4.8 mM. The proposed PM-SRS microscopy can be employed to monitor the spatial and temporal pharmacokinetics of small molecules in the millimolar concentration regime.

Pathways to Mesoporous Resin/Carbon Thin Films with Alternating Gyroid Morphology.

Three-dimensional (3D) mesoporous thin films with sub-100 nm periodic lattices are of increasing interest as templates for a number of nanotechnology applications, yet are hard to achieve with conventional top-down fabrication methods. Block copolymer self-assembly derived mesoscale structures provide a toolbox for such 3D template formation. In this work, single (alternating) gyroidal and double gyroidal mesoporous thin-film structures are achieved via solvent vapor annealing assisted co-assembly of poly(isoprene-block-styrene-block-ethylene oxide) (PI-b-PS-b-PEO, ISO) and resorcinol/phenol formaldehyde resols. In particular, the alternating gyroid thin-film morphology is highly desirable for potential template backfilling processes as a result of the large pore volume fraction. In situ grazing-incidence small-angle X-ray scattering during solvent annealing is employed as a tool to elucidate and navigate the pathway complexity of the structure formation processes. The resulting network structures are resistant to high temperatures provided an inert atmosphere. The thin films have tunable hydrophilicity from pyrolysis at different temperatures, while pore sizes can be tailored by varying ISO molar mass. A transfer technique between substrates is demonstrated for alternating gyroidal mesoporous thin films, circumventing the need to re-optimize film formation protocols for different substrates. Increased conductivity after pyrolysis at high temperatures demonstrates that these gyroidal mesoporous resin/carbon thin films have potential as functional 3D templates for a number of nanomaterials applications.

Mesoporous titanium and niobium nitrides as conductive and stable electrocatalyst supports in acid environments.

The stability of carbon-based catalyst supports represents one of the biggest challenges for the commercialisation of proton-exchange membrane fuel cells (PEMFCs). Metal nitrides are an attractive alternative to carbon-based supports, owing to their high bulk conductivity and acid stability. We report the electrochemical stability evaluation of high-surface-area metal nitrides in acidic electrolytes. Three-dimensional mesoporous titanium (TiN) and niobium nitride (NbN) thin films were prepared using block copolymer self-assembly and were evaluated without using any conductive carbon additives or a carbon-based substrate. Both TiN and NbN are stable and maintain conductivity in acidic electrolytes up to at least 0.85 V (NbN) and 1.4 V (TiN) vs. reversible hydrogen electrode (RHE) after 2000 cycles. We also deposited platinum on the TiN films and demonstrate the expected cyclic voltammogram features, indicating the nitride's utility as a catalyst support.

Role of nitric oxide synthase activity in experimental ischemic acute renal failure in rats.

To determine the role of nitric oxide (NO) in acute renal failure (ARF), we have studied the time course change activities to activity of nitric oxide synthase (NOS) isoform activities, both calcium dependent and independent NOS, in experimental ischemic ARF. We have also analyzed change activities to activity of the NOS activities in both renal cortex and medulla. Male SD rats (n = 5) were inducted to ARF by ischemia-reperfusion injury and divided into the following groups; Control group (sham operation), Day 0 group, (measurement performed on that day of operation), Day 1 group, (measurement performed one day after induction of ARF), Day 3 group and Day 7 group. Measurement of NOS activity was based on the following principles; NO is synthesized from arginine by nitric oxide synthase (NOS) and NO is converted to NO2(-)/NO3(-)(NOx) by oxidation. Detection of the final metabolite of NO, NOx was done using flow injection method (Griess reaction). The results were, (1) calcium dependent NOS activity in the cortex and medulla decreased, however it increased in the recovery period in the renal cortex (Cortex; Control, 0.941 +/- 0.765, D0, 0.382 +/- 0.271, D1, 0.118 +/- 0.353, D3, 2.030 +/- 0.235, D7, 3.588 +/- 2.706, Medulla; Control, 1.469 +/- 0.531, D0, 0.766 +/- 0.156, D1, 0.828 +/- 0.187, D3, 2.078 +/- 0.094, D7, 1.289 +/- 0.313 micromol NOx produced/mg protein/30 min). (2) On the other hand, iNOS activity increased in the early phase of ARF, both in the cortex and medulla, but returned to control values during the recovery phase in cortex and was maintained at higher levels in the medulla (Cortex; Control, 0.333 +/- 0.250, D0, 0.583 +/- 0.428, D1, 1.167 +/- 0.262, D3, 0.250 +/- 0.077, D7, 0.452 +/- 0.292, Medulla; Control, 0.139 +/- 0.169, D0, 0.279 +/- 0.070, D1, 1.140 +/- 0.226, D3, 0.452 +/- 0.048, D7, 0.625 +/- 0.048 micromol NOx produced/mg protein/30 min). These findings suggest that the role of NOS in ARF are different for the different NOS isoforms and have anatomic heterogeneity.

Bacterial meningoencephalitis in patients undergoing chronic hemodialysis: two case reports.

Two patients with bacterial meningoencephalitis (BME) undergoing chronic hemodialysis (HD) are reported. Patient 1 died of bacterial empyema caused by Streptococcus intermedius. Patient 2 was successfully treated by intravenous vancomycin (VCM), panipenem-betamipron and intrathecal VCM. Enterococcus avium from a sacral decubitus ulcer was suggested as a possible pathogen of BME in Patient 2. Autopsy findings in Patient 1 and antimicrobial options in Patient 2 are discussed with a review of the literature. In the two BME patients presented here, sepsis played an important role in their pathogenesis during the chronic HD state.