Combined 1-Deoxynojirimycin and Ibuprofen Treatment Decreases Microglial Activation, Phagocytosis and Dopaminergic Degeneration in MPTP-Treated Mice

Inflammation is a predominant aspect of neurodegenerative diseases and experimental studies performed in animal models of Parkinson's disease (PD) suggesting that a sustained neuroinflammation exacerbates the nigrostriatal degeneration pathway. The central role of microglia in neuroinflammation has been studied as a target for potential neuroprotective drugs for PD, for example nonsteroidal anti-inflammatory drugs (NSAIDs) and matrix metalloproteinases (MMP) inhibitors that regulates microglial activation and migration. The aim of this study was to investigate the neuroprotective response of the iminosugar 1-deoxynojirimycin (1-DNJ) and compare its effect with a combined treatment with ibuprofen. MPTP-treated mice were orally dosed with ibuprofen and/or 1-DNJ 1. Open-field test was used to evaluate behavioral changes. Immunohistochemistry for dopaminergic neurons marker (TH⁺) and microglia markers (Iba-1⁺; CD68⁺) were used to investigate neuronal integrity and microglial activation in the substantia nigra pars compacta (SNpc). The pro-inflammatory cytokines TNF-α and IL-6 were analysed by qPCR. Treatments with either 1-DNJ or Ibuprofen alone did not reduce the damage induced by MPTP intoxication. However, combined treatment with 1-DNJ and ibuprofen prevents loss of mesencephalic dopaminergic neurons, decreases the number of CD68⁺/ Iba-1⁺ cells, the microglia/neurons interactions, and the pro-inflammatory cytokines, and improves behavioral changes when compared with MPTP-treated animals. In conclusion, these data demonstrate that the combined treatment with a MMPs inhibitor (1-DNJ) plus an anti-inflammatory drug (ibuprofen) has neuroprotective effects open for future therapeutic interventions. Graphical Abstract MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) is a protoxicant that, after crossing the Blood Brain Barrier, is metabolized by astrocytic MAO-B to MPDP+, a pyridinium intermediate, which undergoes further two-electron oxidation to yield the toxic metabolite MPP+ (methyl-phenyltetrahydropyridinium) that is then selectively transported into nigral neurons via the mesencephalic dopamine transporter. In this study, we demonstrated that MPTP induced death of dopaminergic neurons, microgliosis, increase of gliapses, motor impairment and neuroinflammation in mice, which were inhibited by combined 1-deoxynojirimycin and ibuprofen treatment.

Differential expression of the MHM region and of sex-determining-related genes during gonadal development in chicken embryos

The chicken (Gallus gallus) embryo has been used as a classic model system for developmental studies because of its easy accessibility for surgical manipulation during embryonic development. Sex determination in birds is chromosomally based (ZZ for males and ZW for females); however, the basic mechanism of sex determination is still unknown. Here, the dynamics of expression of candidate genes implicated in vertebrate sex determination and differentiation were studied during embryonic chicken gonadal development. Gene expression profiles were obtained before, during, and after gonadal sex differentiation in females and males for DMRT1, SOX3, SOX9, DAX1, SCII, HINTZ, HINTW, and the male hypermethylated (MHM) region. Transcripts for the HINTZ, DMRT1, DAX1, SCII, and SOX9 genes were observed in both sexes, but expression was higher in male gonads and may be correlated with testicular differentiation. The expression patterns of HINTW, SOX3, and MHM suggest that they may act in ovary development and may be involved in meiosis entry. MHM was upregulated and DMRT1 was downregulated in females at the same developmental stage. This may indicate a regulation of DMRT1 by MHM ncRNA. Similar dynamics were observed between HINTW and HINTZ. This study reports on the MHM expression profile during gonadal development and its correlation with the expression of genes involved in vertebrate sex determination.

Modal interferometer based on hollow-core photonic crystal fiber for strain and temperature measurement

In this work, sensitivity to strain and temperature of a sensor relying on modal interferometry in hollow-core photonic crystal fibers is studied. The sensing structure is simply a piece of hollow-core fiber connected in both ends to standard single mode fiber. An interference pattern that is associated to the interference of light that propagates in the hollow core fundamental mode with light that propagates in other modes is observed. The phase of this interference pattern changes with the measurand interaction, which is the basis for considering this structure for sensing. The phase recovery is performed using a white light interferometric technique. Resolutions of +/- 1.4 microepsilon and +/- 0.2 degrees C were achieved for strain and temperature, respectively. It was also found that the fiber structure is not sensitive to curvature.

Absorption-line-locked fiber laser for gas-sensing applications

An absorption-line-locked fiber laser based on the selection and conversion of a gas absorption line into a highly stable intracavity transmission narrowband filter is demonstrated. The laser has attractive properties for gas-sensing applications due to its frequency stability and multiwavelength selection capability.

All-fiber Mach-Zehnder curvature sensor based on multimode interference combined with a long-period grating

A novel Mach-Zehnder interferometer based on a fiber multimode interference structure combined with a long-period fiber grating (LPG) is proposed. The multimode interference is achieved through the use of a MMF section spliced between two single-mode fibers, with a length adjusted to couple a fraction of light into the cladding modes. A LPG placed after the MMF couples light back into the fiber core, completing the Mach-Zehnder interferometer. This novel configuration was demonstrated as a bending sensor.

Optical flowmeter using a modal interferometer based on a single nonadiabatic fiber taper

A novel in-fiber modal interferometer is presented that is based on a nonadiabatic biconical fused taper that couples light between the cladding and the core, combined with the Fresnel reflection at the fiber end. It is observed that the returned light from this fiber structure shows a channeled spectrum similar to that of a two-wave Michelson interferometer. The application of this device as a fiber optic flowmeter sensor is demonstrated.

Optical inclinometer based on a single long-period fiber grating combined with a fused taper

A new concept to measure rotation angles based on a fiber-optic modal Mach-Zehnder interferometer is demonstrated by using a nonadiabatic taper cascaded with a long-period fiber grating. Information about the magnitude of the rotation angle can be obtained from the measurement of the interference pattern visibility, and under certain conditions it is also possible to obtain the sign of the rotation angle from the induced phase variation in the fiber interferometer.

Intensity-referenced and temperature-independent curvature-sensing concept based on chirped fiber Bragg gratings

An intensity-referenced temperature-independent curvature-measurement technique that uses a smart composite that comprises two chirped fiber Bragg gratings is demonstrated. The two gratings are embedded on opposite sides of the composite laminate and act simultaneously as curvature sensors and as wavelength discriminators, enabling a temperature-independent intensity-based scheme to measure radius of curvature. Also, the system's performance is independent of arbitrary power losses that are induced in the lead fibers to the sensing head. It is demonstrated that the measurement range depends on the relative positions of the chirped fiber Bragg gratings and on their spectral bandwidths. By using two chirped fiber Bragg gratings with bandwidths W1 = 2.8 nm and W2 = 3.7 nm and with central wavelengths at lambda 01 = 1560.3 nm and lambda 02 = 1563.7 nm, we obtained a resolution of 1.6 mm/square root of Hz for the measurement of the radius of curvature (approximately R = 350 mm) over the measurement range 190 mm < R < infinity.

Proteolytic expression in Blastocrithidia culicis: influence of the endosymbiont and similarities with virulence factors of pathogenic trypanosomatids

Blastocrithidia culicis is an insect trypanosomatid that presents bacterial endosymbionts. The cell-associated and secreted proteinases of the endosymbiont-bearing and aposymbiotic strains were compared through the incorporation of proteinaceous substrates into sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Few qualitative changes could be detected in the proteolytic zymograms in the 2 strains studied when gelatin, casein, haemoglobin or bovine serum albumin (BSA) were tested. However, the level of proteolytic activities was significantly higher in the aposymbiotic strain. Some of the B. culicis proteins reacted in Western blots with antibodies raised against gp63, a zinc-metalloproteinase, and cruzipain, a cysteinyl-proteinase, which are virulence factors of the human pathogenic trypanosomatids, Leishmania spp. and Trypanosoma cruzi, respectively. The anti-cross-reacting determinant (CRD) antibody recognized 2 polypeptides (50 and 58 kDa) in the spent culture media and in the supernatant from glycosylphosphatidylinositol-phospholipase C (GPI-PLC)-treated cells, suggesting that these proteins are GPI-anchored to the plasma membrane. In addition, the anti-gp63 reacted with the 50 kDa protein. The identification of protein homologues in trypanosomatids with distinct life-cycles may help to determine the importance of proteinases in trypanosomatids.

Simultaneous determination of curvature, plane of curvature, and temperature by use of a miniaturized sensing head based on fiber Bragg gratings

We present what we believe to be a novel miniaturized sensor configuration based on fiber Bragg gratings for simultaneous measurement of curvature and temperature in smart structures and composite materials. Because of the particular geometry of the sensing head, it is possible not only to measure the radius of curvature but also to determine the plane of curvature. We arrange three Bragg gratings in the vertices of the smallest equilateral triangle that can be defined by the cross sections of the fibers. The set is then inserted into a glue-filled capillary stainless-steel tube to provide both suitable protection for the Bragg sensors and rotational symmetry to the sensing head. This tube also ensures isolation from axial strain, allowing for the additional determination of temperature. The proposed sensing head is particularly well suited for applications in smart structures because it can be embedded along any layer of a composite material (including the neutral line) without special concern for the relative orientation of the Bragg gratings and the composite layers. We can also use this sensing configuration to implement more-sophisticated sensors dedicated, for example, to the measurement of multiaxial acceleration or flow and temperature.

Fiber Bragg grating-based self-referencing technique for wavelength-multiplexed intensity sensors

An amplitude-phase-conversion self-referencing technique for intensity-modulated photonic sensors that uses two different-wavelength fiber Bragg gratings is presented. With this technique, the system response has been demonstrated to be almost unafffected by network power variations as high as 90% of the total power launched by the source. We prove the multiplexing capability of this type of self-referenced fiber sensor by wavelength-division multiplexing two of them in a star network. A tunable fused biconical wavelength-division multiplexer is used for sensor addressing at the detection block, providing both good isolation and low cross-talk values.

Demodulation scheme for fiber bragg grating sensors based on active control of the spectral response of a wavelength division multiplexer

We present a closed-loop technique for measuring wavelength shifts associated with fiber Bragg gratings by using a fused biconical wavelength division multiplexer (WDM). The spectral response of the WDM is actively tuned by stretching of the coupling region to maintain a fixed coupling ratio at the reflected Bragg wavelength. The closed-loop operation allows sensitivities usually associated with a highly selective WDM to be obtained without compromising the measurement range. A simple theoretical model is presented together with experimental results for temperature and strain measurements.

Cavity dumping of fiber lasers by phase-modulated optical loop mirrors

We report the generation of high-repetition-rate pulses from an erbium-doped fiber laser with a phase-driven optical loop mirror as a cavity dumper. The result demonstrates the potential of this novel method for efficient and ultrafast cavity dumping of fiber lasers.