Immunodiagnosis of Neurocysticercosis: Ways to Focus on the Challenge

Neurocysticercosis (NCC) is a disease of the central nervous system that is considered a public health problem in endemic areas. The definitive diagnosis of this disease is made using a combination of tools that include imaging of the brain and immunodiagnostic tests, but the facilities for performing them are usually not available in endemic areas. The immunodiagnosis of NCC is a useful tool that can provide important information on whether a patient is infected or not, but it presents many drawbacks as not all infected patients can be detected. These tests rely on purified or semipurified antigens that are sometimes difficult to prepare. Recent efforts have focused on the production of recombinant or synthetic antigens for the immunodiagnosis of NCC and interesting studies propose the use of new elements as nanobodies for diagnostic purposes. However, an immunodiagnostic test that can be considered as “gold standard” has not been developed so far. The complex nature of cysticercotic disease and the simplicity of common immunological assumptions involved explain the low scores and reproducibility of immunotests in the diagnosis of NCC. Here, the most important efforts for developing an immunodiagnostic test of NCC are listed and discussed. A more punctilious strategy based on the design of panels of confirmed positive and negative samples, the use of blind tests, and a worldwide effort is proposed in order to develop an immunodiagnostic test that can provide comparable results. The identification of a set of specific and representative antigens of T. solium and a thorough compilation of the many forms of antibody response of humans to the many forms of T. solium disease are also stressed as necessary

Klebsiella pneumoniae Strains Producing Extended-Spectrum B-Lactamases in Spain: Microbiological and Clinical Features

Extended-spectrum B-lactamases (ESBL) of the CTX-M, SHV, and TEM families were recognized in 76 (67%), 31 (27%), and 6 (5%) isolates, respectively, among 162 ESBL-producing Klebsiella pneumoniae (ESBLKp) strains obtained in a multicenter study in Spain. Predisposing factors for ESBL-Kp acquisition included invasive procedures, mechanical ventilation, and previous antimicrobial use

Experimental study of MMI structures in a switchable continuous-wave thulium-doped all-fiber laser

Switchable multi-wavelength laser emission from a thulium-doped all-fiber laser is reported by implementing a tapered and a non-tapered multi-modal interference (MMI) filters. The MMI structure relies on a coreless optical fiber spliced in between two single-mode optical fibers. For the non-tapered case, a minimum insertion loss of 12.60 dB is achieved around the 2-μm region, from which stable generation of commutable dual-wavelength emission at 1986.34 nm and 2017.38 nm is obtained. On the other hand, the tapered MMI structure performs a minimum insertion loss of 8.74 dB at the 2-μm region, allowing a stable triple-wavelength emission at 1995.4 nm, 2013.3 nm, and 2038.3 nm. In addition, commutable dual-wavelength emission was also obtained at 1997.9 nm and 2032.1 nm. The generated laser lines perform bandwidths of around 50 pm, low peak spectral power fluctuations and signal-to-noise ratio of 50 dB

PATRONES DE LA MACROFAUNA EDAFICA EN UN CULTIVO DE ZEA MAIZ DURANTE LA FASE POSTCOSECHA EN LA MANCHA, VERACRUZ, MEXICO

The soil macrofauna of a cornfield was studied during the fallow period in El Centro de Investigaciones Costeras "La Mancha", Veracruz. Patterns of soil macrofauna density, spatial distribution and diversity were described and their relationships with soil temperature, moisture, organic matter and pH were explored. Four strategies were combined to undertake this aim: a) sampling of soil macrofauna was carried out in seven ten cm soil layers from 0 to 70 cm depth; b) soil macrofauna was identified to morphospecies level; c) the size of morphospecies aggregations was determined following a the two-term local quadrat variance method (TTLQV); d) analysis of canonical correspondence was used to arrange morphospecies distribution in an spatial and environmental framework of reference. Density of soil macrofauna in the studied site seems to be the lowest value ever recorded in similar studies (246 individuals m-2). Forty-six morphospecies were collected that are mainly distributed in the top 20 cm soil layer and present an aggregated horizontal pattern of distribution. The diameter of aggregations of Oligochaeta juveniles, larvae of Tenebrionidae and Diplopoda juveniles was >1.5m, 0.9 m and 1.2 m respectively. It was possible to arrange different groups of soil Macrofauna according with their ranges of tolerance to environmental variables. Therefore, it is suggested that these patterns do reflect preferences of soil biota to microenvironments and do respond to soil degradation.Estudiamos la macrofauna del suelo de un cultivo de Zea maiz durante la fase postcosecha en el Centro de Investigaciones Costeras La Mancha, Veracruz. Describimos patrones de densidad, distribución espacial y diversidad en relación con la temperatura, humedad y pH del suelo. Para esto conjuntamos cuatro estrategias: a) muestreamos la macrofauna en estratos de 10 cm hasta los 70 cm de profundidad; b) separamos la fauna a nivel de morfoespecie; c) estimamos el tamaño de las agregaciones de las morfoespecies mediante una técnica de cuadrante-varianza; y d) ordenamos, mediante un análisis de correspondencia canónica, morfoespecies y estratos en un marco de referencia ambiental. La densidad de la macrofauna del suelo estudiado es la más baja reportada hasta la fecha para agroecosistemas en el mundo (246 individuos/m2). Colectamos 46 morfoespecies, que se distribuyeron generalmente en el primer o segundo estrato del suelo y presentaron una distribución agregada. El diametro de las agregaciones de los Oligochaeta juveniles fue superior a 1.5 m y para las larvas de Tenebrionidae y los Diplopoda juveniles fue de 0.9 y 1.2 m, respectivamente. Debido a que es posible separar distintos grupos de acuerdo con sus rangos de tolerancia a la temperatura, pH, humedad y materia orgánica en el suelo, es factible que los patrones de distribución registrados sean un reflejo de las preferencias de la biota a diferentes microambientes y al estado de degradación del suelo

Experimental study of an in-fiber acousto-optic tunable bandpass filter for single- and dual-wavelength operation in a thulium-doped fiber laser

A tunable single- and dual-wavelength thulium-doped all-fiber laser is demonstrated based on the implementation of an in-fiber acousto-optic tunable bandpass filter (AOTBF). The AOTBF is fabricated to be operated in the 1.9 µm region, and takes advantage of the intermodal coupling effect produced by traveling flexural acoustic waves in an optical fiber. It exhibits a 3-dB bandwidth of 2.04 nm with an insertion loss of 4.75 dB. The tuning properties of the AO device allows a continuous-wave operation with characteristics of wide tuning range (211.5 nm), narrow linewidth (50 pm) and high signal-to-noise ratio (60 dB). In the dual-wavelength regime, the laser is capable of independent tuning of each of the laser lines, achieving a tunable dual-wavelength emission that extends from 1802.67 to 1932.75 nm. A controllable wavelength spacing with minimum and maximum separations of 1.04 and 130.08 nm is obtained

Broadband tuning of a long-cavity all-fiber mode locked Thulium-doped fiber laser using an acousto-optic bandpass filter

A long-cavity passively mode-locked thulium-doped all-fiber laser is reported incorporating a tapered acousto-optic tunable bandpass filter (AOTBF). The operation of the AOTBF relies on the intermodal coupling between core and cladding modes when a flexural acoustic wave propagates along an 80-microm tapered fiber. The filter works in transmission and exhibits a 3-dB bandwidth of 9.02 nm with an insertion loss of 3.4 dB. The laser supports ultrashort pulse generation at a low repetition rate of 784.93 kHz. Optical pulses with 2.43 nm of optical bandwidth and 2.1 ps pulse duration were obtained in a broad tuning range from 1824.77 to 1905.16 nm

Q switching and mode locking pulse generation from an all-fiber ring laser by intermodal acousto-optic bandpass modulation

Q-switched and mode-locked (QML) pulse generation from an all-fiber ring laser based on intermodal acousto-optic bandpass modulation is reported. The modulator relies on full-acousto-optic mode re-coupling cycle induced by a standing flexural acoustic wave, with a transmission response that is controlled by amplitude modulation of the acoustic wave signal. The Q factor of the cavity is controlled by a rectangular pulse wave with variable frequency and duty cycle, whereas mode locking is achieved by amplitude modulation derived from a standing flexural acoustic wave. The best QML pulses were obtained at 0.5 kHz repetition rate, with a pump power of 549.2 mW, at the optical wavelength of 1568.2 nm. A maximum overall energy of 2.14 µJ at an average output power of 1.07 mW was achieved, corresponding to a burst of mode-locked sub-pulses of 100 ps pulse duration within a QML envelope of 3.5 µs

Interaction of PLP with GFP-MAL2 in the Human Oligodendroglial Cell Line HOG

The velocity of the nerve impulse conduction of vertebrates relies on the myelin sheath, an electrically insulating layer that surrounds axons in both the central and peripheral nervous systems, enabling saltatory conduction of the action potential. Oligodendrocytes are the myelin-producing glial cells in the central nervous system. A deeper understanding of the molecular basis of myelination and, specifically, of the transport of myelin proteins, will contribute to the search of the aetiology of many dysmyelinating and demyelinating diseases, including multiple sclerosis. Recent investigations suggest that proteolipid protein (PLP), the major myelin protein, could reach myelin sheath by an indirect transport pathway, that is, a transcytotic route via the plasma membrane of the cell body. If PLP transport relies on a transcytotic process, it is reasonable to consider that this myelin protein could be associated with MAL2, a raft protein essential for transcytosis. In this study, carried out with the human oligodendrocytic cell line HOG, we show that PLP colocalized with green fluorescent protein (GFP)-MAL2 after internalization from the plasma membrane. In addition, both immunoprecipitation and immunofluorescence assays, indicated the existence of an interaction between GFP-MAL2 and PLP. Finally, ultrastructural studies demonstrated colocalization of GFP-MAL2 and PLP in vesicles and tubulovesicular structures. Taken together, these results prove for the first time the interaction of PLP and MAL2 in oligodendrocytic cells, supporting the transcytotic model of PLP transport previously suggested