A case of intracranial molluscum contagiosum virus infection diagnosed by metagenomic sequencing of cerebrospinal fluid.

Molluscum contagiosum is a common, self-limiting infectious disease of the skin caused by molluscum contagiosum virus (MCV). The disease primarily affects children, sexually active adults, and immunocompromised individuals. Transmission of the virus occurs by direct skin contact. Therefore, the virus is usually detected in the skin and genitals of patients. However, the diagnosis of intracranial infection by the virus is difficult if the skin/mucosa lessons are atypical or absent, and the presence of the virus in the cerebrospinal fluid has not been reported. We report a very rare case of intracranial infection by molluscum contagiosum virus. A 25-year-old girl was admitted to our hospital due to severe headache but no fever or other symptoms. Upon examination, some small flesh-colored flattened papules on both arms were noticed. Blood tests showed slightly reduced levels of CD3 and CD4 T lymphocytes. Three-dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA) and head magnetic resonance (MR) were both normal. Lumbar puncture was performed, and metagenomic sequencing was applied to the spinal fluid. The unique sequences of the molluscum contagiosum virus were identified in the fluid. The patient was then diagnosed with intracranial molluscum contagiosum virus infection. No special treatment was given. The headache gradually disappeared, and the patient was discharged. During our quarterly follow-up, the girl appeared normal, and her skin lesions disappeared. However, her CD3 and CD4 T lymphocyte counts were still slightly lower than the normal level. Our case shows that the application of metagenomic sequencing to cerebrospinal fluid is a sensitive and powerful means to detect pathogens causing intracranial infection. Keywords: Molluscum contagiosum; intracranial infection; metagenomics sequencing.

Broadband and efficient plasmonic control in the near-infrared and visible via strong interference of surface plasmon polaritons.

Broadband and tunable control of surface plasmon polaritons in the near-infrared and visible spectrum is demonstrated theoretically and numerically with a pair of phased nanoslits. We establish, with simulations supported by a coupled wave model, that by dividing the incident power equally between two input channels, the maximum plasmon intensity deliverable to either side of the nanoslit pair is twice that for an isolated slit. For a broadband source, a compact device with nanoslit separation of the order of a tenth of the wavelength is shown to steer nearly all the generated plasmons to one side for the same phase delay, thereby achieving a broadband unidirectional plasmon launcher. The reported effect can be applied to the design of ultra-broadband and efficient tunable plasmonic devices.

Dynamic beam steering from a subwavelength slit by selective excitation of guided modes.

Dynamic control of the direction of radiation of the light emanating from a subwavelength slit carved out of a thin metal film is experimentally demonstrated. This is achieved by selective excitation of the individual guided modes in the slit by setting the phase of three coherent laser beams. By changing the voltage across a piezoelement, we obtain unprecedented directional steering, without relying on any mechanical alignment of optical elements. The angular range over which this maximum can be swept is determined by the intensity setting of one of the incident beams. Through simulations, we show that this method can also be applied to steer the radiation from a square hole in two independent directions. Our method can be applied to create a directional nanoemitter which can selectively address one or more detectors, or as an optical switch in photonic circuits.

Plasmon switching: observation of dynamic surface plasmon steering by selective mode excitation in a sub-wavelength slit.

We report a plasmon steering method that enables us to dynamically control the direction of surface plasmons generated by a two-mode slit in a thin metal film. By varying the phase between different coherent beams that are incident on the slit, individual waveguide modes are excited. Different linear combinations of the two modes lead to different diffracted fields at the exit of the slit. As a result, the direction in which surface plasmons are launched can be controlled. Experiments confirm that it is possible to distribute an approximately constant surface plasmon intensity in any desired proportion over the two launching directions. We also find that the anti-symmetric mode generates surface plasmons more efficiently than the fundamental symmetric mode.

Well-confined surface plasmon polaritons for sensing applications in the near-infrared.

The surface plasmon polariton (SPP) dispersion at the interface between a dielectric half-space and a layered metallodielectric metamaterial is investigated. By varying the material constituants, it is shown that the SPP resonance frequency can be readily shifted to the near-IR. Through numerical simulations, the validity domain of homogenization and the effects of the finite number of layers in the metamaterial are studied. It is found that as few as N=2 periods are sufficient for practical operation. These results reveal the potential of employing metallodielectric stacks for sensing applications in the near-IR regime.

Molecular Evidence of Genome Editing in a Mouse Model of Immunodeficiency.

Genome editing is the introduction of directed modifications in the genome, a process boosted to therapeutic levels by designer nucleases. Building on the experience of ex vivo gene therapy for severe combined immunodeficiencies, it is likely that genome editing of haematopoietic stem/progenitor cells (HSPC) for correction of inherited blood diseases will be an early clinical application. We show molecular evidence of gene correction in a mouse model of primary immunodeficiency. In vitro experiments in DNA-dependent protein kinase catalytic subunit severe combined immunodeficiency (Prkdc scid) fibroblasts using designed zinc finger nucleases (ZFN) and a repair template demonstrated molecular and functional correction of the defect. Following transplantation of ex vivo gene-edited Prkdc scid HSPC, some of the recipient animals carried the expected genomic signature of ZFN-driven gene correction. In some primary and secondary transplant recipients we detected double-positive CD4/CD8 T-cells in thymus and single-positive T-cells in blood, but no other evidence of immune reconstitution. However, the leakiness of this model is a confounding factor for the interpretation of the possible T-cell reconstitution. Our results provide support for the feasibility of rescuing inherited blood disease by ex vivo genome editing followed by transplantation, and highlight some of the challenges.

Nipah virus infection of pigs in peninsular Malaysia.

Between late 1998 and 1999, the spread of a new disease of pigs, characterized by a pronounced respiratory and neurological syndrome, sometimes accompanied by the sudden death of sows and boars, was recorded in pig farms in peninsular Malaysia. The disease appeared to have a close association with an epidemic of viral encephalitis among workers on pig farms. A previously unrecognised paramyxovirus was later identified from this outbreak; this virus was related to, but distinct from, the Hendra virus discovered in Australia in 1994. The new virus was named 'Nipah' and was confirmed by molecular characterization to be the agent responsible for the disease in both humans and pigs. The name proposed for the new pig disease was 'porcine respiratory and neurological syndrome' (also known as 'porcine respiratory and encephalitis syndrome'), or, in peninsular Malaysia, 'barking pig syndrome'. The authors describe the new disease and provide the epidemiological findings recorded among infected pigs. In addition, the control programmes which were instituted to contain the virus in the national swine herd are outlined.

Reefs and islands of the Chagos Archipelago, Indian Ocean: why it is the world's largest no-take marine protected area.

The Chagos Archipelago was designated a no-take marine protected area (MPA) in 2010; it covers 550 000 km2, with more than 60 000 km2 shallow limestone platform and reefs. This has doubled the global cover of such MPAs.It contains 25-50% of the Indian Ocean reef area remaining in excellent condition, as well as the world's largest contiguous undamaged reef area. It has suffered from warming episodes, but after the most severe mortality event of 1998, coral cover was restored after 10 years.Coral reef fishes are orders of magnitude more abundant than in other Indian Ocean locations, regardless of whether the latter are fished or protected.Coral diseases are extremely low, and no invasive marine species are known.Genetically, Chagos marine species are part of the Western Indian Ocean, and Chagos serves as a 'stepping-stone' in the ocean.The no-take MPA extends to the 200 nm boundary, and. includes 86 unfished seamounts and 243 deep knolls as well as encompassing important pelagic species.On the larger islands, native plants, coconut crabs, bird and turtle colonies were largely destroyed in plantation times, but several smaller islands are in relatively undamaged state.There are now 10 'important bird areas', coconut crab density is high and numbers of green and hawksbill turtles are recovering.Diego Garcia atoll contains a military facility; this atoll contains one Ramsar site and several 'strict nature reserves'. Pollutant monitoring shows it to be the least polluted inhabited atoll in the world. Today, strict environmental regulations are enforced.Shoreline erosion is significant in many places. Its economic cost in the inhabited part of Diego Garcia is very high, but all islands are vulnerable.Chagos is ideally situated for several monitoring programmes, and use is increasingly being made of the archipelago for this purpose.