The Beneficial Fungus Mortierella hyalina Modulates Amino Acid Homeostasis in Arabidopsis under Nitrogen Starvation.

Non-mycorrhizal but beneficial fungi often mitigate (a)biotic stress-related traits in host plants. The underlying molecular mechanisms are mostly still unknown, as in the interaction between the endophytic growth-promoting soil fungus Mortierella hyalina and Arabidopsis thaliana. Here, abiotic stress in the form of nitrogen (N) deficiency was used to investigate the effects of the fungus on colonized plants. In particular, the hypothesis was investigated that fungal infection could influence N deficiency via an interaction with the high-affinity nitrate transporter NRT2.4, which is induced by N deficiency. For this purpose, Arabidopsis wild-type nrt2.4 knock-out and NRT2.4 reporter lines were grown on media with different nitrate concentrations with or without M. hyalina colonization. We used chemical analysis methods to determine the amino acids and phytohormones. Experimental evidence suggests that the fungus does not modulate NRT2.4 expression under N starvation. Instead, M. hyalina alleviates N starvation in other ways: The fungus supplies nitrogen (15N) to the N-starved plant. The presence of the fungus restores the plants' amino acid homeostasis, which was out of balance due to N deficiency, and causes a strong accumulation of branched-chain amino acids. We conclude that the plant does not need to invest in defense and resources for growth are maintained, which in turn benefits the fungus, suggesting that this interaction should be considered a mutualistic symbiosis.

An unusual case of tuberculous optic neuropathy associated with choroiditis.

Tuberculous optic neuropathy that includes papillitis, neuroretinitis, and optic nerve tubercle is a rare presentation of ocular tuberculosis. Though contagious spread from choroid following the hematogenous dissemination of the bacilli has been implicated in the optic nerve involvement, unlike neuroretinitis, optic nerve and choroidal involvement are usually considered as two separate clinical entities. We report a case of optic nerve involvement in a 33-year-old male who had concurrent choroidal involvement at present and also in the past. A strong history of contact with patients of pulmonary tuberculosis, positive tuberculin skin test, interferon gamma release assay, and high-resolution computed tomography helped us to clinch the diagnosis. Patients responded to systemic corticosteroid therapy and anti-tuberculosis treatment. Choroidal involvement in a case of inflammatory optic neuropathy should arise suspicion of tuberculous etiology.

A case of human leukocyte antigen B-27-associated ocular hypotony successfully treated with golimumab.

A 42-year-old male presented to us after an episode of acute anterior human leukocyte antigen (HLA)-B27-associated uveitis, and intraocular pressure (IOP) in the right eye was 4 mmHg. Ultrasound biomicroscopy revealed ciliary body edema with supraciliary effusion. He was on a frequent topical corticosteroid, and oral steroid in addition to receiving a periocular injection depot corticosteroid 20 days back. He was started on treatment with subcutaneous golimumab (GLM). After a month, his IOP in the right eye was 14 mm of Hg with UBM showing resolution of ciliary body edema. GLM can be useful in the management of steroid-resistant cases of HLA B-27-associated ocular hypotony.

Retinal Vasculitis in a Patient with Ankylosing Spondylitis: A rare Association.

PURPOSE: To report a case of retinal vasculitis in a patient with ankylosing spondylitis. BACKGROUND: Posterior segment involvement in HLA B-27-associated uveitis is uncommon but we report a case wherein retinal vasculitis was associated with HLA-B 27 uveitis. CASE: A 36-year-old male, a diagnosed case of ankylosing spondylitis, presented to us with severe anterior segment inflammation associated vitritis in both the eyes. He received topical, oral steroid and immunosuppressive and 3½-month after the control of his uveitis, he underwent cataract surgery in his left eye. Fundus evaluation following cataract surgery revealed sclerosed retinal vessels and wide-field fundus fluorescein angiography confirmed retinal vascular involvement in both the eyes. CONCLUSION: Retinal vasculitis, though rare can occur in patients with ankylosing spondylitis especially in conditions which present with panuveitis-like picture.

A carbon nanotube based x-ray detector.

X-ray detectors based on metal-oxide semiconductor field effect transistors couple instantaneous measurement with high accuracy. However, they only have a limited measurement lifetime because they undergo permanent degradation due to x-ray beam exposure. A field effect transistor based on carbon nanotubes (CNTs), however, overcomes this drawback of permanent degradation, because it can be reset into its starting state after being exposed to the x-ray beam. In this work the CNTs were deposited using a dielectrophoresis method on SiO2 coated p-type (boron-doped) Si substrates. For the prepared devices a best gate voltage shift of 244 V Gy-1 and a source-drain current sensitivity of 382 nA Gy-1 were achieved. These values are larger than those reached by the currently used MOSFET based devices.

Bio-functionalization of multi-walled carbon nanotubes.

Here we present a hybrid approach to functionalize multi-walled carbon nanotubes in aqueous solution, exploring a non-covalent binding strategy. We focus on formation of hybrid complexes consisting of carbon nanotubes decorated by single stranded DNA, non-covalently attached using surfactants as intermediate layers. Unlike single walled carbon nanotubes, revealing easy side wall wrapping of DNA, we observe that wrapping of nucleic acids around multi-walled carbon nanotubes is diameter dependent.