Most microbes have not been cultured, and many of those that are cultivatable are difficult, dangerous or expensive to propagate or are genetically intractable. Routine cloning of large genome fractions or whole genomes from these organisms would significantly enhance their discovery and genetic and functional characterization. Here we report the cloning of whole bacterial genomes in the yeast Saccharomyces cerevisiae as single-DNA molecules. We cloned the genomes of Mycoplasma genitalium (0.6 Mb), M. pneumoniae (0.8 Mb) and M. mycoides subspecies capri (1.1 Mb) as yeast circular centromeric plasmids. These genomes appear to be stably maintained in a host that has efficient, well-established methods for DNA manipulation.
Background
Cancer-associated retinopathy (CAR) is associated with various malignancies, including small cell lung cancer (SCLC). It is difficult to recognize, but prompt diagnosis is crucial for the patient, as retinopathy may be a herald sign that precedes systemic manifestations by months, thus allowing early treatment of the underlying malignancy.
Case presentation
We present a rare case of CAR with chorioretinitis and optic neuritis in a patient with occult SCLC. The patient presented with rapidly progressive peripheral field loss and photopsias with “prism-like” visual disturbances. Her symptoms stabilized with intravenous methylprednisolone, and her cancer was treated with carboplatin, etoposide and radiotherapy.
Conclusions
This is the first reported case of SCLC-associated CAR to present with chorioretinitis. CAR can be a herald feature of SCLC, and early recognition of the disease should prompt a systemic evaluation for an occult malignancy, which may be critical for patient survival. Further understanding of CAR pathogenesis may offer potential avenues for treatment.
Recently developed anti-tumour therapies targeting immune checkpoints include tremelimumab and durvalumab. These agents have incompletely characterised side effect profiles. The authors report a 68-year-old man treated for non-small cell lung cancer (NSCLC) with a combination of tremelimumab and durvalumab. After treatment he developed diplopia, ptosis, fatigue, weakness, and an inflammatory myopathy affecting the extraocular muscles requiring hospitalisation. Electromyography (EMG) testing and muscle biopsy suggested inflammatory myopathy without sign of myasthenia. Within 1 month of withdrawal of cancer therapies and initiation of oral steroid therapy, ocular and systemic symptoms had resolved. This notable adverse effect has not been previously described for these drugs administered singly or in combination, and ophthalmologists should be aware of this presentation in patients treated with these agents.
Orbital AA amyloidosis can induce a local inflammatory response, manifesting as orbital swelling, papillitis, posterior scleritis, choroiditis, and exudative retinal detachment. Choriocapillaris vasoocclusion with reactive inflammation to the presence of amyloid fibrils likely underlies this presentation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.