PAH source differentiation between historical MGP and significant urban influences for sediments in San Francisco Bay.

A forensic source evaluation of polycyclic aromatic hydrocarbons (PAHs) in nearshore sediments in San Francisco Bay examined total PAH greater than ambient concentrations in sediments, and potential pyrogenic source relationships with respect to PAH compounds typically associated with point and nonpoint pyrogenic source types, including PAHs potentially associated with historical manufactured gas plant (MGP) operations. Diagnostic source ratio analysis was employed for determination of potential PAH source relationships. A two-model approach indicated distinct potential source signatures, as identified from the distributions of higher PAH concentrations in some sediments. Source characterization was aided by Polytopic Vector Analysis (PVA) and data visualization with t-Distributed Stochastic Neighbor Embedding (t-SNE). Two signatures exhibited pyrogenic character likely consistent with historical MGP sources, and one signature was related to creosote. A distinct and significant source of PAHs to the investigation area sediment consisted of ubiquitous nonpoint and potential unidentified point sources is termed "urban influence".

A novel device for assessing dark adaptation in field settings.

BACKGROUND: Aberrant dark adaptation is common to many ocular diseases and pathophysiological conditions, including vitamin A deficiency, cardiopulmonary diseases, and hypoxia. Scotopic vision and pupillary responsiveness have typically been measured using subjective, time-consuming methods. Existing techniques are particularly challenging for use in developing country settings, where vitamin A deficiency remains a major public health problem. Our aim was design a compact, low cost, and easily operated device to assess dark adaptation in the field. METHODS: The Portable Field Dark Adaptometer (PFDA) incorporates a digital camera, a retinal bleaching flash, and a Ganzfeld light source inside a pair of light-obscuring goggles. After a ~10 min period of dark adaption, the infrared camera digitally records afferent pupillary responses to graded light stimuli (-2.9 to 0.1 log cd/m(2)). We tested this device in a variety of field settings to assess: a) ease of use and b) whether test data could clearly and accurately depict the well-known dose-response relationship between light intensity and pupil contraction. A total of 822 videos were collected. We used an open source video analysis software to measure pupil size in pixel units. Pupillary responsiveness was expressed as the percent change in pupil size from pre- to post-light exposure. Box plots, t test, and multi-level mixed effects linear regression modeling were used to characterize the relationship between light intensity and pupillary response. RESULTS: The PFDA was employed with only minor technical challenges in Bangladesh, Kenya, Zambia, and Peru. Our data show a clear linear increase in pupillary constriction with increasing log light intensity. Light intensity was a strong predictor of pupillary response, regardless of baseline pupil size. CONCLUSIONS: The consistent physiological response demonstrated here supports the use of the PFDA as a reliable tool to measure dark adaptation. As a next step, PFDA measurements will be validated against biochemical indicators of vitamin A status and hypoxemia. Ultimately, this new technology may provide a novel approach for nutritional assessment, with potential clinical applications.

OCT Angiography of Paracentral Acute Middle Maculopathy Associated With Central Retinal Artery Occlusion and Deep Capillary Ischemia.

An 82-year-old man presented with acute, painless vision loss in the left eye associated with headaches, jaw claudication, and scalp tenderness. Clinical examination and fluorescein angiography confirmed the diagnosis of a central retinal artery occlusion of the left eye. Spectral-domain optical coherence tomography (OCT) of the left eye showed paracentral acute middle maculopathy (PAMM), and OCT angiography showed severe attenuation of the deep capillary plexus. This is the first case report of OCT angiography of PAMM associated with central retinal artery occlusion confirming the presence of ischemia of the deep retinal capillary plexus.

Primary intraocular (retinal) lymphoma after ocular toxoplasmosis.

PURPOSE: Toxoplasmosis gondii is a common worldwide parasite that presents in the eye with focal retinochoriditis and vitritis. Although it is rare, ocular toxoplasmosis has been linked to primary intraocular (retinal) lymphoma, which is mostly a diffuse large B-cell lymphoma. METHODS: An elderly female patient was treated for recurrent ocular toxoplasmosis, and because of progressive vitritis, a diagnostic vitrectomy was performed. Shortly afterward, she developed multiple brain lesions. Pathologic examinations of the vitreous specimen and cerebral tissues were conducted, including tests for T. gondii, Epstein-Barr virus, and cytomegalovirus DNA. RESULTS: The patient initially responded to antitoxoplasmosis treatment but continued to have persistent vitritis. She was diagnosed with primary intraocular lymphoma, and a repeated magnetic resonance imaging revealed cerebral lesions. Brain biopsy confirmed lymphoma. T. gondii DNA was found in malignant vitreous cells but was absent in the nonmalignant vitreous cells and brain lymphoma cells. The cytomegalovirus and Epstein-Barr virus genes were not found in any of the lymphoma cells. CONCLUSION: T. gondii may have played a role in lymphoproliferation and primary intraocular lymphoma development.

Calcineurin controls growth, morphology, and pathogenicity in Aspergillus fumigatus.

Calcineurin is implicated in a myriad of human diseases as well as homeostasis and virulence in several major human pathogenic microorganisms. The fungus Aspergillus fumigatus is a leading cause of infectious death in the rapidly expanding immunocompromised patient population. Current antifungal treatments for invasive aspergillosis are often ineffective, and novel therapeutic approaches are urgently needed. We demonstrate that a mutant of A. fumigatus lacking the calcineurin A (cnaA) catalytic subunit exhibited defective hyphal morphology related to apical extension and polarized growth, which resulted in drastically decreased filamentation. The delta cnaA mutant lacked the extensive lattice of invading hyphae seen with the wild-type and complemented strains. Sporulation was also affected in the delta cnaA mutant, including morphological conidial defects with the absence of surface rodlets and the added presence of disjunctors creating long conidial chains. Infection with the delta cnaA mutant in several distinct animal models with different types of immunosuppression and inoculum delivery led to a profound attenuation of pathogenicity compared to infection with the wild-type and complemented strains. Lung tissue from animals infected with the delta cnaA mutant showed a complete absence of hyphae, in contrast to tissue from animals infected with the wild-type and complemented strains. Quantitative fungal burden and pulmonary infarct scoring confirmed these findings. Our results support the clinical observation that substantially decreasing fungal growth can prevent disease establishment and decrease mortality. Our findings reveal that calcineurin appears to play a globally conserved role in the virulence of several pathogenic fungi and yet plays specialized roles in each and can be an excellent target for therapeutic intervention.