Cryostat Microtomy of Lung Tissue in an Expanded State

A technique is reported for cryostat sectioning of lung tissue in an expanded state for use in viral immunofluorescence studies. A 1: 2 mixture of O.C.T. embedding compound and phosphate-buffered saline is injected intratracheally into fresh lung tissne. The lung tissue is frozen in liquid nitrogen and sectioned with a cryostat. Compared to other published reports of lung sectioning for immunofluorescence miscroscopy, this method has the advantages of bekg easy and quick, maintaining the lung sectiom in an expanded rather than collapsed state and avoiding contact with chemicals potentially capable of altering sensitive viral antigens.     

Fungal-mediated lung allergic airway disease: The critical role of macrophages and dendritic cells

Fungi are abundant in the environment, causing our lungs to be constantly exposed to a diverse range of species. While the majority of these are cleared effectively in healthy individuals, constant exposure to spores (especially Aspergillus spp.) can lead to the development of allergic inflammation that underpins and worsen diseases such as asthma. Despite this, the precise mechanisms that underpin the development of fungal allergic disease are poorly understood. Innate immune cells, such as macrophages (MΦs) and dendritic cells (DCs), have been shown to be critical for mediating allergic inflammation to a range of different allergens. This review will focus on the crucial role of MΦ and DCs in mediating antifungal immunity, evaluating how these immune cells mediate allergic inflammation within the context of the lung environment. Ultimately, we aim to highlight important future research questions that will lead to novel therapeutic strategies for fungal allergic diseases.     

Epidemic management and control through risk-dependent individual contact interventions

Testing, contact tracing, and isolation (TTI) is an epidemic management and control approach that is difficult to implement at scale because it relies on manual tracing of contacts. Exposure notification apps have been developed to digitally scale up TTI by harnessing contact data obtained from mobile devices; however, exposure notification apps provide users only with limited binary information when they have been directly exposed to a known infection source. Here we demonstrate a scalable improvement to TTI and exposure notification apps that uses data assimilation (DA) on a contact network. Network DA exploits diverse sources of health data together with the proximity data from mobile devices that exposure notification apps rely upon. It provides users with continuously assessed individual risks of exposure and infection, which can form the basis for targeting individual contact interventions. Simulations of the early COVID-19 epidemic in New York City are used to establish proof-of-concept. In the simulations, network DA identifies up to a factor 2 more infections than contact tracing when both harness the same contact data and diagnostic test data. This remains true even when only a relatively small fraction of the population uses network DA. When a sufficiently large fraction of the population (≳ 75%) uses network DA and complies with individual contact interventions, targeting contact interventions with network DA reduces deaths by up to a factor 4 relative to TTI. Network DA can be implemented by expanding the computational backend of existing exposure notification apps, thus greatly enhancing their capabilities. Implemented at scale, it has the potential to precisely and effectively control future epidemics while minimizing economic disruption.     

Detecting Invasions of Marine Organisms: Kamptozoan Case Histories

Detecting marine invasions can be challenging, especially for lesser-known taxa, and requires (a) thorough field surveys of the region of interest for members of the taxon, (b) systematic analyses to identify all species found, (c) literature searches for the worldwide distribution of these species and for previous records of the taxon in this region, and (d) application of rigorous criteria to assess whether each species found is native or introduced. We carried out these steps in order to detect and document kamptozoan (entoproct) invasions on the American mid-Atlantic coast. We report on the occurrence of two colonial kamptozoans (Barentsia benedeni, Loxosomatoides laevis) in Chesapeake Bay (Maryland and Virginia, USA). On the American Atlantic coast, B. benedeni had previously only been reported from Massachusetts, although this species has a worldwide distribution in bays and harbors. The genus Loxosomatoides had not previously been reported from North America and L. laevis was known only from India. Since the genus Loxosomatoides was very poorly characterized, we briefly review all four of its species, which differ only slightly from each other. We have also synonymized L. japonicum with L. laevis. We did not find any of the kamptozoan species previously recorded in surveys of Chesapeake Bay and the American Atlantic coast. This is the first detailed consideration of anthropogenic influences on kamptozoan distributions, and we emphasize that most kamptozoan species are cryptogenic pending further investigation.     

Tyrosinase Reaction and Subsequent Chitosan Adsorption for Selective Removal of a Contaminant from a Fermentation Recycle Stream

In the industrial production of penicillin V, the phenoxyacetate precursor is added to the fermentor to direct biosynthesis. When used for producing semisynthetic penicillins, the penicillin V is often hydrolyzed to 6-aminopenicillanic acid with the regeneration of the phenoxyacetate precursor. To reduce raw-material as well as waste-disposal costs, it is desirable to recycle the phenoxyacetate precursor. Unfortunately, the recycle stream is generally contaminated by the p-hydroxylated derivative of this precursor. We examined a two-step approach to eliminate this contaminant. In the first step the tyrosinase enzyme was used to selectively convert the p-hydroxyphenoxyacetate contaminant to a reactive intermediate—presumably its quinone. In the second step, the tyrosinase-generated reactive intermediate was allowed to react with and strongly bind to chitosan. In contrast, the phenoxyacetate precursor was neither oxidized by tyrosinase nor bound to chitosan. When concentrated phenoxyacetate solutions were tested, the combination of tyrosinase and chitosan effectively converted low levels of the p-hydroxyphenoxyacetate contaminant and removed its products from solution, while the concentration of the phenoxyacetate precursor was unaffected.