Sin Nombre virus prevalence from 2014-2017 in wild deer mice, Peromyscus maniculatus, on five of the California Channel Islands

Sin Nombre virus (SNV) is a zoonotic virus that is highly pathogenic to humans. The deer mouse, Peromyscus maniculatus, is the primary host of SNV, and SNV prevalence in P. maniculatus is an important indicator of human disease risk. Because the California Channel Islands contain permanent human settlements, receive hundreds of thousands of visitors each year, and can have extremely high densities of P. maniculatus, surveillance for SNV in island P. maniculatus is important for understanding the human risk of zoonotic disease. Despite the importance of surveillance on these heavily utilized islands, SNV prevalence (i.e. the proportion of P. maniculatus that test positive to antibodies to SNV) has not been examined in the last 13-27 years. We present data on 1,610 mice sampled for four consecutive years (2014-2017) on five of the California Channel Islands: East Anacapa, Santa Barbara, Santa Catalina, San Nicolas, and San Clemente. Despite historical data indicating SNV-positive mice on San Clemente and Santa Catalina, we detected no SNV-positive mice on these islands, suggesting very low prevalence or possible loss of SNV. Islands historically free of SNV (East Anacapa, Santa Barbara, and San Nicolas) remained free of SNV, suggesting that rates of pathogen introduction from other islands and/or the mainland are low. Although continued surveillance is warranted to determine whether SNV establishes on these islands, our work helps inform current human disease risk in these locations and suggests that SNV prevalence on these islands is currently very low.

Tuning porosity in macroscopic monolithic metal-organic frameworks for exceptional natural gas storage

Widespread access to greener energy is required in order to mitigate the effects of climate change. A significant barrier to cleaner natural gas usage lies in the safety/efficiency limitations of storage technology. Despite highly porous metal-organic frameworks (MOFs) demonstrating record-breaking gas-storage capacities, their conventionally powdered morphology renders them non-viable. Traditional powder shaping utilising high pressure or chemical binders collapses porosity or creates low-density structures with reduced volumetric adsorption capacity. Here, we report the engineering of one of the most stable MOFs, Zr-UiO-66, without applying pressure or binders. The process yields centimetre-sized monoliths, displaying high microporosity and bulk density. We report the inclusion of variable, narrow mesopore volumes to the monoliths’ macrostructure and use this to optimise the pore-size distribution for gas uptake. The optimised mixed meso/microporous monoliths demonstrate Type II adsorption isotherms to achieve benchmark volumetric working capacities for methane and carbon dioxide. This represents a critical advance in the design of air-stable, conformed MOFs for commercial gas storage.

While metal–organic frameworks exhibit record-breaking gas storage capacities, their typically powdered form hinders their industrial applicability. Here, the authors engineer UiO-66 into centimetre-sized monoliths with optimal pore-size distributions, achieving benchmark volumetric working capacities for both CH₄ and CO₂.

Extreme cold consistently reduces seedling growth but has species-specific effects on browse tolerance in summer

PREMISE OF THE STUDY

Extreme weather events can injure plants, causing decreased survival. However, we may underestimate the ecological importance of extreme events if they have strong sublethal effects that manifest after several months. We tested the hypothesis that late-winter extreme-cold events decrease the ability of woody plants to grow and tolerate stem removal in summer.

METHODS

Seedlings from four temperate tree species (Abies balsamea, Pinus resinosa, P. strobus, Quercus rubra) were acclimated to winter conditions in growth chambers, and experienced 1 week of warm temperatures before being exposed to one of three 24-h extreme-cold events (minimum temperature: 8°C control, -8°C, or -16°C). Seedlings were then transferred to a greenhouse where we monitored survival and growth. Three months after the extreme-cold event, we mimicked an herbivore attack by removing either 25% or 75% of new stem growth from seedlings of two species (P. resinosa, Q. rubra).

KEY RESULTS

While extreme cold had no immediate effect on seedling survival, the coldest temperature treatment reduced stem growth 51% relative to controls. Stem removal decreased P. resinosa survival in the -16°C treatment, but stem removal treatment had no effect on P. resinosa survival in the intermediate -8°C treatment or 8°C control. Stem removal did not alter Q. rubra survival.

CONCLUSIONS

Ephemeral late-winter cold temperatures can have unappreciated effects on growing-season seedling dynamics, including growth and herbivory. For predicting how extreme-cold events might alter large-scale patterns of tree distribution, seedlings should be monitored throughout the growing season following extreme late-winter frosts.

Changes in Trap Temperature as a Method to Determine Timing of Capture of Small Mammals

Patterns of animal activity provide important insight into hypotheses in animal behavior, physiological ecology, behavioral ecology, as well as population and community ecology. Understanding patterns of animal activity in field settings is often complicated by the need for expensive equipment and time-intensive methods that limit data collection. Because animals must be active to be detected, the timing of detection (e.g., the timing of capture) may be a useful proxy for estimation of activity time. In this paper, we describe a new method for determining timing of capture for small mammals. In our method, two small temperature loggers are positioned in each trap so that one logger registers the internal temperature of a live-trap at set intervals while the other logger simultaneously records external trap temperature. We illustrate the utility of this technique using field data from live-trapping of deer mice, Peromyscus maniculatus, one of the most ubiquitous, widely distributed small mammals in North America. Traps with animals inside registered consistent increases in internal trap temperature, creating a clear, characteristic temperature deviation between the two data loggers that can determine trap entry time within a very narrow time window (e.g., 10 minutes). We also present pilot data to demonstrate the usefulness of the method for two other small-mammal species. This new method is relatively inexpensive, robust to field conditions, and does not require modification of traps or wiring of new devices. It can be deployed as part of common live-trapping methods, making it possible to assay the timing of capture for a large number of animals in many different ecological contexts. In addition to quantifying timing of capture, this approach may also collect meaningful temperature data and provide insight into the thermal costs of animal activity and relationships between environmental conditions and the time of an animal’s capture.

Mechanism of FGF23 processing in fibrous dysplasia

Fibroblast growth factor-23 (FGF23) is a phosphate- and vitamin D-regulating hormone derived from osteoblasts/osteocytes that circulates in both active (intact, iFGF23) and inactive (C-terminal, cFGF23) forms. O-glycosylation by O-glycosyl transferase N-acetylgalactosaminyltransferase 3 (ppGalNAcT3) and differential cleavage by furin have been shown to be involved in regulating the ratio of active to inactive FGF23. Elevated iFGF23 levels are observed in a number of hypophosphatemic disorders, such as X-linked, autosomal recessive, and autosomal dominant hypophosphatemic rickets, whereas low iFGF23 levels are found in the hyperphosphatemic disorder familial tumoral calcinosis/hyperphosphatemic hyperostosis syndrome. Fibrous dysplasia of bone (FD) is associated with increased total FGF23 levels (cFGF23 + iFGF23); however, classic hypophosphatemic rickets is uncommon. Our results suggest that it can be explained by increased FGF23 cleavage leading to an increase in inactive cFGF23 relative to active iFGF23. Given the fact that FD is caused by activating mutations in the small G-protein G(s) α that results in increased cyclic adenosine monophosphate (cAMP) levels, we postulated that there may be altered FGF23 cleavage in FD and that the mechanism may involve alterations in cAMP levels and ppGalNacT3 and furin activities. Analysis of blood specimens from patients with FD confirmed that the elevated total FGF23 levels are the result of proportionally increased cFGF23 levels, consistent with less glycosylation and enhanced cleavage by furin. Analysis of primary cell lines of normal and mutation-harboring bone marrow stromal cells (BMSCs) from patients with FD demonstrated that BMSCs harboring the causative G(s) α mutation had higher cAMP levels, lower ppGalNAcT3, and higher furin activity. These data support the model wherein glycosylation by ppGalNAcT3 inhibits FGF23 cleavage by furin and suggest that FGF23 processing is a regulated process that controls overall FGF23 activity in FD patients.

Identification of genes differentially expressed in benign prostatic hyperplasia

Differences between benign prostatic hyperplasia (BPH) and normal prostate tissue at the level of mRNA expression provide an opportunity to identify candidate genes for this disease. A cDNA subtraction procedure was used to isolate differentially expressed genes in BPH. The subtraction was done by solution hybridization of BPH cDNA against excess normal prostate cDNA. We identified known, EST, and novel genes by sequence and database analysis of the subtracted cDNAs. Several of these cDNAs were used as probes in Northern blotting analysis to confirm over-expression of their corresponding mRNAs in BPH tissues. One highly upregulated sequence of interest shared identity with a known mRNA encoding human NELL2, a protein containing epidermal growth factor-like domains. NELL2 was not previously reported to be expressed in prostate and may code for a novel prostatic growth factor. In situ hybridization analysis of hyperplastic prostate specimens demonstrated that NELL2 mRNA expression is predominantly localized in basal cells of the epithelium. Disease-related changes in the levels of NELL2 may contribute to alterations in epithelial-stromal homeostasis in BPH. (J Histochem Cytochem 49:669-670, 2001)

Characterization of the human cysteinyl leukotriene CysLT1 receptor

The cysteinyl leukotrienes-leukotriene C4(LTC4), leukotriene D4(LTD4) and leukotriene E4(LTE4)-are important mediators of human bronchial asthma. Pharmacological studies have determined that cysteinyl leukotrienes activate at least two receptors, designated CysLT1 and CysLT2. The CysLT1-selective antagonists, such as montelukast (Singulair), zafirlukast (Accolate) and pranlukast (Onon), are important in the treatment of asthma. Previous biochemical characterization of CysLT1 antagonists and the CysLT1 receptor has been in membrane preparations from tissues enriched for this receptor. Here we report the molecular and pharmacological characterization of the cloned human CysLT1 receptor. We describe the functional activation (calcium mobilization) of this receptor by LTD4 and LTC4, and competition for radiolabelled LTD4 binding to this receptor by the cysteinyl leukotrienes and three structurally distinct classes of CysLT1-receptor antagonists. We detected CysLT1-receptor messenger RNA in spleen, peripheral blood leukocytes and lung. In normal human lung, expression of the CysLT1-receptor mRNA was confined to smooth muscle cells and tissue macrophages. Finally, we mapped the human CysLT1-receptor gene to the X chromosome.

Pathogenesis of experimental Ebola virus infection in guinea pigs

The subtype Zaire of Ebola (EBO) virus (Mayinga strain) was adapted to produce lethal infections in guinea pigs. In many ways, the disease was similar to EBO infections in nonhuman primates and humans. The guinea pig model was used to investigate the pathologic events in EBO infection that lead to death. Analytical methods included immunohistochemistry, in situ hybridization, and electron microscopy. Cells of the mononuclear phagocyte system, primarily macrophages, were identified as the early and sustained targets of EBO virus. During later stages of infection, interstitial fibroblasts in various tissues were infected, and there was evidence of endothelial cell infection and fibrin deposition. The distribution of lesions, hematologic profiles, and increases in serum biochemical enzymes associated with EBO virus infection in guinea pigs was similar to reported findings in experimentally infected nonhuman primates and naturally infected humans.

Pathology of experimental Ebola virus infection in African green monkeys. Involvement of fibroblastic reticular cells

BACKGROUND

Ebola virus has been responsible for explosive lethal outbreaks of hemorrhagic fever in both humans and nonhuman primates. Previous studies showed a predilection of Ebola virus for cells of the mononuclear phagocyte system and endothelial cells.

OBJECTIVE

To examine the distribution of lesions and Ebola virus antigen in the tissues of six adult male African green monkeys (Cercopithecus aethiops) that died 6 to 7 days after intraperitoneal inoculation of Ebola-Zaire (Mayinga) virus.

METHODS

Tissues were examined histologically, immunohistochemically, and ultrastructurally.

RESULTS

A major novel finding of this study was that fibroblastic reticular cells were immunohistochemically and ultrastructurally identified as targets of Ebola virus infection.

CONCLUSIONS

The role of Ebola virus-infected fibroblastic reticular cells in the pathogenesis of Ebola hemorrhagic fever warrants further investigation. This is especially important because of recent observations indicating that fibroblastic reticular cells, along with the reticular fibers they produce, maximize the efficiency of the immune response.

Experimental reproduction of a spiking mortality syndrome of turkeys

Two-day-old turkey poults were inoculated with either a chicken embryo homogenate used previously to produce spiking mortality syndrome in chickens (the "Oakwood Agent") or an intestine-pancreas homogenate collected from field turkeys with the syndrome known as spiking mortality of turkeys. Twelve days postinoculation, the mean plasma insulinlike growth factor-1 (IGF-1) level and mean body weights were significantly depressed, and the mean plasma growth hormone level was significantly elevated, in the poults receiving the turkey-derived homogenate (P < or = 0.0003), as was previously reported in chickens with spiking mortality syndrome. The depression in plasma IGF-1 levels may explain the runting seen in poults that survive spiking mortality of turkeys in the field. Following a 4-hr fast and a brief cool water spraying, poults exhibited clinical signs indistinguishable from those of chicks with spiking mortality syndrome. However, plasma glucose levels in the affected poults were within the normal range, unlike chickens with spiking mortality syndrome. Immunohistochemistry on formalin-fixed intestines, ceca, and bursae produced positive staining using an arenavirus antibody in epithelial cells of poults inoculated with the turkey homogenate and those inoculated with the Oakwood Agent. Tissues of uninoculated controls were negative. Poults inoculated with the Oakwood Agent did not show noticeable disease.

Experimental reproduction of hypoglycemia-spiking mortality syndrome in broiler chickens with the use of homogenized brains containing arenaviruslike particles

Severe hypoglycemia-spiking mortality syndrome was experimentally reproduced in broiler chicks. Inoculum was homogenized brains from 28-day-old commercial broiler chicks with central nervous system signs (50% [v/v] in phosphate-buffered saline with 2% fetal calf serum). Oral inoculations of 1.2 ml of the homogenate were given at 1 day of age to broiler chicks (n = 15). Fourteen days later, chicks were fasted and stressed with a 2-sec cool water spray. Six chicks (40%) developed clinical signs of spiking mortality syndrome and were severely hypoglycemic. Uninoculated control chicks (n = 15) from the same hatch, also fasted and stressed simultaneously, were unaffected. Examination of a banded fraction produced from the inoculum with the use of transmission electron microscopy with negative staining revealed viruslike particles indistinguishable from arenavirus particles stained and examined simultaneously. Avian encephalomyelitis virus was isolated by one of three laboratories attempting virus isolation with the use of embryonating chicken eggs.

Pathology and immunohistochemistry of callitrichid hepatitis, an emerging disease of captive New World primates caused by lymphocytic choriomeningitis virus

Callitrichid hepatitis is an arenavirus infection that recently emerged as a highly fatal disease of New World primates in the Callitrichidae family. As we previously reported, these primates develop hepatitis after contact with mice that are infected with variants of LCMV (LVMCCH), recently determined to have 86% identity with GC-P gene of the Armstrong and Western strains of LCMV. Here, we describe the histopathological lesions and tissue localization of viral antigens in confirmed cases of callitrichid hepatitis from recent outbreaks in two U.S. zoos. The liver in marmosets and tamarins with fatal infections consistently showed degeneration, necrosis, and inflammation, with variable involvement of the spleen, lymph nodes, adrenal glands, intestine, pancreas, and central nervous system. Lymphocytic choriomeningitis virus antigens were identified immunohistochemically in necrotic foci in these organs as well as in nondegenerating areas in lungs, kidney, urinary bladder, brain, and testes. The multi-organ tropism and histological pattern of LCMV infection in marmosets and tamarins are similar to those reported for the highly virulent arenavirus that causes Lassa fever in humans. Comparative studies of callitrichid hepatitis and Lassa fever would therefore be mutually beneficial for human and nonhuman primate medicine.

Pathogenesis of Pichinde virus infection in strain 13 guinea pigs: an immunocytochemical, virologic, and clinical chemistry study

Pichinde virus has been adapted to produce lethal infection of Strain 13 guinea pigs. Viral replication and presence of viral antigen in frozen tissues stained by immunofluorescence has been previously described. Further investigation into the pathogenesis of this disease has been hampered by the lack of a light microscopic method for correlating histologic lesions and the presence of Pichinde viral antigens. For this purpose, we developed a sensitive immunocytochemical technique for staining Pichinde viral antigens in formalin-fixed, paraffin-embedded tissue. Enhancement of the immunocytochemical staining with nickel chloride markedly improved detection of viral antigens. We examined frozen and formalin-fixed tissues from Strain 13 guinea pigs for viral antigens by light microscopy and immunocytochemistry at various intervals after infection with Pichinde virus. Progressive involvement of different tissues correlated with organ injury measured by serum biochemical abnormalities. Pichinde viral antigen was first detected in splenic macrophages five days after infection and their subsequent destruction facilitated persistent viremia. The inability to clear virus led to multiple organ infection and vascular involvement. Ensuing infections involved particularly the liver, spleen, adrenal glands, lungs, and intestines. Gastroenteritis developed, with extensive involvement of the muscularis mucosa throughout the gastrointestinal tract. Water and food intake decreased rapidly after day 8, leading to marked weight loss. Fatty changes of the liver suggested metabolic derangement that was further exacerbated terminally by adrenal infection and pulmonary impairment.

Taurine transport in epilepsy

Previous studies of plasma taurine concentrations in epileptics have yielded equivocal results. We measured plasma and urinary taurine in 41 epileptic and 68 control subjects and found plasma concentrations among epileptics to be comparable in general to those of controls, but that two or three classes of plasma taurine concentrations, possibly genetically regulated, occur in both epileptic and control subjects. Our previous studies and data from the present study on taurine excretion revealed three excretion classes under genetic control. The principal finding is that epileptics include disproportionate numbers of low excretors (high reabsorbers), who are presumptive homozygotes for the allele effecting higher reabsorption. If confirmed, these findings suggest that the transport of taurine, rather than absolute taurine concentration, may explain the efficacy of taurine administration in some epileptics but not in others. The locus involved may be one component in the polygenic diathesis to the idiopathic epilepsies.

Taurine transport in epilepsy

Previous studies of plasma taurine concentrations in epileptics have yielded equivocal results. We measured plasma and urinary taurine in 41 epileptic and 68 control subjects and found plasma concentrations among epileptics to be comparable in general to those of controls, but that two or three classes of plasma taurine concentrations, possibly genetically regulated, occur in both epileptic and control subjects. Our previous studies and data from the present study on taurine excretion revealed three excretion classes under genetic control. The principal finding is that epileptics include disproportionate numbers of low excretors (high reabsorbers), who are presumptive homozygotes for the allele effecting higher reabsorption. If confirmed, these findings suggest that the transport of taurine, rather than absolute taurine concentration, may explain the efficacy of taurine administration in some epileptics but not in others. The locus involved may be one component in the polygenic diathesis to the idiopathic epilepsies.

Potential sources of errors in cation-exchange chromatographic measurement of plasma taurine

We examined the potential sources of error in automated cation-exchange chromatographic quantitation of plasma taurine, both in sample preparation and in the analysis. Principal sources of error include: use of serum instead of plasma, which produces gross overestimates; use of tripotassium ethylenediaminetetraacetate (EDTA) as anticoagulant in systems involving ninhydrin detection (a ninhydrin-positive contaminant of EDTA emerges coincident with taurine); contamination with platelets; and placing volumes exceeding 20 microL on the cartridge used in the Technicon TSM Amino Acid Analyzer. We arrived at a simple technique in which we use EDTA as anticoagulant, micropore filtration to produce platelet-free plasma, and o-phthalaldehyde as the detection reagent for the sensitivity required to measure accurately the low concentration of taurine in plasma.

Potential sources of errors in cation-exchange chromatographic measurement of plasma taurine

We examined the potential sources of error in automated cation-exchange chromatographic quantitation of plasma taurine, both in sample preparation and in the analysis. Principal sources of error include: use of serum instead of plasma, which produces gross overestimates; use of tripotassium ethylenediaminetetraacetate (EDTA) as anticoagulant in systems involving ninhydrin detection (a ninhydrin-positive contaminant of EDTA emerges coincident with taurine); contamination with platelets; and placing volumes exceeding 20 microL on the cartridge used in the Technicon TSM Amino Acid Analyzer. We arrived at a simple technique in which we use EDTA as anticoagulant, micropore filtration to produce platelet-free plasma, and o-phthalaldehyde as the detection reagent for the sensitivity required to measure accurately the low concentration of taurine in plasma.

Potential sources of errors in cation-exchange chromatographic measurement of plasma taurine

We examined the potential sources of error in automated cation-exchange chromatographic quantitation of plasma taurine, both in sample preparation and in the analysis. Principal sources of error include: use of serum instead of plasma, which produces gross overestimates; use of tripotassium ethylenediaminetetraacetate (EDTA) as anticoagulant in systems involving ninhydrin detection (a ninhydrin-positive contaminant of EDTA emerges coincident with taurine); contamination with platelets; and placing volumes exceeding 20 microL on the cartridge used in the Technicon TSM Amino Acid Analyzer. We arrived at a simple technique in which we use EDTA as anticoagulant, micropore filtration to produce platelet-free plasma, and o-phthalaldehyde as the detection reagent for the sensitivity required to measure accurately the low concentration of taurine in plasma.

Taurine transport in epilepsy

Previous studies of plasma taurine concentrations in epileptics have yielded equivocal results. We measured plasma and urinary taurine in 41 epileptic and 68 control subjects and found plasma concentrations among epileptics to be comparable in general to those of controls, but that two or three classes of plasma taurine concentrations, possibly genetically regulated, occur in both epileptic and control subjects. Our previous studies and data from the present study on taurine excretion revealed three excretion classes under genetic control. The principal finding is that epileptics include disproportionate numbers of low excretors (high reabsorbers), who are presumptive homozygotes for the allele effecting higher reabsorption. If confirmed, these findings suggest that the transport of taurine, rather than absolute taurine concentration, may explain the efficacy of taurine administration in some epileptics but not in others. The locus involved may be one component in the polygenic diathesis to the idiopathic epilepsies.