Joint species distribution modeling reveals a changing prey landscape for North Pacific right whales on the Bering shelf.

The eastern North Pacific right whale (NPRW) is the most endangered population of whale and has been observed north of its core feeding ground in recent years with low sea ice extent. Sea ice and water temperature are important drivers for zooplankton dynamics within the whale's core feeding ground in the southeastern Bering Sea, seasonally forming stable fronts along the shelf that give rise to distinct zooplankton communities. A northward shift in NPRW distribution driven by changing distribution of prey resources could put this species at increased risk of entanglement and vessel strikes. We modeled the abundance of NPRW prey, Calanus glacialis, Neocalanus, and Thysanoessa species, using a dynamic biophysical food web model of nine zooplankton guilds in the Bering shelf zooplankton community during a period of warming (2006-2016). This model is unique among prior zooplankton studies from the region in that it includes density dependence, thereby allowing us to ask whether species interactions influence zooplankton dynamics. Modeling confirmed the importance of sea ice and ocean temperature to zooplankton dynamics in the region. Density-independent growth drove community dynamics, while dependent factors were comparatively minimal. Overall, Calanus responded to environment terms, with the strength and direction of response driven by copepodite stage. Neocalanus and Thysanoessa responses were weaker, likely due to their primary occurrence on the outer shelf. We also modeled the steady-state (equilibrium) abundance of Calanus in conditions with and without wind gusts to test whether advection of outer shelf species might disrupt the steady-state dynamics of Calanus abundance; the results did not support disruption. Given the annual fall sampling design, we interpret our results as follows: low-ice-extent winters induced stronger spring winds and weakened fronts on the shelf, thereby advecting some outer shelf species into the study region; increased development rates in these warm conditions influenced the proportion of C. glacialis copepodite stages over the season. Residual correlation suggests missing drivers, possibly predators, and phytoplankton bloom composition. Given the continued loss of sea ice in the region and projected continued warming, our findings suggest that C. glacialis will move northward, and thus, whales may move northward to continue targeting them.

Prevalence and significance of large granular lymphocytes in patients with immune thrombocytopenia.

The association between T-cell large granular lymphocytes (T-LGL) and ITP is uncertain. The aims of this study were to determine the prevalence of T-LGL in patients with ITP and to describe its association with ITP disease severity. We analyzed flow cytometry results for T-LGL (using a threshold of 0.3 x109 or greater cells/L) or positive T-cell receptor clonality in patients with ITP and nonimmune thrombocytopenia. Descriptive statistics were used to characterize the association between T-LGL and ITP, response to ITP treatments (rituximab and splenectomy) and response to T-LGL treatment. Among ITP patients, 14.3% (13/91) had evidence of a T-LGL population compared to 10.3% (3/29) of patients with non-immune thrombocytopenia. ITP patients with T-LGL had lower nadir platelet counts (2 vs. 47 × 109/L) and received more ITP treatments (median 6 vs. 3) than ITP patients without T-LGL. Response to rituximab was observed in 14.3% (1/7) of ITP patients with T-LGL and 54.5% (6/11) without T-LGL. Response to splenectomy was observed in 25% (2/8) with T-LGL and 56.2% (9/16) without T-LGL. Four patients with ITP and T-LGL received treatment for T-LGL with methotrexate; none had an improvement in platelet count levels. T-LGL may appear in patients with ITP, and the meaning of this finding remains unclear; however, for some patients, the presence of abnormal T-LGL may indicate a more severe form of ITP that tends to be less responsive to therapy. In this cohort, treatment of T-LGL with methotrexate did not improve platelet counts in the few patients who were treated.

Paralytic shellfish toxins in Alaskan Arctic food webs during the anomalously warm ocean conditions of 2019 and estimated toxin doses to Pacific walruses and bowhead whales.

Climate change-related ocean warming and reduction in Arctic sea ice extent, duration and thickness increase the risk of toxic blooms of the dinoflagellate Alexandrium catenella in the Alaskan Arctic. This algal species produces neurotoxins that impact marine wildlife health and cause the human illness known as paralytic shellfish poisoning (PSP). This study reports Paralytic Shellfish Toxin (PST) concentrations quantified in Arctic food web samples that include phytoplankton, zooplankton, benthic clams, benthic worms, and pelagic fish collected throughout summer 2019 during anomalously warm ocean conditions. PSTs (saxitoxin equivalents, STX eq.) were detected in all trophic levels with concentrations above the seafood safety regulatory limit (80 µg STX eq. 100 g-1) in benthic clams collected offshore on the continental shelf in the Beaufort, Chukchi, and Bering Seas. Most notably, toxic benthic clams (Macoma calcarea) were found north of Saint Lawrence Island where Pacific walruses (Odobenus rosmarus) are known to forage for a variety of benthic species, including Macoma. Additionally, fecal samples collected from 13 walruses harvested for subsistence purposes near Saint Lawrence Island during March to May 2019, all contained detectable levels of STX, with fecal samples from two animals (78 and 72 µg STX eq. 100 g-1) near the seafood safety regulatory limit. In contrast, 64% of fecal samples from zooplankton-feeding bowhead whales (n = 9) harvested between March and September 2019 in coastal waters of the Beaufort Sea near Utqiagvik (formerly Barrow) and Kaktovik were toxin-positive, and those levels were significantly lower than in walruses (max bowhead 8.5 µg STX eq. 100 g-1). This was consistent with the lower concentrations of PSTs found in regional zooplankton prey. Maximum ecologically-relevant daily toxin doses to walruses feeding on clams and bowhead whales feeding on zooplankton were estimated to be 21.5 and 0.7 µg STX eq. kg body weight-1 day-1, respectively, suggesting that walruses had higher PST exposures than bowhead whales. Average and maximum STX doses in walruses were in the range reported previously to cause illness and/or death in humans and humpback whales, while bowhead whale doses were well below those levels. These findings raise concerns regarding potential increases in PST/STX exposure risks and health impacts to Arctic marine mammals as ocean warming and sea ice reduction continue.

On-Demand Patient-Specific Phenotype-to-Genotype Ebola Virus Characterization.

Biosafety, biosecurity, logistical, political, and technical considerations can delay or prevent the wide dissemination of source material containing viable virus from the geographic origin of an outbreak to laboratories involved in developing medical countermeasures (MCMs). However, once virus genome sequence information is available from clinical samples, reverse-genetics systems can be used to generate virus stocks de novo to initiate MCM development. In this study, we developed a reverse-genetics system for natural isolates of Ebola virus (EBOV) variants Makona, Tumba, and Ituri, which have been challenging to obtain. These systems were generated starting solely with in silico genome sequence information and have been used successfully to produce recombinant stocks of each of the viruses for use in MCM testing. The antiviral activity of MCMs targeting viral entry varied depending on the recombinant virus isolate used. Collectively, selecting and synthetically engineering emerging EBOV variants and demonstrating their efficacy against available MCMs will be crucial for answering pressing public health and biosecurity concerns during Ebola disease (EBOD) outbreaks.

Ecosystem response persists after a prolonged marine heatwave.

Some of the longest and most comprehensive marine ecosystem monitoring programs were established in the Gulf of Alaska following the environmental disaster of the Exxon Valdez oil spill over 30 years ago. These monitoring programs have been successful in assessing recovery from oil spill impacts, and their continuation decades later has now provided an unparalleled assessment of ecosystem responses to another newly emerging global threat, marine heatwaves. The 2014-2016 northeast Pacific marine heatwave (PMH) in the Gulf of Alaska was the longest lasting heatwave globally over the past decade, with some cooling, but also continued warm conditions through 2019. Our analysis of 187 time series from primary production to commercial fisheries and nearshore intertidal to offshore oceanic domains demonstrate abrupt changes across trophic levels, with many responses persisting up to at least 5 years after the onset of the heatwave. Furthermore, our suite of metrics showed novel community-level groupings relative to at least a decade prior to the heatwave. Given anticipated increases in marine heatwaves under current climate projections, it remains uncertain when or if the Gulf of Alaska ecosystem will return to a pre-PMH state.

The effects of temperature on Bosmina longirostris susceptibility to microcystin-LR acute toxicity.

Harmful algal blooms are an ongoing threat to many aquatic systems throughout the world. In the Chowan River, North Carolina, the frequency of toxin producing Microcystis aeruginosa blooms has increased since 1975 along with an average 0.71°C rise in water temperature. The combined effect of microcystin-LR toxin and rising temperatures on a dominant zooplankter in the system, Bosmina longirostris, was the focus of this study. Laboratory studies were conducted to determine how microcystin-LR, produced from M. aeruginosa blooms, affected B. longirostris mortality under different temperature regimes. At 25°C, the LC50 for B. longirostris was 26.3 µg L-1 suggesting that B. longirostris can survive typical current bloom microcystin-LR concentrations ranging 0.1µg L-1 to 2.0 µg L-1, but would be susceptible to higher concentrations they may be periodically exposed to. Mortality was assessed at a constant microcystin-LR concentration of 26.3 µg L-1 over 15-35°C, and it was found that B. longirostris mortality increased at higher temperatures. B. longirostris mortality increased approximately 18% due to microcystin-LR alone over 2°C between 25°C and 27°C when exposed to the LC50 concentration. The increased prevalence of toxic M. aeruginosa blooms and increasing temperatures due to climate change may reduce B. longirostris populations, potentially affecting larval fish and fisheries in the Chowan River, North Carolina.

Changes in zooplankton community, and seston and zooplankton fatty acid profiles at the freshwater/saltwater interface of the Chowan River, North Carolina.

The variability in zooplankton fatty acid composition may be an indicator of larval fish habitat quality as fatty acids are linked to fish larval growth and survival. We sampled an anadromous fish nursery, the Chowan River, during spring of 2013 in order to determine how the seston fatty acid composition varied in comparison with the zooplankton community composition and fatty acid composition during the period of anadromous larval fish residency. The seston fatty acid profiles showed no distinct pattern in relation to sampling time or location. The mesozooplankton community composition varied spatially and the fatty acid profiles were typical of freshwater species in April. The Chowan River experienced a saltwater intrusion event during May, which resulted in brackish water species dominating the zooplankton community and the fatty acid profile showed an increase in polyunsaturated fatty acids (PUFA), in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The saltwater intrusion event was followed by an influx of freshwater due to high precipitation levels in June. The zooplankton community composition once again became dominated by freshwater species and the fatty acid profiles shifted to reflect this change; however, EPA levels remained high, particularly in the lower river. We found correlations between the seston, microzooplankton and mesozooplankton fatty acid compositions. Salinity was the main factor correlated to the observed pattern in species composition, and fatty acid changes in the mesozooplankton. These data suggest that anadromous fish nursery habitat likely experiences considerable spatial variability in fatty acid profiles of zooplankton prey and that are correlated to seston community composition and hydrodynamic changes. Our results also suggest that sufficient prey density as well as a diverse fatty acid composition is present in the Chowan River to support larval fish production.

Return of warm conditions in the southeastern Bering Sea: Phytoplankton - Fish.

In 2014, the Bering Sea shifted back to warmer ocean temperatures (+2 oC above average), bringing concern for the potential for a new warm stanza and broad biological and ecological cascading effects. In 2015 and 2016 dedicated surveys were executed to study the progression of ocean heating and ecosystem response. We describe ecosystem response to multiple, consecutive years of ocean warming and offer perspective on the broader impacts. Ecosystem changes observed include reduced spring phytoplankton biomass over the southeast Bering Sea shelf relative to the north, lower abundances of large-bodied crustacean zooplankton taxa, and degraded feeding and body condition of age-0 walleye pollock. This suggests poor ecosystem conditions for young pollock production and the risk of significant decline in the number of pollock available to the pollock fishery in 2-3 years. However, we also noted that high quality prey, large copepods and euphausiids, and lower temperatures in the north may have provided a refuge from poor conditions over the southern shelf, potentially buffering the impact of a sequential-year warm stanza on the Bering Sea pollock population. We offer the hypothesis that juvenile (age-0, age-1) pollock may buffer deleterious warm stanza effects by either utilizing high productivity waters associated with the strong, northerly Cold Pool, as a refuge from the warm, low production areas of the southern shelf, or by exploiting alternative prey over the southern shelf. We show that in 2015, the ocean waters influenced by spring sea ice (the Cold Pool) supported robust phytoplankton biomass (spring) comprised of centric diatom chains, a crustacean copepod community comprised of large-bodied taxa (spring, summer), and a large aggregation of midwater fishes, potentially young pollock. In this manner, the Cold Pool may have acted as a trophic refuge in that year. The few age-0 pollock occurring over the southeast shelf consumed high numbers of euphausiids which may have provided a high quality alternate prey. In 2016 a retracted Cold Pool precluded significant refuging in the north, though pollock foraging on available euphausiids over the southern shelf may have mitigated the effect of warm waters and reduced large availability of large copepods. This work presents the hypothesis that, in the short term, juvenile pollock can mitigate the drastic impacts of sustained warming. This short-term buffering, combined with recent observations (2017) of renewed sea ice presence over southeast Bering Sea shelf and a potential return to average or at least cooler ecosystem conditions, suggests that recent warm year stanza (2014-2016) effects to the pollock population and fishery may be mitigated.

A Multicomponent Animal Virus Isolated from Mosquitoes.

RNA viruses exhibit a variety of genome organization strategies, including multicomponent genomes in which each segment is packaged separately. Although multicomponent genomes are common among viruses infecting plants and fungi, their prevalence among those infecting animals remains unclear. We characterize a multicomponent RNA virus isolated from mosquitoes, designated Guaico Culex virus (GCXV). GCXV belongs to a diverse clade of segmented viruses (Jingmenvirus) related to the prototypically unsegmented Flaviviridae. The GCXV genome comprises five segments, each of which appears to be separately packaged. The smallest segment is not required for replication, and its presence is variable in natural infections. We also describe a variant of Jingmen tick virus, another Jingmenvirus, sequenced from a Ugandan red colobus monkey, thus expanding the host range of this segmented and likely multicomponent virus group. Collectively, this study provides evidence for the existence of multicomponent animal viruses and their potential relevance for animal and human health.

Gene expression profiling of 49 human tumor xenografts from in vitro culture through multiple in vivo passages--strategies for data mining in support of therapeutic studies.

BACKGROUND: Development of cancer therapeutics partially depends upon selection of appropriate animal models. Therefore, improvements to model selection are beneficial. RESULTS: Forty-nine human tumor xenografts at in vivo passages 1, 4 and 10 were subjected to cDNA microarray analysis yielding a dataset of 823 Affymetrix HG-U133 Plus 2.0 arrays. To illustrate mining strategies supporting therapeutic studies, transcript expression was determined: 1) relative to other models, 2) with successive in vivo passage, and 3) during the in vitro to in vivo transition. Ranking models according to relative transcript expression in vivo has the potential to improve initial model selection. For example, combining p53 tumor expression data with mutational status could guide selection of tumors for therapeutic studies of agents where p53 status purportedly affects efficacy (e.g., MK-1775). The utility of monitoring changes in gene expression with extended in vivo tumor passages was illustrated by focused studies of drug resistance mediators and receptor tyrosine kinases. Noteworthy observations included a significant decline in HCT-15 colon xenograft ABCB1 transporter expression and increased expression of the kinase KIT in A549 with serial passage. These trends predict sensitivity to agents such as paclitaxel (ABCB1 substrate) and imatinib (c-KIT inhibitor) would be altered with extended passage. Given that gene expression results indicated some models undergo profound changes with in vivo passage, a general metric of stability was generated so models could be ranked accordingly. Lastly, changes occurring during transition from in vitro to in vivo growth may have important consequences for therapeutic studies since targets identified in vitro could be over- or under-represented when tumor cells adapt to in vivo growth. A comprehensive list of mouse transcripts capable of cross-hybridizing with human probe sets on the HG-U133 Plus 2.0 array was generated. Removal of the murine artifacts followed by pairwise analysis of in vitro cells with respective passage 1 xenografts and GO analysis illustrates the complex interplay that each model has with the host microenvironment. CONCLUSIONS: This study provides strategies to aid selection of xenograft models for therapeutic studies. These data highlight the dynamic nature of xenograft models and emphasize the importance of maintaining passage consistency throughout experiments.

Real-time PCR-based assay to quantify the relative amount of human and mouse tissue present in tumor xenografts.

BACKGROUND: Xenograft samples used to test anti-cancer drug efficacies and toxicities in vivo contain an unknown mix of mouse and human cells. Evaluation of drug activity can be confounded by samples containing large amounts of contaminating mouse tissue. We have developed a real-time quantitative polymerase chain reaction (qPCR) assay using TaqMan technology to quantify the amount of mouse tissue that is incorporated into human xenograft samples. RESULTS: The forward and reverse primers bind to the same DNA sequence in the human and the mouse genome. Using a set of specially designed fluorescent probes provides species specificity. The linearity and sensitivity of the assay is evaluated using serial dilutions of single species and heterogeneous DNA mixtures. We examined many xenograft samples at various in vivo passages, finding a wide variety of human:mouse DNA ratios. This variation may be influenced by tumor type, number of serial passages in vivo, and even which part of the tumor was collected and used in the assay. CONCLUSIONS: This novel assay provides an accurate quantitative assessment of human and mouse content in xenograft tumors. This assay can be performed on aberrantly behaving human xenografts, samples used in bioinformatics studies, and periodically for tumor tissue frequently grown by serial passage in vivo.

Phase II study of subcutaneous octreotide in adults with recurrent or progressive meningioma and meningeal hemangiopericytoma.

The objective of this phase II study was to evaluate the efficacy and safety of subcutaneous octreotide therapy for the treatment of recurrent meningioma and meningeal hemangiopericytoma. Octreotide is an agonist of somatostatin receptors, which are frequently expressed in meningioma, and reports have suggested that treatment with somatostatin agonists may lead to objective response in meningioma. Patients with recurrent/progressive meningioma or meningeal hemangiopericytoma were eligible for enrollment; those with atypical/anaplastic meningioma or hemangiopericytoma must have experienced disease progression despite radiotherapy or have had a contraindication to radiation. Patients received subcutaneous octreotide with a goal dose of 500 µg 3 times per day, as tolerated. Imaging was performed every 3 months during therapy. The primary outcome measure was radiographic response rate. Eleven patients with meningioma and 1 with meningeal hemangiopericytoma were enrolled during the period 1992-1998. Side effects included diarrhea (grade 1 in 4 patients and grade 2 in 2), nausea or anorexia (grade 1 in 4 patients), and transaminitis (grade 1 in 1 patient). One patient developed extra hepatic cholangiocarcinoma, which was likely unrelated to octreotide therapy. No radiographic responses were observed. Eleven of the 12 patients experienced progression, with a median time to progression of 17 weeks. Two patients experienced long progression-free intervals (30 months and ≥18 years). Eleven patients have died. Median duration of survival was 2.7 years. Immunohistochemical staining of somatostatin receptor Sstr2a expression in a subset of patients did not reveal a correlation between level of expression and length of progression-free survival. Octreotide was well-tolerated but failed to produce objective tumor response, although 2 patients experienced prolonged stability of previously progressive tumors.

Enteral tube feeding and pneumonia.

To determine the effects of enteral tube feeding on the incidence of pneumonia, we performed a retrospective review of all clients at our institution who had gastrostomy or jejunostomy tubes placed over a 10-year period. Ninety-three subjects had a history of pneumonia before feeding tube insertion. Eighty had gastrostomy and 13, jejunostomy tubes. There was a 45% decrease in the incidence of pneumonia in the year following tube insertion compared to the prior year. This improvement was seen in gastrostomy and in jejunostomy tubes, but was only statistically significant in gastrostomy tubes. We conclude that although feeding tubes do not completely prevent pneumonia, there is an immediate decrease in the incidence of pneumonia following tube placement.

Immunomodulatory treatment trial for paraneoplastic neurological disorders.

Paraneoplastic neurological disorders are devastating remote effects of malignancy. Despite compelling evidence of an autoimmune pathogenesis, empiric immunomodulatory treatment of these disorders is often ineffective. However, very few systematic studies have been conducted, and the treatment of patients without active malignancy has not been addressed. We conducted a prospective open-label treatment study of plasma exchange plus conventional cancer chemotherapy (10 patients) or plasma exchange plus continuous oral cyclophosphamide (10 patients). All patients had progressive symptoms and at least moderate disability at enrollment (mean Rankin score, 3.4). Patients who had experienced symptoms for more than 12 months were excluded (mean duration of symptoms at enrollment, 3.6 months). The primary outcome measure was change in quantitative disability measures (Rankin and Barthel scores) after 6 months of treatment; a positive response was defined as stability or improvement in disability. Overall, 50% of patients had a positive response at 6 months (6 patients had improved by at least 1 Rankin grade). Patients with good outcome tended to be those with less disability at time of enrollment. Hematologic toxicity was common among those receiving cyclophosphamide. Aggressive immunosuppression early in the clinical course should be considered in patients who have paraneoplastic neurological disorders, even when there is no evidence of active malignancy.

Protein expression signatures: an application of proteomics.

The methods of proteomics, the study of the protein complement of the genome, are applicable to environmental testing. Sets of proteins specific to different stressors can be isolated using computer imaging software. Individual proteins can be identified by mass spectrometry. The Protein Expression Signatures (PES) obtained have potential in diagnosing adverse factors in the environment. The challenge is to demonstrate their feasibility in complex environments. We have shown that PES for three endocrine disrupting compounds in trout (Onchorhynchus mykiss), can be detected in mixed sewage effluent. Other studies support these results. As protein databases expand, identification becomes routine, and capture molecules specific to each protein are developed, the possibility of simple field tests for multiple stressors becomes real.

Risk of cancer among relatives of patients with glioma.

We report a population-based, retrospective study of 396 Icelandic people diagnosed with glioma in the years 1940-1995. The purpose of this study was to test whether astrocytomas, other glial tumors, other central nervous system tumors, or other cancers aggregate in families identified through glioma probands who were of Icelandic origin. Pedigrees of the 396 cases were traced by the Genetical Committee of the University of Iceland and linked to the Icelandic Cancer Registry. A total of 25,546 relatives, including 2,080 individuals with cancer were identified within these pedigrees. There was no statistically significant increase of glioma in relatives of glioma patients, nor was there any statistically significant increase in risk for other central nervous system tumors. There was no overall increase in incidence of all cancer combined, nor of specific common cancers (lung, prostate, breast, stomach, and colorectal) and uncommon cancers (melanoma and pancreas) in the relatives of glioma patients. Our results do not support the hypothesis of a familial aggregation of glioma indicative of a glioma susceptibility gene.