bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human Placental Syncytiotrophoblasts Restrict
Toxoplasma gondii
Attachment and Replication and Respond to Infection by Producing Immunomodulatory Chemokines
Authors: Ander Stephanie E. , Rudzki Elizabeth N. , Arora Nitin , Sadovsky Yoel , Coyne Carolyn B. , Boyle Jon P. 
Published: January 2018

ABSTRACT

Toxoplasma gondii
is a major source of congenital disease worldwide, but the cellular and molecular factors associated with its vertical transmission are largely unknown. In humans, the placenta forms the key interface between the maternal and fetal compartments and forms the primary barrier that restricts the hematogenous spread of microorganisms. Here, we utilized primary human trophoblast (PHT) cells isolated from full-term placentas and human midgestation chorionic villous explants to determine the mechanisms by which human trophoblasts restrict and respond to
T. gondii
infection. We show that placental syncytiotrophoblasts, multinucleated cells that are in direct contact with maternal blood, restrict
T. gondii
infection at two distinct stages of the parasite lytic cycle—at the time of attachment and also during intracellular replication. Utilizing comparative transcriptome sequencing (RNA-seq) transcriptional profiling, we also show that human placental trophoblasts from both the second and third trimesters respond uniquely to
T. gondii
infection compared to trophoblast cell lines, typified by the upregulation of several immunity-related genes. One of the most differentially induced genes was the chemokine CCL22, which relies on the secretion of a parasite effector(s) either during or after invasion for its induction. Collectively, our findings provide new insights into the mechanisms by which the human placenta restricts the vertical transmission of
T. gondii
at early and late stages of human pregnancy and demonstrate the existence of at least two interferon-independent pathways that restrict
T. gondii
access to the fetal compartment.

IMPORTANCE
Toxoplasma gondii
is a major source of congenital disease worldwide and must breach the placental barrier to be transmitted from maternal blood to the developing fetus. The events associated with the vertical transmission of
T. gondii
are largely unknown. Here, we show that primary human syncytiotrophoblasts, the fetus-derived cells that comprise the primary placental barrier, restrict
T. gondii
infection at two distinct stages of the parasite life cycle and respond to infection by inducing a unique immunomodulatory transcriptional profile. Collectively, our findings provide important insights into the mechanisms by which human syncytiotrophoblasts restrict
T. gondii
infection at early and late stages of human pregnancy, identify both permissive and resistant human placental cell types, and identify the placenta-enriched signaling pathways induced in response to infection.
Lamp1 Increases the Efficiency of Lassa Virus Infection by Promoting Fusion in Less Acidic Endosomal Compartments
Authors: Hulseberg Christine E. , Fénéant Lucie , Szymańska Katarzyna M. , White Judith M. 
Published: January 2018

ABSTRACT
Lassa virus (LASV) is an arenavirus whose entry into host cells is mediated by a glycoprotein complex (GPC) comprised of a receptor binding subunit, GP1, a fusogenic transmembrane subunit, GP2, and a stable signal peptide. After receptor-mediated internalization, arenaviruses converge in the endocytic pathway, where they are thought to undergo low-pH-triggered, GPC-mediated fusion with a late endosome membrane. A unique feature of LASV entry is a pH-dependent switch from a primary cell surface receptor (α-dystroglycan) to an endosomal receptor, lysosomal-associated membrane protein (Lamp1). Despite evidence that the interaction between LASV GP1 and Lamp1 is critical, the function of Lamp1 in promoting LASV infection remains poorly characterized. Here we used wild-type (WT) and Lamp1 knockout (KO) cells to show that Lamp1 increases the efficiency of, but is not absolutely required for, LASV entry and infection. We then used cell-cell and pseudovirus-cell surface fusion assays to demonstrate that LASV GPC-mediated fusion occurs at a significantly higher pH when Lamp1 is present compared to when Lamp1 is missing. Correspondingly, we found that LASV entry occurs through less acidic endosomes in WT (Lamp1-positive) versus Lamp1 KO cells. We propose that, by elevating the pH threshold for fusion, Lamp1 allows LASV particles to exit the endocytic pathway before they encounter an increasingly acidic and harsh proteolytic environment, which could inactivate a significant percentage of incoming viruses. In this manner Lamp1 increases the overall efficiency of LASV entry and infection.

IMPORTANCE
Lassa virus is the most clinically important member of the
Arenaviridae
, a family that includes six additional biosafety level 4 (BSL4) hemorrhagic fever viruses. The lack of specific antiviral therapies for Lassa fever drives an urgent need to identify druggable targets, and interventions that block infection at the entry stage are particularly attractive. Lassa virus is only the second virus known to employ an intracellular receptor, the first being Ebola virus. Here we show that interaction with its intracellular receptor, Lamp1, enhances and upwardly shifts the pH dependence of fusion and consistently permits Lassa virus entry into cells through less acidic endosomes. We propose that in this manner, Lamp1 increases the overall efficiency of Lassa virus infection.
The F-Box Protein Fbp1 Shapes the Immunogenic Potential of
Cryptococcus neoformans
Authors: Masso-Silva Jorge , Espinosa Vanessa , Liu Tong-Bao , Wang Yina , Xue Chaoyang , Rivera Amariliz 
Published: January 2018

ABSTRACT

Cryptococcus neoformans
is the main etiologic agent of cryptococcal meningitis and causes a significant number of deadly infections per year. Although it is well appreciated that host immune responses are crucial for defense against cryptococcosis, our understanding of factors that control the development of effective immunity to this fungus remains incomplete. In previous studies, we identified the F-box protein Fbp1 as a novel determinant of
C. neoformans
virulence. In this study, we found that the hypovirulence of the
fbp1
Δ mutant is linked to the development of a robust host immune response. Infection with the
fbp1
Δ mutant induces a rapid influx of CCR2
+
monocytes and their differentiation into monocyte-derived dendritic cells (mo-DCs). Depletion of CCR2
+
monocytes and their derivative mo-DCs resulted in impaired activation of a protective inflammatory response and the rapid death of mice infected with the
fbp1
Δ mutant. Mice lacking B and T cells also developed fungal meningitis and succumbed to infection with the
fbp1
Δ mutant, demonstrating that adaptive immune responses to the
fbp1
Δ mutant help to maintain the long-term survival of the host. Adaptive immune responses to the
fbp1
Δ mutant were characterized by enhanced differentiation of Th1 and Th17 CD4
+
T cells together with diminished Th2 responses compared to the H99 parental strain. Importantly, we found that the enhanced immunogenicity of
fbp1
Δ mutant yeast cells can be harnessed to confer protection against a subsequent infection with the virulent H99 parental strain. Altogether, our findings suggest that Fbp1 functions as a novel virulence factor that shapes the immunogenicity of
C. neoformans
.

IMPORTANCE
Cryptococcus neoformans
is the most common cause of deadly fungal meningitis, with over 270,000 infections per year. Immune responses are critically required for the prevention of cryptococcosis, and patients with impaired immunity and low CD4
+
T cell numbers are at high risk of developing these deadly infections. Although it is well appreciated that the development of protective immunity is shaped by the interactions of the host immune system with fungal cells, our understanding of fungal products that influence this process remains poor. In this study, we found that the activity of F-box protein 1 (Fbp1) in highly virulent
C. neoformans
clinical strain H99 shapes its immunogenicity and thus affects the development of protective immune responses in the host. The identification of this new mechanism of virulence may facilitate the future development of therapeutic interventions aimed at boosting antifungal host immunity.
O-Mannosylation of Proteins Enables
Histoplasma
Yeast Survival at Mammalian Body Temperatures
Authors: Garfoot Andrew L. , Goughenour Kristie D. , Wüthrich Marcel , Rajaram Murugesan V. S. , Schlesinger Larry S. , Klein Bruce S. , Rappleye Chad A. 
Published: January 2018

ABSTRACT

The ability to grow at mammalian body temperatures is critical for pathogen infection of humans. For the thermally dimorphic fungal pathogen
Histoplasma capsulatum
, elevated temperature is required for differentiation of mycelia or conidia into yeast cells, a step critical for invasion and replication within phagocytic immune cells. Posttranslational glycosylation of extracellular proteins characterizes factors produced by the pathogenic yeast cells but not those of avirulent mycelia, correlating glycosylation with infection.
Histoplasma
yeast cells lacking the Pmt1 and Pmt2 protein mannosyltransferases, which catalyze O-linked mannosylation of proteins, are severely attenuated during infection of mammalian hosts. Cells lacking Pmt2 have altered surface characteristics that increase recognition of yeast cells by the macrophage mannose receptor and reduce recognition by the β-glucan receptor Dectin-1. Despite these changes, yeast cells lacking these factors still associate with and survive within phagocytes. Depletion of macrophages or neutrophils
in vivo
does not recover the virulence of the mutant yeast cells. We show that yeast cells lacking Pmt functions are more sensitive to thermal stress
in vitro
and consequently are unable to productively infect mice, even in the absence of fever. Treatment of mice with cyclophosphamide reduces the normal core body temperature of mice, and this decrease is sufficient to restore the infectivity of O-mannosylation-deficient yeast cells. These findings demonstrate that O-mannosylation of proteins increases the thermotolerance of
Histoplasma
yeast cells, which facilitates infection of mammalian hosts.

IMPORTANCE
For dimorphic fungal pathogens, mammalian body temperature can have contrasting roles. Mammalian body temperature induces differentiation of the fungal pathogen
Histoplasma capsulatum
into a pathogenic state characterized by infection of host phagocytes. On the other hand, elevated temperatures represent a significant barrier to infection by many microbes. By functionally characterizing cells lacking O-linked mannosylation enzymes, we show that protein mannosylation confers thermotolerance on
H. capsulatum
, enabling infection of mammalian hosts.
Opioid errors in inpatient palliative care services: a retrospective review
Authors: Heneka Nicole , Shaw Tim , Rowett Debra , Lapkin Samuel , Phillips Jane L 
Published: January 2018

Opioids are a high-risk medicine frequently used to manage palliative patients’ cancer-related pain and other symptoms. Despite the high volume of opioid use in inpatient palliative care services, and the potential for patient harm, few studies have focused on opioid errors in this population.ObjectivesTo (i) identify the number of opioid errors reported by inpatient palliative care services, (ii) identify reported opioid error characteristics and (iii) determine the impact of opioid errors on palliative patient outcomes.MethodsA 24-month retrospective review of opioid errors reported in three inpatient palliative care services in one Australian state.ResultsOf the 55 opioid errors identified, 84% reached the patient. Most errors involved morphine (35%) or hydromorphone (29%). Opioid administration errors accounted for 76% of reported opioid errors, largely due to omitted dose (33%) or wrong dose (24%) errors. Patients were more likely to receive a lower dose of opioid than ordered as a direct result of an opioid error (57%), with errors adversely impacting pain and/or symptom management in 42% of patients. Half (53%) of the affected patients required additional treatment and/or care as a direct consequence of the opioid error.ConclusionThis retrospective review has provided valuable insights into the patterns and impact of opioid errors in inpatient palliative care services. Iatrogenic harm related to opioid underdosing errors contributed to palliative patients’ unrelieved pain. Better understanding the factors that contribute to opioid errors and the role of safety culture in the palliative care service context warrants further investigation.
Frequent use of emergency departments for mental and substance use disorders
Authors: Urbanoski Karen , Cheng Joyce , Rehm Jürgen , Kurdyak Paul 
Published: January 2018

ObjectivesWe described the population of people who frequently use ED for mental disorders, delineating differences by the number of visits for substance use disorders (SUDs), and predicted the receipt of follow-up services and 2-year mortality by the level of ED use for SUD.MethodsThis retrospective observational study included all Ontario residents 15 years and older who had five or more ED visits during any 12-month period from 2010 to 2012 (n=263 346). The study involved a secondary analysis of administrative health databases capturing emergency, hospital and ambulatory care. Frequent ED users for mental disorders (n=5416) were grouped into nested categories based on the number of ED visits for SUD. Logistic regression was used to examine group differences in the receipt of follow-up services and mortality, controlling for sociodemographics, comorbidities and past service use.ResultsThe majority of frequent ED users for mental disorders had at least one ED visit for SUD, most commonly involving alcohol. Relative to people with no visits for SUD, those with ED visits for SUD were older and more likely to be men (Ps <0.001). As the number of ED visits for SUD increased, the likelihood of receiving follow-up care, particularly specialist mental healthcare, declined while 2-year mortality steadily increased (Ps <0.001). These associations remained after controlling for comorbidities and past service use.ConclusionsFindings highlight disparities in the receipt of specialist care based on use of ED services for SUD, coupled with a greater mortality risk. There is a need for policies and procedures to help address unmet needs for care and to connect members of this vulnerable subgroup with services that are better able to support recovery and improve survival.
Temporal neural mechanisms underlying conscious access to different levels of facial stimulus contents
Authors: Hsu Shen-Mou , Yang Yu-Fang 
Published: January 2018

An important issue facing the empirical study of consciousness concerns how the contents of incoming stimuli gain access to conscious processing. According to classic theories, facial stimuli are processed in a hierarchical manner. However, it remains unclear how the brain determines which level of stimulus content is consciously accessible when facing an incoming facial stimulus. Accordingly, with a magnetoencephalography technique, this study aims to investigate the temporal dynamics of the neural mechanism mediating which level of stimulus content is consciously accessible. Participants were instructed to view masked target faces at threshold so that, according to behavioral responses, their perceptual awareness alternated from consciously accessing facial identity in some trials to being able to consciously access facial configuration features but not facial identity in other trials. Conscious access at these two levels of facial contents were associated with a series of differential neural events. Before target presentation, different patterns of phase angle adjustment were observed between the two types of conscious access. This effect was followed by stronger phase clustering for awareness of facial identity immediately during stimulus presentation. After target onset, conscious access to facial identity, as opposed to facial configural features, was able to elicit more robust late positivity. In conclusion, we suggest that the stages of neural events, ranging from prestimulus to stimulus-related activities, may operate in combination to determine which level of stimulus contents is consciously accessed. Conscious access may thus be better construed as comprising various forms that depend on the level of stimulus contents accessed. NEW & NOTEWORTHY The present study investigates how the brain determines which level of stimulus contents is consciously accessible when facing an incoming facial stimulus. Using magnetoencephalography, we show that prestimulus activities together with stimulus-related activities may operate in combination to determine conscious face detection or identification. This finding is distinct from the previous notion that conscious face detection precedes identification and provides novel insights into the temporal dynamics of different levels of conscious face perception.
Therapeutic Challenge with a CDK 4/6 Inhibitor Induces an RB-Dependent SMAC-Mediated Apoptotic Response in Non–Small Cell Lung Cancer
Authors: Thangavel Chellappagounder , Boopathi Ettickan , Liu Yi , McNair Christopher , Haber Alex , Perepelyuk Maryna , Bhardwaj Anshul , Addya Sankar , Ertel Adam , Shoyele Sunday , Birbe Ruth , Salvino Joseph M. , Dicker Adam P. , Knudsen Karen E. , Den Robert B. 
Published: January 2018

Abstract
Purpose: The retinoblastoma tumor suppressor (RB), a key regulator of cell-cycle progression and proliferation, is functionally suppressed in up to 50% of non–small cell lung cancer (NSCLC). RB function is exquisitely controlled by a series of proteins, including the CyclinD–CDK4/6 complex. In this study, we interrogated the capacity of a CDK4/6 inhibitor, palbociclib, to activate RB function.
Experimental Design and Results: We employed multiple isogenic RB-proficient and -deficient NSCLC lines to interrogate the cytostatic and cytotoxic capacity of CDK 4/6 inhibition in vitro and in vivo. We demonstrate that while short-term exposure to palbociclib induces cellular senescence, prolonged exposure results in inhibition of tumor growth. Mechanistically, CDK 4/6 inhibition induces a proapoptotic transcriptional program through suppression of IAPs FOXM1 and Survivin, while simultaneously augmenting expression of SMAC and caspase-3 in an RB-dependent manner.
Conclusions: This study uncovers a novel function of RB activation to induce cellular apoptosis through therapeutic administration of a palbociclib and provides a rationale for the clinical evaluation of CDK 4/6 inhibitors in the treatment of patients with NSCLC. Clin Cancer Res; 24(6); 1402–14. ©2018 AACR.
Hypergastrinemia in Long-Term Use of Proton Pump Inhibitors
Authors: Shiotani Akiko , Katsumata Ryo , Gouda Kyousuke  , Fukushima Shinya , Nakato Rui , Murao Takahisa , Ishii Manabu , Fujita Minoru , Matsumoto Hiroshi , Sakakibara Takashi 
Published: January 2018

Background/Aim: The use of proton pump inhibitors (PPIs) is known to lead to hypergastrinemia; however, the data in patients with atrophic gastritis is still lacking. The aim of this study was to investigate the effects of long-term PPIs use on the gastrin levels in patients with atrophic gastritis and to determine factors affecting hypergastrinemia in long-term users of PPIs. Methods: Serum Helicobacter pylori IgG, gastrin and pepsinogen levels were measured. Atrophic gastritis was assessed by upper gastrointestinal endoscopies based on the Kimura-Takemoto classification and pepsinogen levels. CYP2C19 polymorphisms were assessed using DNA extracted from peripheral blood. Results: A total number of 382 patients (275 men and 107 women) were enrolled. Median serum gastrin levels were higher in PPI users than in non- users (234 vs. 113 pg/mL, p < 0.001) and in women than in men (252 vs. 155 pg/mL, p = 0.006). Gastrin levels were significantly associated with corpus atrophy only in the subgroup of non-users of PPIs. Multivariate analysis revealed that hypergastrinemia (over 150 pg/mL) was significantly associated with PPI use (OR 5.30; 95% CI 3.32–8.47), women (OR 2.22; 95% CI 1.33–3.72) and corpus atrophy (OR 1.82; 95% CI 1.14–2.90). Conclusion: PPI use, women and corpus atrophy were risk factors for hypergastrinemia. Gender, but not corpus atrophy, affected the gastrin levels in long-term users of PPIs.
Long‐Term Exposure of Fine Particulate Matter Causes Hypertension by Impaired Renal D
1
Receptor–Mediated Sodium Excretion via Upregulation of G‐Protein–Coupled Receptor Kinase Type 4 Expression in Sprague‐Dawley Rats
Authors: Lu Xi , Ye Zhengmeng , Zheng Shuo , Ren Hongmei , Zeng Jing , Wang Xinquan , Jose Pedro A. , Chen Ken , Zeng Chunyu 
Published: January 2018

Background
Epidemiological evidence supports an important association between air pollution exposure and hypertension. However, the mechanisms are not clear.

Methods and Results

Our present study found that long‐term exposure to fine particulate matter (PM
2.5
) causes hypertension and impairs renal sodium excretion, which might be ascribed to lower D
1
receptor expression and higher D
1
receptor phosphorylation, accompanied with a higher G‐protein–coupled receptor kinase type 4 (GRK4) expression. The in vivo results were confirmed in in vitro studies (ie,
PM
2.5
increased basal and decreased D
1
receptor mediated inhibitory effect on Na
+
‐K
+
ATP
ase activity, decreased D
1
receptor expression, and increased D
1
receptor phosphorylation in renal proximal tubule cells). The downregulation of D
1
receptor expression and function might be attributable to a higher
GRK
4 expression after the exposure of renal proximal tubule cells to
PM
2.5
, because downregulation of
GRK
4 by small‐interfering
RNA
reversed the D
1
receptor expression and function. Because of the role of reactive oxygen species on D
1
receptor dysfunction and its relationship with air pollution exposure, we determined plasma reactive oxygen species and found the levels higher in
PM
2.5
‐treated Sprague‐Dawley rats. Inhibition of reactive oxygen species by tempol (4‐hydroxy‐2,2,6,6‐tetramethylpiperidin‐1‐oxyl) reduced blood pressure and increased sodium excretion in
PM
2.5
‐treated Sprague‐Dawley rats, accompanied by an increase in the low D
1
receptor expression, and decreased the hyperphosphorylated D
1
receptor and
GRK
4 expression.

Conclusions

Our present study indicated that long‐term exposure of
PM
2.5
increases blood pressure by decreasing D
1
receptor expression and function; reactive oxygen species, via regulation of
GRK
4 expression, plays an important role in the pathogenesis of
PM
2.5
‐induced hypertension.
Relationship Between Dietary Vitamin D and Deaths From Stroke and Coronary Heart Disease
Authors: Sheerah Haytham A. , Eshak Ehab S. , Cui Renzhe , Imano Hironori , Iso Hiroyasu , Tamakoshi Akiko 
Published: January 2018

Background and Purpose—
There is growing evidence about the importance of vitamin D for cardiovascular health. Therefore, we examined the relationship between dietary vitamin D intake and risk of mortality from stroke and coronary heart disease in Japanese population.

Methods—
A prospective study encompassing 58 646 healthy Japanese adults (23 099 men and 35  547 women) aged of 40 to 79 years in whom dietary vitamin D intake was determined via a self-administered food frequency questionnaire. The median follow-up period was 19.3 years (1989–2009). The hazard ratios and 95% confidence intervals of mortality were calculated using categories of vitamin D intake.

Results—

During 965 970 person-years of follow-up, 1514 stroke and 702 coronary heart disease deaths were documented. Vitamin D intake was inversely associated with risk of mortality from total stroke especially intraparenchymal hemorrhage but not from coronary heart disease; the multivariable hazard ratios (95% confidence intervals) for the highest (≥440 IU/d) versus lowest (<110 IU/D) categories of vitamin D intake were 0.70 (0.54–0.91;
P
for trend=0.04) for total stroke and 0.66 (0.46–0.96;
P
for trend=0.04) for intraparenchymal hemorrhage.

Conclusions—
Dietary vitamin D intake seems to be inversely associated with mortality from stroke.