bluuebunny/crossref_metadata_2025 huggingface dataset:
Like, it's important: The frequency and use of the discourse marker like in older autistic children
Authors: Jones Rebekah , Zane Emily R , Grossman Ruth B
Published: September 2022

Background & Aims

Discourse markers, such as well or like, serve a variety of functions to support conversational reciprocity: filling pauses, aiding word-finding, and modulating turn-taking by holding the conversational floor. Previous research shows that autistic individuals use discourse markers less frequently than non-autistic (NonAu) peers; however, the discourse marker like has not been included in that research, despite its ubiquitous use by NonAu individuals, and despite the fact that like serves important pragmatic functions that are not encoded by any other discourse marker. Specifically, like signals to the listener that the content of upcoming speech is 1) Important/new; 2) Loose/approximate; 3) Reformulative; or 4) Quotative. The current study addresses this gap in the literature by comparing the frequency of discourse marker like use between older autistic and non-autistic children as well as exploring patterns of usage between the four like functions.

Methods

Twenty-one 10-to-17-year-old children on the autism spectrum and 20 NonAu peers—statistically matched on age, sex, IQ and language scores—engaged in a semi-structured interview with a researcher. Uses of discourse-marker like were identified from written transcripts of interviews and each use was categorized into one of the four functions.

Results

There were no significant differences in like frequencies between groups, nor were there differences in relative proportions of functions used by each group.

Conclusions

Research consistently indicates that autistic individuals use discourse markers significantly less often than their NonAu counterparts, but the findings from our study suggest that this pattern does not persist to all such markers. This group of older autistic children use like as often as their peers and use it to signify similar information about upcoming speech to their listener.
The prevalence of thrombocytopenia in patients with acute cancer-associated thrombosis
Authors: Hsu Charles , Patell Rushad , Zwicker Jeffrey I.
Published: September 2022

Venous thromboembolism (VTE) and thrombocytopenia are frequently encountered complications in patients with cancer. Although there are several studies evaluating the safety and efficacy of anticoagulation regimens in patients with cancer-associated thrombosis (CAT) with thrombocytopenia, there is a paucity of data assessing the scope of the concurrent diagnoses. This study evaluates the prevalence of thrombocytopenia among patients with acute CAT. A retrospective cohort analysis of adult patients with cancer was conducted at Beth Israel Deaconess Medical Center between 2010 and 2021 with CAT (acute VTE within 6 months after new diagnosis of malignancy). VTE included acute deep vein thrombosis, pulmonary embolism, abdominal or intrathoracic venous thrombosis, and cerebral sinus thrombosis. The lowest platelet count within 2 weeks of (before or after) the index VTE event was identified to assess the frequency and grade of concurrent thrombocytopenia. We identified 3635 patients with CAT (80% solid tumors, 18% hematologic malignancies, and 2% multiple concurrent cancer diagnoses). Thrombocytopenia (defined as platelet count <100 000/μL) occurred in 22% (95% CI 21%-24%) of patients with CAT with solid tumors diagnoses and 47% (95% CI 43%-51%) of patients with CAT and hematologic malignancies. Severe thrombocytopenia (platelet count <50 000/μL) occurred in 7% (95% CI 6%-8%) of patients with solid tumors and 30% (95% CI 27%-34%) of patients with hematologic malignancies. Concurrent diagnoses of CAT and thrombocytopenia are very common, especially among patients with hematologic malignancies.
Identifying health related occupations of Twitter users through word embedding and deep neural networks
Authors: Zainab Kazi , Srivastava Gautam , Mago Vijay
Published: September 2022

Background

Twitter is a popular social networking site where short messages or “tweets” of users have been used extensively for research purposes. However, not much research has been done in mining the medical professions, such as detecting the occupations of users from their biographical contents. Mining such professions can be used to build efficient recommender systems for cost-effective targeted advertisements. Moreover, it is highly important to develop effective methods to identify the occupation of users since conventional classification methods rely on features developed by human intelligence. Although, the result may be favorable for the classification problem. However, it is still extremely challenging for traditional classifiers to predict the medical occupations accurately since it involves predicting multiple occupations. Hence this study emphasizes predicting the medical occupational class of users through their public biographical (“Bio”) content. We have conducted our analysis by annotating the bio content of Twitter users. In this paper, we propose a method of combining word embedding with state-of-art neural network models that include: Long Short Term Memory (LSTM), Bidirectional LSTM, Gated Recurrent Unit, Bidirectional Encoder Representations from Transformers, and A lite BERT. Moreover, we have also observed that by composing the word embedding with the neural network models there is no need to construct any particular attribute or feature. By using word embedding, the bio contents are formatted as dense vectors which are fed as input into the neural network models as a sequence of vectors.

Result

Performance metrics that include accuracy, precision, recall, and F1-score have shown a significant difference between our method of combining word embedding with neural network models than with the traditional methods. The scores have proved that our proposed approach has outperformed the traditional machine learning techniques for detecting medical occupations among users. ALBERT has performed the best among the deep learning networks with an F1 score of 0.90.

Conclusion

In this study, we have presented a novel method of detecting the occupations of Twitter users engaged in the medical domain by merging word embedding with state-of-art neural networks. The outcomes of our approach have demonstrated that our method can further advance the process of analyzing corpora of social media without going through the trouble of developing computationally expensive features.
Dense phenotyping from electronic health records enables machine learning-based prediction of preterm birth
Authors: Abraham Abin , Le Brian , Kosti Idit , Straub Peter , Velez-Edwards Digna R. , Davis Lea K. , Newton J. M. , Muglia Louis J. , Rokas Antonis , Bejan Cosmin A. , Sirota Marina , Capra John A.
Published: September 2022

Background

Identifying pregnancies at risk for preterm birth, one of the leading causes of worldwide infant mortality, has the potential to improve prenatal care. However, we lack broadly applicable methods to accurately predict preterm birth risk. The dense longitudinal information present in electronic health records (EHRs) is enabling scalable and cost-efficient risk modeling of many diseases, but EHR resources have been largely untapped in the study of pregnancy.

Methods

Here, we apply machine learning to diverse data from EHRs with 35,282 deliveries to predict singleton preterm birth.

Results

We find that machine learning models based on billing codes alone can predict preterm birth risk at various gestational ages (e.g., ROC-AUC = 0.75, PR-AUC = 0.40 at 28 weeks of gestation) and outperform comparable models trained using known risk factors (e.g., ROC-AUC = 0.65, PR-AUC = 0.25 at 28 weeks). Examining the patterns learned by the model reveals it stratifies deliveries into interpretable groups, including high-risk preterm birth subtypes enriched for distinct comorbidities. Our machine learning approach also predicts preterm birth subtypes (spontaneous vs. indicated), mode of delivery, and recurrent preterm birth. Finally, we demonstrate the portability of our approach by showing that the prediction models maintain their accuracy on a large, independent cohort (5978 deliveries) from a different healthcare system.

Conclusions

By leveraging rich phenotypic and genetic features derived from EHRs, we suggest that machine learning algorithms have great potential to improve medical care during pregnancy. However, further work is needed before these models can be applied in clinical settings.
Assessing the psychometric performance of EQ-5D-5L in dementia: a systematic review
Authors: Keetharuth Anju D. , Hussain Hannah , Rowen Donna , Wailoo Allan
Published: September 2022

Background

EQ-5D is widely used for valuing changes in quality of life for economic evaluation of interventions for people with dementia. There are concerns about EQ-5D-3L in terms of content validity, poor inter-rater agreement and reliability in the presence of cognitive impairment, but there is also evidence to support its use with this population. An evidence gap remains regarding the psychometric properties of EQ-5D-5L.

Objectives

To report psychometric evidence around EQ-5D-5L in people with dementia.

Methods

A systematic review identified primary studies reporting psychometric properties of EQ-5D-5L in people with dementia. Searches were completed up to November 2020. Study selection, data extraction and quality assessment were undertaken independently by at least 2 researchers.

Results

Evidence was extracted from 20 articles from 14 unique studies covering a range of dementia severity. Evidence of known group validity from 5 of 7 studies indicated that EQ-5D-5L distinguishes severity of disease measured by cognitive impairment, depression, level of dependence and pain. Convergent validity (9 studies) showed statistically significant correlations of weak and moderate strengths, between EQ-5D-5L scores and scores on other key measures. Statistically significant change was observed in only one of 6 papers that allowed this property to be examined. All seven studies showed a lack of inter-rater reliability between self and proxy reports with the former reporting higher EQ-5D-5L scores than those provided by proxies. Five of ten studies found EQ-5D-5L to be acceptable, assessed by whether the measure could be completed by the PwD and/or by the amount of missing data. As dementia severity increased, the feasibility of self-completing EQ-5D-5L decreased. Three papers reported on ceiling effects, two found some evidence in support of ceiling effects, and one did not.

Conclusions

EQ-5D-5L seems to capture the health of people with dementia on the basis of known-group validity and convergent validity, but evidence is inconclusive regarding the responsiveness of EQ-5D-5L. As disease progresses, the ability to self-complete EQ-5D-5L is diminished.
Effective hemodynamic monitoring
Authors: Pinsky Michael R. , Cecconi Maurizio , Chew Michelle S. , De Backer Daniel , Douglas Ivor , Edwards Mark , Hamzaoui Olfa , Hernandez Glenn , Martin Greg , Monnet Xavier , Saugel Bernd , Scheeren Thomas W. L. , Teboul Jean-Louis , Vincent Jean-Louis
Published: September 2022

Hemodynamic monitoring is the centerpiece of patient monitoring in acute care settings. Its effectiveness in terms of improved patient outcomes is difficult to quantify. This review focused on effectiveness of monitoring-linked resuscitation strategies from: (1) process-specific monitoring that allows for non-specific prevention of new onset cardiovascular insufficiency (CVI) in perioperative care. Such goal-directed therapy is associated with decreased perioperative complications and length of stay in high-risk surgery patients. (2) Patient-specific personalized resuscitation approaches for CVI. These approaches including dynamic measures to define volume responsiveness and vasomotor tone, limiting less fluid administration and vasopressor duration, reduced length of care. (3) Hemodynamic monitoring to predict future CVI using machine learning approaches. These approaches presently focus on predicting hypotension. Future clinical trials assessing hemodynamic monitoring need to focus on process-specific monitoring based on modifying therapeutic interventions known to improve patient-centered outcomes.
Early administration of hydrocortisone, vitamin C, and thiamine in adult patients with septic shock: a randomized controlled clinical trial
Authors: Lyu Qing-Quan , Zheng Rui-Qiang , Chen Qi-Hong , Yu Jiang-Quan , Shao Jun , Gu Xiao-Hua
Published: September 2022

Background

The combination therapy of hydrocortisone, vitamin C, and thiamine has been proposed as a potential treatment in patients with sepsis and septic shock. However, subsequent trials have reported conflicting results in relation to survival outcomes. Hence, we performed this randomized controlled trial (RCT) to evaluate the efficacy and safety of early combination therapy among adult patients with septic shock.

Methods

This single-center, double-blind RCT enrolled adult patients with diagnosis of septic shock within 12 h from Northern Jiangsu People's Hospital between February 2019 and June 2021. Recruited patients were randomized 1:1 to receive intervention (hydrocortisone 200 mg daily, vitamin C 2 g every 6 h, and thiamine 200 mg every 12 h) or placebo (0.9% saline) for 5 days or until ICU discharge. The primary endpoint was 90-day mortality. The secondary endpoints included mortality at day 28, ICU discharge, and hospital discharge; shock reversal; 72-h Delta SOFA score; ICU-free days, vasopressor-free days, and ventilator support -free days up to day 28; ICU length of stay (LOS) and hospital LOS.

Results

Among 426 patients randomized, a total of 408 patients with septic shock were included in the per-protocol (PP) analysis, of which 203 were assigned to the intervention group and 205 to the placebo group. In the PP population, the primary outcome of 90-day mortality was 39.9% (81/203) and 39.0% (80/205) in the intervention and the placebo groups, respectively, and was not significantly different (P = 0.86). There was no significant difference between two groups in 28-day mortality (36.5% vs. 36.1%, P = 0.94) or the ICU mortality (31.5% vs. 28.8%, P = 0.55) and hospital mortality (34.5% vs. 33.2%, P = 0.78). No other secondary outcomes showed significant differences between two groups, including shock reversal, vasopressor-free days, and ICU LOS. Intention-to-treat analysis included all the 426 patients and confirmed these results (all P > 0.05).

Conclusion

Among adult patients with septic shock, early use of hydrocortisone, vitamin C, and thiamine combination therapy compared with placebo did not confer survival benefits.

Trial registration ClinicalTrials.gov: NCT03872011, registration date: March 12, 2019.

Graphic Abstract
An algorithm for the anchor points of the PPS of the BCC model
Authors: Akbarian Dariush , Bani Ali Akbar , Rostamy-Malkhalifeh Mohsen , Hosseinzadeh Lotfi Farhad
Published: September 2022

Anchor points play an important role in data envelopment analysis theory and applications; they delineate the efficient part of the production possibility set (PPS) frontier.
In this paper, we propose an approach for finding the anchor points of the PPS of the Banker, Charnes and Cooper (BCC) model. This approach is based on a variant of super-efficiency models and their duals. The necessary and sufficient conditions for the characterization of the anchor points are also provided.
Finally, the applicability of the proposed model is illustrated with some numerical examples.
Superiority of quadratic over conventional neural networks for classification of gaussian mixture data
Authors: Qi Tianrui , Wang Ge
Published: September 2022

To enrich the diversity of artificial neurons, a type of quadratic neurons was proposed previously, where the inner product of inputs and weights is replaced by a quadratic operation. In this paper, we demonstrate the superiority of such quadratic neurons over conventional counterparts. For this purpose, we train such quadratic neural networks using an adapted backpropagation algorithm and perform a systematic comparison between quadratic and conventional neural networks for classificaiton of Gaussian mixture data, which is one of the most important machine learning tasks. Our results show that quadratic neural networks enjoy remarkably better efficacy and efficiency than conventional neural networks in this context, and potentially extendable to other relevant applications.
Effects of theophylline on human eosinophil functions: comparative study with neutrophil functions
Authors: Yasui Kozo , Agematsu Kazunaga , Shinozaki Koji , Hokibara Sho , Nagumo Haruo , Yamada Shinji , Kobayashi Norimoto , Komiyama Atsushi
Published: September 2022

The understanding of theophylline as a bronchodilator has been reconsidered in recent years. We undertook to determine its immunomodulatory actions in granulocytes and elucidate their mechanism. Preincubation of neutrophils with theophylline (10-5 to 5 × 10-3 M) had a biphasic effect on O2− production stimulated with N-formyl-methionyl-leucyl-phenylalanine or C5a. Theophylline potentiates O2− production via adenosine A2A receptor antagonism induced by receptor-linked agonists from neutrophils, but not from eosinophils. The addition of theophylline caused a significant decline in neutrophil chemotaxis at lower concentrations than those for eosinophil motility. Theophylline reduces neutrophil chemotaxis via adenosine A1 receptor antagonism. At high concentrations, with an intracellular cAMP accumulation as a result of phosphodiesterase (PDE) inhibition, theophylline also exerts an inhibitory effect on the O2− production and chemotaxis of both types of cells. The difference in theophylline’s effect on neutrophils and eosinophils appears to depend on the existence of specific adenosine receptors. Theophylline thus modulates granulocyte functions in association with specific adenosine receptor antagonism and cAMP-PDE inhibition.
Resting and activated T cells induce expression of E-selectin and VCAM-1 by vascular endothelial cells through a contact-dependent but CD40 ligand-independent mechanism
Authors: Yarwood Helen , Mason Justin C , Mahiouz Danuta , Sugars Katharine , Haskard Dorian O
Published: September 2022

This study explored the effect on endothelial cell (EC) activation of contact with T lymphocytes, which occurs during lymphocyte emigration into inflamed tissues. Addition of T cells to umbilical vein or dermal microvascular EC monolayers stimulated expression of EC E-selectin and VCAM-1. This response required direct cell:cell contact, but not T-cell activation. The capacity of resting CD4+ T cells to activate EC was restricted to the CD45RO+ subset and could be enhanced by 6 h prestimulation of T cells with PMA and ionomycin. The EC-stimulating capacity of resting or activated T cells was independent of CD40 ligand. Furthermore, inhibition of TNF-α/β and IL-1α/β, together with CD40 ligand, failed to inhibit EC activation by resting T cells and only inhibited the response to PMA- and ionomycin-activated T cells by 40 ± 18%. Our data suggest that T-cell-EC interactions can lead to EC activation through a novel contact-dependent, but CD40 ligand-independent, mechanism.
Parallel induction of epithelial surface-associated chemokine and proteoglycan by cellular hypoxia: implications for neutrophil activation
Authors: Furuta Glenn T , Dzus Andrea L , Taylor Cormac T , Colgan Sean P
Published: September 2022

Neutrophil-induced damage to the protective epithelium has been implicated in mucosal disorders associated with hypoxia, and such damage may be initiated by epithelial-derived chemokines. Because chemokines can bind to membrane proteoglycans, we hypothesized that chemokines may associate with epithelial surfaces and activate polymorphonuclear neutrophils (PMN). Epithelial hypoxia (pO2 20 torr) resulted in a time-dependent induction of interleukin-8 (IL-8) mRNA, soluble protein, as well as surface protein. Such surface IL-8 expression was demonstrated to be dependent on heparinase III expression, and extensions of these experiments indicated that hypoxia induces epithelial perlecan expression in parallel with IL-8. Finally, co-incubation of post-hypoxic epithelia with human PMN induced IL-8-dependent expression of the PMN β2-integrin CD11b/18. These data indicate that chemokines liberated from epithelia may exist in a surface-bound, bioactive form and that hypoxia may regulate proteoglycan expression.
Chronic PMA treatment of Jurkat T lymphocytes results in decreased protein tyrosine phosphorylation and inhibition of CD3- but not Ti-dependent antibody-triggered Ca2+ signaling
Authors: Ahnadi Charaf E , Giguère Patrick , Gravel Serge , Gagné Danièle , Goulet Anne-Christine , Fülöp Tamàs , Payet Marcel D , Dupuis Gilles
Published: September 2022

We have treated Jurkat T lymphocytes with a concentration (160 nM) of phorbol myristyl acetate (PMA) that down-regulates conventional and novel protein kinase C (PKC) isozymes and we have investigated the effects on Ca2+ signaling and protein tyrosine phosphorylation using mAb (C305) directed against the β-subunit of the Ti heterodimer or the ɛ/δ-component of the CD3 complex (mAb Leu 4 or OKT 3). The levels of expression of PKC α, βI, βII, and δ were reduced by 90% or more in PMA-treated cells, whereas the expression of PKCθ decreased by ∼30%. In contrast, the chronic treatment with PMA increased the expression of PKCɛ and PKCζ. There was a lack of Ca2+ response and myo-inositol trisphosphate (IP3) production in PMA-treated cells when they were exposed to mAb Leu 4 but the cells responded to mAb C305. The treatment with PMA did not affect the surface expression of Ti or CD3. The overall levels of tyrosine-phosphorylated proteins were markedly reduced in PMA-treated cells. We investigated whether these observations were related to defects in signal transduction related to protein tyrosine kinase (PTK) of the src and syk families. The electrophoretic mobilities of p59fyn or ZAP-70 were not changed in PMA-treated cells but p56Ick migrated as a large band of Mr 60–62 kDa. The decreased mobility of p56Ick was related to a state of hyperphosphorylation. The activity of modified p56Ick was not up-regulated in activated Jurkat cells. Our data suggest that clonotypic Ti can trigger Ca2+ mobilization independently of conventional PKC isoforms. Our observations further suggest that conventional PKC isoforms are involved early in the cascade of events associated with Jurkat T lymphocyte activation.
Induction of cyclooxygenase-2 expression during HIV-1-infected monocyte-derived macrophage and human brain microvascular endothelial cell interactions
Authors: Pereira Cândida F , Boven Leonie A , Middel Jeena , Verhoef Jan , Nottet Hans S L M
Published: September 2022

Human immunodeficiency virus type-1 (HIV-1)-associated dementia (HAD) is a neurodegenerative disease characterized by HIV infection and replication in brain tissue. HIV-1-infected monocytes overexpress inflammatory molecules that facilitate their entry into the brain. Prostanoids are lipid mediators of inflammation that result from cyclooxygenase-2 (COX-2) activity. Because COX-2 is normally induced during inflammatory processes, the aim of this study was to investigate whether COX-2 expression is up-regulated during monocyte-brain endothelium interactions. In vitro cocultures of HIV-infected macrophages and brain endothelium showed an up-regulation of COX-2 expression by both cell types. This up-regulation occurs via an interleukin-1β (IL-1β)-dependent mechanism in macrophages and via an IL-1β-independent mechanism in endothelial cells. Thus, interactions between HIV-infected monocytes and brain endothelium result in COX-2 expression and, as such, might contribute to the neuropathogenesis of HIV infection.
Primary macrophages infected by human immunodeficiency virus trigger CD95-mediated apoptosis of uninfected astrocytes
Authors: Aquaro Stefano , Panti Stefania , Caroleo Maria Cristina , Balestra Emanuela , Cenci Alessandra , Forbici Federica , Ippolito Giuseppe , Mastino Antonio , Testi Roberto , Mollace Vincenzo , Caliò Raffaele , Perno Carlo Federico
Published: September 2022

Infection of macrophages (M/M) by human immunodeficiency virus (HIV) is a main pathogenetic event leading to neuronal dysfunction and death in patients with AIDS dementia complex. Alteration of viability of neurons and astrocytes occurs in vivo even without their infection, thus it is conceivable that HIV-infected M/M may affect viability of such cells even without direct infection. To assess this hypothesis, we studied the effects of HIV-infected M/M on an astrocytic cell-line lacking CD4-receptor expression. Exposure to supernatants of HIV-infected M/M triggers complete disruption and apoptotic death of astrocytic cells. This effect is not related to HIV transmission from infected M/M, because HIV-DNA and p24 production in astrocytic cells remained negative. Apoptotic death of astrocytes is mainly mediated by Fas ligand released in supernatants of HIV-infected M/M (as demonstrated by complete reversal of such phenomenon by adding neutralizing antibodies against CD95 receptor). Treatment of astrocytic cells with recombinant (biologically active) Tat induces <10% apoptosis, and gp120 was totally ineffective. Treatment of HIV-infected M/M with AZT completely reverses the proapoptotic effect of their supernatants on astrocytes, thus demonstrating that productive virus replication within M/M is required for the induction of astrocytic cell death. Taken together, data suggest that homeostasis of astrocytes may be affected by HIV-infected M/M in the absence of productive infection of target cells. This phenomenon may help to explain the cellular damage found in HIV-infected patients also in areas of the brain not strictly adjacent to HIV-infected M/M.
The immunobiology and clinical potential of immunostimulatory CpG oligodeoxynucleotides
Authors: Weiner George J
Published: September 2022

Over 100 years ago, Coley first explored the use of bacterial products as immunostimulatory therapy for nonbacterial disease. It is now clear that bacterial DNA, and synthetic oligodeoxynucleotides containing specific motifs centered on a CpG dinucleotide (CpG ODN), are potent immunostimulatory agents. The molecular mechanisms responsible for the immunostimulatory effects of CpG ODN have yet to be elucidated fully, although it is clear that CpG ODN act rapidly on a variety of cell types. This includes activation of B cells, natural killer cells, and antigen-presenting cells including monocytes, macrophages, and dendritic cells. These effects have led to evaluation of CpG ODN as immune adjuvants in immunization where they have been shown in animal models to enhance the development of a TH1-type immune response. Preliminary results from clinical trials using CpG ODN as an immune adjuvant are promising. Preclinical studies suggest CpG ODN can also enhance innate immunity against a variety of infections, synergize with monoclonal antibody to enhance antibody-dependent cellular cytotoxicity, and alter the Th1/Th2 balance as a possible treatment for allergic diseases and asthma. Clinical evaluation has recently begun to determine whether promising preclinical results with CpG ODN can be translated into effective and tolerable clinical treatment approaches.
Functional consequences of FcɛRIα up-regulation by IgE in human basophils
Authors: MacGlashan Donald , Schroeder John T
Published: September 2022

These studies examine the functional changes that occur after up-regulation of FcɛRIα by immunoglobulin E (IgE) for human basophils. Basophils were cultured with and without IgE antibody (PS myeloma IgE or anti-gp120-specific IgE) for 1 week and challenged with anti-IgE, anti-FcɛRIα, or antigen for histamine and IL-4 secretion. There were no statistically significant changes in their response to anti-IgE or anti-receptor antibodies, as compared with controls incubated for the same period, whereas receptor expression increased an average of 4-fold. There was increased responsiveness to antigenic challenge, most notably at suboptimal concentrations of antigen (gp120 peptide-ovalbumin conjugate). For a 6-fold difference in cell surface density of gp120-specific IgE, there was a 2.2-fold change in antigen potency or 3-fold increases in histamine release at lower antigen concentrations. Similar results were found for secretion of IL-4. Basophil sensitivity, which is a measure of the density of antigen-specific IgE required for 50% of maximal secretion, was used to determine whether up-regulation of FcɛRIα was coordinated with up-regulation of other components of the IgE-signaling pathway. The results indicated up-regulation of FcɛRI is not always accompanied by changes that allow sensitivity to be maintained. These results indicate that functional up-regulation does occur but that its magnitude may be modulated because not all components of the signaling pathway are up-regulated in a balanced manner.
Escherichia coli cytotoxic necrotizing factor-1 (CNF-1) increases the adherence to epithelia and the oxidative burst of human polymorphonuclear leukocytes but decreases bacteria phagocytosis
Authors: Hofman Paul , Le Negrate Gaëlle , Mograbi Baharia , Hofman Véronique , Brest Patrick , Alliana-Schmid Annie , Flatau Gilles , Boquet Patrice , Rossi Bernard
Published: September 2022

Recruitment of polymorphonuclear leukocytes (PMNL) is a hallmark of both urinary and digestive infections caused byEscherichia coli. Cytotoxic necrotizing factor 1 (CNF-1) is a toxin produced by uropathogenic E. coli strains that mediates its effects via the activation of small GTP-binding proteins. However, the role and the consequences of CNF-1 on PMNL physiology remain largely unknown. In this study, we provide evidence that CNF-1 dramatically affects the PMNL cytoskeleton architecture by inducing an increased content of F-actin. Furthermore, we demonstrate that CNF-1 increases functional features of PMNL, such as superoxide generation and adherence on epithelial T84 monolayers, but significantly decreases their phagocytic function. Our results suggest that CNF-1 may behave as a virulence factor in urinary or digestive infection by stimulating PMNL cytotoxicity as a result of its enhancing effect on their adherence to epithelial cells as well as the production of radical oxygen products. Moreover, the decreased phagocytosis of PMNL induced by CNF-1 likely facilitates growth of bacteria. In these conditions, CNF-1 would intervene in the initiation and in the perpetuation of the inflammatory process.
Functional heterogeneity of rat hepatic and alveolar macrophages: effects of chronic ethanol administration
Authors: Morio Lisa A , Chiu Hawjyh , Sprowles Karen A , Laskin Debra L
Published: September 2022

Chronic ethanol consumption is associated with increased incidence of hepatic and pulmonary infections. To determine if this is correlated with altered macrophage activity, we analyzed the functional properties of cells isolated sequentially from the liver and lung of rats fed a liquid diet containing ethanol (35% of calories) or malto-dextrin control for 9–12 weeks. Hepatic and alveolar macrophages from control animals were found to exhibit distinct morphologic and functional properties. Thus, hepatic macrophages were highly vacuolated and appeared larger and more irregular in shape than alveolar macrophages. These cells also displayed greater phagocytic activity and random migration. In contrast, lung macrophages produced more superoxide anion and nitric oxide, and exhibited enhanced chemotactic activity toward the complement fragment C5a. Whereas administration of ethanol to rats for 9–12 weeks resulted in decreased chemotaxis and superoxide anion production by alveolar macrophages, cell adhesion molecule expression was reduced in hepatic macrophages. Nitric oxide production and inducible nitric oxide synthase protein expression were decreased in both macrophage populations. These effects were not observed after 3–6 weeks of ethanol administration to rats. Our results suggest that changes in macrophage functioning may play a role in decreased host defense following chronic ethanol exposure.
Tacrolimus (FK506) treatment of CD34+ hematopoietic progenitor cells promote the development of dendritic cells that drive CD4+ T cells toward Th2 responses
Authors: Shimizu Kanako , Fujii Shin-ichiro , Fujimoto Koji , Kawa Keisei , Yamada Akira , Kawano Fumio
Published: September 2022

The macrolide lactone, tacrolimus (FK506), is utilized in bone marrow transplantation (BMT) to prevent graft-versus-host disease (GVHD). In the current study, we evaluated the ability of FK506 to modify the function of dendritic cells (DCs) derived from CD34+ hematopoietic progenitor cells (HPCs). Comparable to DCs obtained in the absence of FK506, DCs cultured in the presence of FK506 (FK-DCs) had higher expression of CD1a+ and formed a greater number of DC colonies. Despite the same expression of costimulatory molecules, FK-DCs displayed a reduced capacity to stimulate an allogeneic T cell response, and showed significantly lower interleukin (IL)-12 production. While normal DCs pulsed with the exogenous antigen, keyhole limpet hemocyanin (KLH) induced specific Th1-like interferon-γ(IFN-γ) producing CD4+ T cell line, FK-DCs induced Th2-like interleukin-4 (IL-4) producing CD4+ T cell line. These data demonstrate the ability of FK506 to induce Th2-promoting function in developing DCs.
C5a-stimulated human neutrophils use a subset of β2 integrins to support the adhesion-dependent phase of superoxide production
Authors: Tyagi ShivRaj , Klickstein Lloyd B , Nicholson-Weller Anne
Published: September 2022

Isolated human polymorphonuclear neutrophils (PMN) responded to human C5a with an immediate, transient release of superoxide lasting from 0.5 to 5 min. This was followed by a second release of superoxide, which began at 10 min after addition of C5a, was sustained for more than 30 min, and required ICAM-1 immobilized in the wells. F(ab′)2 monoclonal antibody (mAb) preparations were used to dissect the role of individual β2 integrins and to avoid the confounding effects of ligating Fc receptors. Anti-CD18 mAb treatment of the PMN had no effect on the immediate first phase but completely inhibited the second, adhesion-dependent phase of superoxide production. Anti-CR3 mAb only inhibited the adhesion phase of superoxide production partially, implying that other β2 integrins were involved. A mixture of anti-CD11a, anti-CD11b, and anti-CD11c was not able to block superoxide production completely, suggesting a role for αd/β2. Surprisingly, blocking anti-LFA-1 mAb had no effect on superoxide production. Consistent with this observation, immobilized, purified ICAM-2, a specific counter-receptor for LFA-1, did not support the adhesion-dependent phase ofsuperoxide production. Thus, PMN treated with C5a used signals via CR3, P150/95, and αd/β2, but not LFA-1, to support superoxide production. LFA-1 has been shown by others to mediate most of the adhesion necessary for transendothelial migration in vivo. The inability of LFA-1 ligation to stimulate superoxide production may be an important means of preventing blood-vessel damage when PMN migrate across the endothelium.
Differential expression of heat shock protein 70 (hsp70) in human monocytes rendered apoptotic by IL-4 or serum deprivation
Authors: Lang Detlef , Hubrich Andreas , Dohle Frank , Terstesse Martin , Saleh Hilmi , Schmidt Michael , Pauels Hans-Gerd , Heidenreich Stefan
Published: September 2022

Apoptosis of monocytes is regulated by the balance between pro- and antiapoptotic triggers and pathways and may strongly influence inflammatory disorders. The major heat shock protein, hsp70, is an effective inhibitor of apoptosis in lymphocytic and monocytic tumor cell lines, but the implications in the regulation of apoptosis of freshly isolated human monocytes have not been elucidated. In this study, we examined whether two different triggers of monocyte apoptosis, serum deprivation and IL-4, respectively, altered hsp70 expression and whether expression levels correlated with monocyte survival. Monocyte apoptosis was determined quantitatively by flow cytometry detecting annexin V binding or nuclear stainability with propidium iodide (PI). Hsp70 expression was analyzed by semiquantitative RT-PCR and immunoblotting. Exposing monocytes to heat shock (47°C, 20 min) induced a rapid and marked upregulation of hsp70 without evoking injury or apoptosis, suggesting that hsp70 conferred protection and survival. In accordance, when monocytes were rendered apoptotic by serum deprivation, a drastic downregulation of hsp70 occurred, which was accompanied by a reduced synthesis of the constitutive family member hsc70. However, induction of monocyte apoptosis by IL-4 increased hsp70 expression in a concentration and time-dependent fashion. A neutralizing antibody against IL-4 abolished hsp70 expression and apoptosis induction after IL-4 treatment and so excluded indirect effects. LPS rescued monocytes from apoptosis but did not alter hsp70 formation significantly. These findings suggest that, in monocytes, distinct apoptotic triggers induce different responses of hsp70 so that this molecule does not exert protection against cell death directly or in general.
Selective stimulation of G-CSF gene expression in macrophages by a stimulatory monoclonal antibody as detected by a luciferase reporter gene assay
Authors: Aoki Yoshiko , Sha Shiken , Mukai Hidehito , Nishi Yoshisuke
Published: September 2022

We have identified a stimulatory monoclonal antibody (mAb) from autoimmune mice that selectively stimulates granulocyte colony-stimulating factor (G-CSF) gene expression in a mouse macrophage cell line. The induction was observed not only in the cell line, but also in normal peritoneal macrophages. This mAb bound to the monocyte/macrophage cell lines and pre-B leukemia cell lines, but also in normal peritoneal macrophages, whereas it did not bind to normal T and B cells in the spleen or fibroblastic cell lines. It could even bind to a human promyelocytic leukemia cell line, when they were differentiated into monocytic cells. On Western blotting, this mAb mainly recognized an approximately 30-kDa band and it was unique because there have been no reports of membrane-associated proteins with a similar molecular mass found in macrophages. These results suggest that there could be a specific gateway molecule to induce G-CSF in macrophages.
DNA vaccination: antigen presentation and the induction of immunity
Authors: Shedlock Devon J , Weiner David B
Published: September 2022

DNA vaccination, or genetic immunization, is a novel vaccine technology that has great potential for reducing infectious disease and cancer-induced morbidity and mortality worldwide. Since their inception, DNA vaccines have been used to stimulate protective immunity against many infectious pathogens, malignancies, and autoimmune disorders in animal models. Plasmid DNA encoding a polypeptide protein antigen is introduced into a host where it enters host cells and serves as an epigenetic template for the high-efficiency translation of its antigen. An immune response, which is mediated by the cellular and/or humoral arms of the immune system and is specific for the plasmid-encoded antigen, ensues. It is thought that “professional” antigen-presenting cells play a dominant role in the induction of immunity by presenting vaccine peptides on MHC class I molecules, following direct transfection or “cross”-presentation, and MHC class II molecules after antigen capture and processing within the endocytic pathway. The correlates of immunity can be manipulated according to many immunization parameters, including the method of vaccine delivery, presence of genetic adjuvants, and vaccine regimen. DNA vaccines first advanced to the clinic five years ago, and the initial picture of their utility in humans is emerging. However, further analysis is required to determine their ultimate efficacy and safety in human beings. This technology has acquired a strong foothold in the field of experimental immunotherapy, and it is hoped that it will eventually represent the next generation of prophylactic and therapeutic vaccines.
Activation of human neutrophils by the plant lectinViscum albumagglutinin-I: modulation ofde novoprotein synthesis and evidence that caspases are involved in induction of apoptosis
Authors: Savoie Anik , Lavastre Valérie , Pelletier Martin , Hajto Tibor , Hostanska Katarina , Girard Denis
Published: September 2022

The plant lectin Viscum album agglutinin-I (VAA-I) was recently found to modulate protein synthesis and to induce apoptosis in various cells of immune origin. We found that VAA-I induces de novo protein synthesis of metabolically 35S-labeled human neutrophils when used at low concentrations (<100 ng/mL) but acts as an inhibitor at higher concentrations. Using both flow cytometry (FITC-Annexin-V/PI labeling) and cytology (Diff-Quick staining) approaches, we found that VAA-I could not modulate neutrophil apoptosis at low concentrations but could induce it in >98% of cells at 500 and 1000 ng/mL. VAA-I was also found to reverse the delaying effect of GM-CSF on neutrophil apoptosis and to inhibit GM-CSF-inducedde novo protein synthesis. In contrast to GM-CSF, VAA-I does not induce tyrosine phosphorylation by itself and does not alter the GM-CSF-induced response. Among the inhibitors used, genistein, pertussis toxin, staurosporine, H7, Calphostin C, manoalide, BpB, quinacrine HA-1077, and z-VAD-FMK, only the latter (inhibitor of caspases-1, -3, -4, and -7) was found to inhibit VAA-I-induced neutrophil apoptosis as the percentage of apoptotic cells decrease from 98 ± 1.3 to 54 ± 3.2% (n =4). Furthermore, we confirm that caspases are involved in VAA-I-induced neutrophil apoptosis as we have observed the fragmentation of the cytoskeletal gelsolin protein that is known to be caspase-3-dependent. Such degradation was reversed by the z-VAD-FMK inhibitor. We conclude that induction of neutrophil apoptosis by VAA-I is a caspase-dependent mechanism that does not involve tyrosine phosphorylation events, G-proteins, PKCs, and PLA2. In addition, we conclude that at least caspase-3 is involved. Correlation between VAA-I-induced neutrophil apoptosis and VAA-I-induced inhibition of de novo protein synthesis is discussed.
Spontaneous apoptosis in neutrophils is associated with downregulation of HLA Class I and is prevented by ligation of Class I
Authors: Frumento Guido , Ottonello Luciano , Bertolotto Maria , Franchello Silvia , Melioli Giovanni , Dallegri Franco
Published: September 2022

In many types of cells, ligation of human leukocyte antigens (HLA) Class I molecules with specific mAbs results in the transduction of signals that trigger different cell functions. We have investigated the effects of Class I ligation in human neutrophils. After several hours in culture, neutrophils split spontaneously into two subpopulations, one with normal and the other with reduced levels of Class I. The latter subpopulation displayed high binding capacity for Annexin V, showed a hypodiploid peak, electrophoretic DNA fragmentation, and morphological features of apoptotic cells. The addition of drugs known to delay apoptosis (GM-CSF or cAMP) resulted in a reduction of Class I modulation. Furthermore, ligation of surface Class I with F(ab′)2 fragments of the anti-Class I mAb W6/32 resulted in a delay in the progression of apoptosis. These data indicate that this surface Class I molecule is a marker of age-related apoptosis, and the ligation of these molecules results in the transduction of a signal that inhibits apoptosis. Thus, the downregulation of HLA Class I molecules in aging neutrophils prevents their halting the apoptotic process.
Monocytes adhering by LFA-1 to placental syncytiotrophoblasts induce local apoptosis via release of TNF-α. A model for hematogenous initiation of placental inflammations
Authors: Garcia-Lloret Maria I , Winkler-Lowen Bonnie , Guilbert Larry J
Published: September 2022

Placental inflammations (villitis) are accompanied by loss of the syncytiotrophoblast, which is the cellular barrier separating maternal blood from fetal tissue in the villous placenta. We propose that syncytiotrophoblast loss is mediated by adhesion of activated maternal monocytes. This hypothesis was tested with a co-culture model of peripheral blood monocytes and placental syncytiotrophoblasts. We find that LPS-activated monocytes adhere to interferon-γ (IFN-γ)-treated syncytiotrophoblasts via monocyte LFA-1 for >48 h, during which time the monocytes induce trophoblast apoptosis and subsequent damage of the trophoblast layer. Optimal monocyte-mediated syncytiotrophoblast death requires both lipopolysaccharide (LPS) and IFN-γ and is inhibited by either anti-tumor necrosis factor (TNF) antibody or epidermal growth factor. Syncytiotrophoblast damage is largely limited to culture surfaces in the vicinity of bound monocytes. These results show that activated maternal monocytes bound to the placental barrier can induce focal damage mediated by the inflammatory cytokine TNF-α and suggest a route for maternal leukocyte infiltration into the fetal stroma.
Transcriptional activation of the gp91phoxNADPH oxidase subunit by TPA in HL-60 cells
Authors: Samuelson David J , Powell Marianne-B , Lluria-Prevatt Maria , Romagnolo Donato F
Published: September 2022

The exposure to epigenetic effectors capable of inducing copious production of reactive oxygen species (ROS) has been associated with chronic inflammation, tumor initiation, and promotion. The objective of this study was to examine the regulation of gp91phox, the catalytic subunit of the NADPH oxidase, and the kinetics of ROS production in promyelocytic leukemia HL-60 cells induced with 12-O-tetradeconylphorbol-13-acetate (TPA). The treatment of HL-60 cells with TPA (0.1 μM) induced cellular differentiation, which was followed after 48 h by a tenfold increase in chemiluminescence from lucigenin and a 2.5-fold increase in the intracellular oxidation of 2′,7′-dicholorofluorescin (DCFH). Whereas higher concentrations (1.0 μM) of TPA did not stimulate further ROS production, repeated stimulation with 0.1 μM TPA of differentiated cells induced a modest (1.2-fold) but rapid (15 min) increase in chemiluminescence. In cells treated with TPA, the burst in ROS at 48 h was preceded by accumulation at 12 h of gp91phox (8.8-fold) and p47phox mRNA (threefold), whereas untreated cells contained steady-state levels of both transcripts. Time-course experiments with actinomycin D to inhibit transcription revealed that TPA did not improve the stability of gp91phox. In transient transfections, luciferase reporter activity directed from a 1.5-kb gp91phox promoter fragment was enhanced threefold upon treatment with TPA for 24 h. We conclude that TPA can commit HL-60 cells to differentiation and elicit transcription from the proximal gp91phox promoter.