Single-cell sequencing analysis and multiple machine-learning models revealed the cellular crosstalk of dendritic cells and identified FABP5 and KLRB1 as novel biomarkers for psoriasis

Background

Psoriasis is an immune-mediated disorder influenced by environmental factors on a genetic basis. Despite advancements, challenges persist, including the diminishing efficacy of biologics and small-molecule targeted agents, alongside managing recurrence and psoriasis-related comorbidities. Unraveling the underlying pathogenesis and identifying valuable biomarkers remain pivotal for diagnosing and treating psoriasis.

Methods

We employed a series of bioinformatics (including single-cell sequencing data analysis and machine learning techniques) and statistical methods to integrate and analyze multi-level data. We observed the cellular changes in psoriatic skin tissues, screened the key genes Fatty acid binding protein 5 (FABP5) and The killer cell lectin-like receptor B1 (KLRB1), evaluated the efficacy of six widely prescribed drugs on psoriasis treatment in modulating the dendritic cell-associated pathway, and assessed their overall efficacy. Finally, RT-qPCR, immunohistochemistry, and immunofluorescence assays were used to validate.

Results

The regulatory influence of dendritic cells (DCs) on T cells through the CD70/CD27 signaling pathway may emerge as a significant facet of the inflammatory response in psoriasis. Notably, FABP5 and KLRB1 exhibited up-regulation and co-localization in psoriatic skin tissues and M5-induced HaCaT cells, serving as potential biomarkers influencing psoriasis development.

Conclusion

Our study analyzed the impact of DC-T cell crosstalk in psoriasis, elucidated the characterization of two biomarkers, FABP5 and KLRB1, in psoriasis, and highlighted the promise and value of tofacitinib in psoriasis therapy targeting DCs.

Sevoflurane Preconditioning Alleviates Posttraumatic Stress Disorder-Induced Apoptosis in the Hippocampus via the EZH2-Regulated Akt/mTOR Axis and Improves Synaptic Plasticity

Posttraumatic stress disorder (PTSD) is a persistent and severe psychological and mental disorder resulting from experiences of serious trauma or stress and is suffered by many individuals. Previous studies have shown that pretreatment with sevoflurane is efficient in reducing the incidence of PTSD. However, we require a more comprehensive understanding of the specific mechanisms by which sevoflurane works. Enhancer of zeste homolog 2 (EZH2) has been reported to be regulated by sevoflurane, and to improve patient cognition. In this study, we aimed to explore the mechanisms of sevoflurane and the role of EZH2 in PTSD cases. We explored the effects of sevoflurane and EPZ-6438 (inhibitor of EZH2) on rat behavior, followed by an investigation of EZH2 mRNA and protein expression. The effects of sevoflurane and EZH2 on neuronal survival were assessed by western blotting and TUNEL staining, while western blotting was used to examine the expression of PSD95 and the AKT/mTOR proteins. Sevoflurane preconditioning restored EZH2 expression and significantly inhibited apoptosis by regulating phosphorylation of the AKT/mTOR pathway. Synaptic plasticity was also significantly improved. These results suggest that pretreatment with sevoflurane could play an important role in PTSD prevention by regulating EZH2 expression.

Sp1 Controls the Basal Level of Interleukin-34 Transcription

Interleukin-34 (IL-34) is a cytokine that plays important roles at steady state and in diseases. The induced or inhibited expression of IL-34 by stimuli has been deeply investigated. However, the regulation of IL-34 basal expression is largely unknown. The aim of this study is to investigate whether IL-34 expression is regulated by a general transcription factor Specificity Protein 1 (Sp1) at transcription level. By using bioinformatic software, four putative Sp1-binding sites overlapping GC boxes were found in the core promoter region of IL-34. Alignment of the core promoter sequences of mammalian IL-34 showed GC box-C (-62/-57) and D (-11/-6) were conserved in some mammals. Luciferase assay results showed that only deletion of GC box-C (-62/-57) significantly reduced luciferase activities of IL-34 core promoter in SH-SY5Y cells. By using electrophoretic mobility shift assay (EMSA), it was found that Sp1 specifically interacted with GC box-C sequence CCCGCC (-62/-57) in the core promoter of IL-34. By using chromatin immunoprecipitation (ChIP), it was discovered that Sp1 bound to the core promoter of IL-34 in living cells. In addition, silencing of Sp1 expression by its specific siRNA reduced IL-34 mRNA and protein levels significantly in SH-SY5Y cells. Likewise, IL-34 expression was inhibited in a dose-dependent manner by a Sp1 inhibitor Plicamycin. Furthermore, silencing of Sp1 also downregulated mRNA and protein expression of IL-34 in GES-1 and 293T cell lines, suggesting that IL-34 transcription regulated by Sp1 was not cell-type specific. Taken together, these results indicate that Sp1 controls the basal level of IL-34 transcription.

Highly robust causal semiparametric U-statistic with applications in biomedical studies

With our increased ability to capture large data, causal inference has received renewed attention and is playing an ever-important role in biomedicine and economics. However, one major methodological hurdle is that existing methods rely on many unverifiable model assumptions. Thus robust modeling is a critically important approach complementary to sensitivity analysis, where it compares results under various model assumptions. The more robust a method is with respect to model assumptions, the more worthy it is. The doubly robust estimator (DRE) is a significant advance in this direction. However, in practice, many outcome measures are functionals of multiple distributions, and so are the associated estimands, which can only be estimated via U-statistics. Thus most existing DREs do not apply. This article proposes a broad class of highly robust U-statistic estimators (HREs), which use semiparametric specifications for both the propensity score and outcome models in constructing the U-statistic. Thus, the HRE is more robust than the existing DREs. We derive comprehensive asymptotic properties of the proposed estimators and perform extensive simulation studies to evaluate their finite sample performance and compare them with the corresponding parametric U-statistics and the naive estimators, which show significant advantages. Then we apply the method to analyze a clinical trial from the AIDS Clinical Trials Group.

Gut metagenomic characteristics of ADHD reveal low Bacteroides ovatus-associated host cognitive impairment

Attention-deficit/hyperactivity disorder (ADHD) is a highly heterogeneous psychiatric disorder that can have three phenotypical presentations: inattentive (I-ADHD), hyperactive-impulsive (HI-ADHD), and combined (C-ADHD). Environmental factors correlated with the gut microbiota community have been implicated in the development of ADHD. However, whether different ADHD symptomatic presentations are associated with distinct microbiota compositions and whether patients could benefit from the correction of aberrant bacterial colonization are still largely unclear. We carried out metagenomic shotgun analysis with 207 human fecal samples to characterize the gut microbial profiles of patients with ADHD grouped according to their phenotypical presentation. Then, we transplanted the candidate low-abundance bacteria identified in patient subgroups into ADHD rats and evaluated ADHD-associated behaviors and neuronal activation in these rats. Patients with C-ADHD had a different gut microbial composition from that of healthy controls (HCs) (p = .02), but not from that of I-ADHD patients. Eight species became progressively attenuated or enriched when comparing the compositions of HCs to those of I-ADHD and C-ADHD; in particular, the abundance of Bacteroides ovatus was depleted in patients with C-ADHD. In turn, Bacteroides ovatus supplementation ameliorated spatial working memory deficits and reversed θ electroencephalogram rhythm alterations in ADHD rats. In addition, Bacteroides ovatus induced enhanced neuronal activation in the hippocampal CA1 subregion. These findings indicate that gut microbial characteristics that are unique to patients with C-ADHD may be masked when considering a more heterogeneous group of patients. We link the gut microbiota to brain function in an ADHD animal model, suggesting the relevance of testing a potential bacteria-based intervention for some aspects of ADHD.

DNA Holliday Junction: History, Regulation and Bioactivity

DNA Holliday junction (HJ) is a four-way stranded DNA intermediate that formed in replication fork regression, homology-dependent repair and mitosis, performing a significant role in genomic stability. Failure to remove HJ can induce an acceptable replication fork stalling and DNA damage in normal cells, leading to a serious chromosomal aberration and even cell death in HJ nuclease-deficient tumor cells. Thus, HJ is becoming an attractive target in cancer therapy. However, the development of HJ-targeting ligand faces great challenges because of flexile cavities on the center of HJs. This review introduces the discovery history of HJ, elucidates the formation and dissociation procedures of HJ in corresponding bio-events, emphasizes the importance of prompt HJ-removing in genome stability, and summarizes recent advances in HJ-based ligand discovery. Our review indicate that target HJ is a promising approach in oncotherapy.

Establishment of a Cre-loxP System Based on a Leaky LAC4 Promoter and an Unstable panARS Element in Kluyveromyces marxianus

The Cre-loxP system produces structural variations, such as deletion, duplication, inversion and translocation, at specific loci and induces chromosomal rearrangements in the genome. To achieve chromosomal rearrangements in Kluyveromyces marxianus, the positions and sequences of centromeres were identified in this species for the first time. Next, a Cre-loxP system was established in K. marxianus. In this system, the Cre recombinase was expressed from a leaky LAC4 promoter in a plasmid to alleviate the cytotoxicity of Cre, and the unstable plasmid contained a panARS element to facilitate the clearance of the plasmid from the cells. By using LAC4 as a reporter gene, the recombination frequencies between loxP sites or loxPsym sites were 99% and 73%, respectively. A K. marxianus strain containing 16 loxPsym sites in the genome was constructed. The recombination frequency of large-scale chromosomal rearrangements between 16 loxPsym sites was up to 38.9%. Our study provides valuable information and tools for studying chromosomal structures and functions in K. marxianus.

Characterization and optimization of the LAC4 upstream region for low-leakage expression in Kluyveromyces marxianus

Kluyveromyces marxianus is a promising host for the production of heterologous proteins, chemicals, and bioethanol. One superior feature of this species is its capacity to assimilate lactose, which is rendered by the LAC12-LAC4 gene pair encoding a lactose permease and a β-galactosidase enzyme. Little is known about the regulation of LAC4 in K. marxianus. In this study, we showed the presence of weak glucose repression in the regulation of LAC4 and that might contribute to the leaky expression of LAC4 in the glucose medium. In a mutagenesis screen of 1000-bp LAC4 upstream region, one mutant region, named H1, drove low-leakage expression of a URA3 reporter gene in glucose medium. Two mutations inside a polyadenosine stretch (poly(A)) of 5' UTR were major contributors to the low-leakage phenotype of H1. H1 directed low-leakage expression of GFP on a plasmid and that of LAC4 in situ in the glucose medium, which was not due to the reduction of mRNA levels. Meanwhile, H1 did not affect the induction of GFP or LAC4 by lactose. Cre recombinase expressed by H1 caused lower toxicity in the repressive condition and achieved higher yield after induction, compared with that expressed by a wild-type LAC4 upstream region or a strong INU1 promoter. Our study suggested that poly(A) inside 5' UTR played a role in regulating the expression of LAC4 in the repressive condition. Meanwhile, H1 provided a base for the development of a strict inducible system for expressing industrial proteins, especially toxic proteins.

Activation of astroglial CB1R mediates cerebral ischemic tolerance induced by electroacupuncture

There are no effective treatments for stroke. The activation of endogenous protective mechanisms is a promising therapeutic approach, which evokes the intrinsic ability of the brain to protect itself. Accumulated evidence strongly suggests that electroacupuncture (EA) pretreatment induces rapid tolerance to cerebral ischemia. With regard to mechanisms underlying ischemic tolerance induced by EA, many molecules and signaling pathways are involved, such as the endocannabinoid system, although the exact mechanisms have not been fully elucidated. In the current study, we employed mutant mice, neuropharmacology, microdialysis, and virus transfection techniques in a middle cerebral artery occlusion (MCAO) model to explore the cell-specific and brain region-specific mechanisms of EA-induced neuroprotection. EA pretreatment resulted in increased ambient endocannabinoid (eCB) levels and subsequent activation of ischemic penumbral astroglial cannabinoid type 1 receptors (CB₁R) which led to moderate upregulation of extracellular glutamate that protected neurons from cerebral ischemic injury. These findings provide a novel cellular mechanism of EA and a potential therapeutic target for ischemic stroke.

FAM96A knock-out promotes alternative macrophage polarization and protects mice against sepsis

Sepsis is an intractable clinical syndrome characterized by organ dysfunction when the body over-responds to an infection. Sepsis has a high fatality rate and lacks effective treatment. Family with sequence similarity 96 member A (FAM96A) is an evolutionarily conserved protein with high expression in the immune system and is related to cytosolic iron assembly and tumour suppression; however, research has been rarely conducted on its immune functions. Our study found that Fam96a-/- mice significantly resisted lesions during sepsis simulated by caecal ligation and puncture (CLP) or endotoxicosis models. After a challenge with lipopolysaccharide (LPS) or infection, Fam96a-/- mice exhibited less organ damage, longer survival and better bacterial clearance with decreased levels of proinflammatory cytokines. While screening several subsets of immune cells, FAM96A-expressing macrophages as the key cell type inhibited sepsis development. In-vivo macrophage depletion or adoptive transfer experiments abrogated significant differences in the survival of sepsis between Fam96a-/- and wild-type mice. Results of the bone marrow-derived macrophage (BMDM) polarization experiment indicated that FAM96A deficiency promotes the transformation of uncommitted monocytes/macrophages (M0) into M2 macrophages, secreting fewer proinflammatory cytokines. FAM96A may mediate an immunometabolism shift - from oxidative phosphorylation (OXPHOS) to glycolysis - in macrophages during sepsis, mirrored by reactive oxygen species (ROS) and glucose uptake. These data demonstrate that FAM96A regulates inflammatory response and provide a novel genomic insight for sepsis treatment.

Astroglial N-myc downstream-regulated gene 2 protects the brain from cerebral edema induced by stroke

Brain edema is a grave complication of brain ischemia and is the main cause of herniation and death. Although astrocytic swelling is the main contributor to cytotoxic edema, the molecular mechanism involved in this process remains elusive. N‐myc downstream‐regulated gene 2 (NDRG2), a well‐studied tumor suppressor gene, is mainly expressed in astrocytes in mammalian brains. Here, we found that NDRG2 deficiency leads to worsened cerebral edema, imbalanced Na⁺ transfer, and astrocyte swelling after ischemia. We also found that NDRG2 deletion in astrocytes dramatically changed the expression and distribution of aquaporin‐4 and Na⁺‐K⁺‐ATPase β1, which are strongly associated with cell polarity, in the ischemic brain. Brain edema and astrocyte swelling were significantly alleviated by rescuing the expression of astrocytic Na⁺‐K⁺‐ATPase β1 in NDRG2‐knockout mouse brains. In addition, the upregulation of astrocytic NDRG2 by lentiviral constructs notably attenuated brain edema, astrocytic swelling, and blood–brain barrier destruction. Our results indicate a particular role of NDRG2 in maintaining astrocytic polarization to facilitate Na⁺ and water transfer balance and to protect the brain from ischemic edema. These findings provide insight into NDRG2 as a therapeutic target in cerebral edema.

Noninvasive prenatal diagnosis for pregnancies at risk for β-thalassaemia: a retrospective study

OBJECTIVE

To evaluate the clinical feasibility of noninvasive prenatal diagnosis (NIPD) for β-thalassaemia using circulating single molecule amplification and re-sequencing technology (cSMART).

DESIGN

Through carrier screening, 102 pregnant Chinese couples carrying pathogenic HBB gene variants were recruited to the study. Pregnancies were managed using traditional invasive prenatal diagnosis (IPD). Retrospectively, we evaluated the archived pregnancy plasma DNA by NIPD to evaluate the performance of our cSMART assay for fetal genotyping.

SETTING

Chinese prenatal diagnostic centres specialising in thalassaemia testing.

POPULATION

Chinese carrier couples at high genetic risk for β-thalassaemia.

METHODS

Fetal cell sampling was performed by amniocentesis and HBB genotypes were determined by reverse dot blot. NIPD was performed by a newly designed HBB cSMART assay and fetal genotypes were called by measuring the allelic ratios in the maternal cell-free DNA.

MAIN OUTCOME MEASURES

Concordance of HBB fetal genotyping between IPD and NIPD and the sensitivity and specificity of NIPD.

RESULTS

Invasive prenatal diagnosis identified 29 affected homozygotes or compound heterozygotes, 54 heterozygotes and 19 normal homozygotes. Compared with IPD results, 99 of 102 fetuses (97%) were correctly genotyped by our NIPD assay. Two of three discordant samples were false positives and the other sample involved an incorrect call of a heterozygote carrier as a homozygote normal. Overall, the sensitivity and specificity of our NIPD assay was 100% (95% CI 88.06-100.00%) and 97.26% (95% CI 90.45-99.67%), respectively.

CONCLUSIONS

This study demonstrates that our cSMART-based NIPD assay for β-thalassaemia has potential clinical utility as an alternative to IPD for pregnant HBB carrier couples.

TWEETABLE ABSTRACT

A new noninvasive test for pregnancies at risk for β-thalassaemia.

Glycogenolysis Is Crucial for Astrocytic Glycogen Accumulation and Brain Damage after Reperfusion in Ischemic Stroke

Astrocytic glycogen is an important energy reserve in the brain and is believed to supply fuel during energy crisis. However, the pattern of glycogen metabolism in ischemic stroke and its potential therapeutic impact on neurological outcomes are still unknown. Here, we found extensive brain glycogen accumulation after reperfusion in ischemic stroke patients and primates. Glycogenolytic dysfunction in astrocytes is responsible for glycogen accumulation, caused by inactivation of the protein kinase A (PKA)-glycogen phosphorylase kinase (PhK)-glycogen phosphorylase (GP) cascade accompanied by the activation of glycogen synthase kinase-3β (GSK3β). Genetic or pharmacological augmentation of astrocytic GP could promote astrocyte and neuron survival and improve neurological behaviors. In addition, we found that insulin exerted a neuroprotective effect, at least in part by rescuing the PKA-PhK-GP cascade to maintain homeostasis of glycogen metabolism during reperfusion. Together, our findings suggest a promising intervention for undesirable outcomes in ischemic stroke.

N-myc downstream-regulated gene 2 deficiency aggravates memory impairment in Alzheimer's disease

Alzheimer's disease (AD) is a chronic degenerative disease of the central nervous system and the most common dementia type in elderly people. N-myc downstream-regulated gene 2 (NDRG2), a cell stress response gene, is primarily expressed in astrocytes in mammalian brains. The hippocampal protein levels of NDRG2 in AD patients were significantly higher than those in healthy peers. However, whether the increase in NDRG2 is involved in the development of AD or is an endogenous protective response initiated by stress remains unknown. Here, we investigated the roles of NDRG2 in the development of memory impairment in AD using mouse models established by amyloid β injection or crossing of APP/PS1 mice. We found that NDRG2 deficiency worsened the memory impairment in AD mice. In addition, NDRG2 deletion induced downregulation of the proteasome functional subunit PSMB6 in AD mice. These findings suggest that NDRG2 is an endogenous neuroprotectant that participates in the pathological course of waste-clearing impairment and memory damage in AD. NDRG2 may be a therapeutic target for the intervention of AD memory degradation.

NDRG2 Protects the Brain from Excitotoxicity by Facilitating Interstitial Glutamate Uptake

Glutamate is a prominent neurotransmitter responsible for excitatory synaptic transmission and is taken up by sodium-dependent excitatory amino acid transporters (EAATs) on astrocytes to maintain synaptic homeostasis. Here, we report that N-myc downstream regulated gene 2 (NDRG2), a known tumor suppressor, is required to facilitate astroglial glutamate uptake and protect the brain from glutamate excitotoxicity after ischemia. NDRG2 knockout (Ndrg2^-/-) mice exhibited an increase in cerebral interstitial glutamate and a reduction in glutamate uptake into astrocytes. The ability of NDRG2 to control EAAT-mediated glutamate uptake into astrocytes required NDRG2 to interact with and promote the function of Na⁺/K⁺-ATPase β1, which could be disrupted by a Na⁺/K⁺-ATPase β1 peptide. The deletion of NDRG2 or treatment with the Na⁺/K⁺-ATPase β1 peptide significantly increased neuronal death upon a glutamate challenge and aggravated brain damage after ischemia. Our findings demonstrate that NDRG2 plays a pivotal role in promoting astroglial glutamate uptake from the interstitial space and protecting the brain from glutamate excitotoxicity.

Publication rate of registered clinical trials in lung cancer

e18211

Background: Clinical trials play a crucial role in shaping oncology practice. Publishing results of clinical trials is key to reducing publication bias. Lung cancer is the leading cause of cancer-related mortality in the U.S. We assessed the publication rate of registered lung cancer clinical trials. Methods: ClinicalTrials.gov was searched to identify registered lung cancer clinical trials with study completion date between 1/1/2000 and 8/7/2016. Interventional phase II and III clinical trials involving patients ³ 18 years old with a recruitment status of completed or terminated were included. Using National Clinical Trial identifier and keywords including the clinical trial name, three databases (PubMed, Google Scholar, EMBASE) were queried to assess the publication status of each trial. We analyzed the publication rate among the identified clinical trials and predictors of publication. Results: A total of 1293 clinical trials were identified. Among 1037 completed clinical trials, 690 (66.5%; 193,587 patients) were published in peer-reviewed journal, while 347 (33.5%; 51,505 patients) were unpublished. Industry sponsored, non-randomized, and single-center studies were less likely to be published with odds ratio 0.52 (95% CI: 0.28-0.97), 0.67 (0.45-1.00), and 0.36 (0.25-0.51), respectively. Among the 347 unpublished completed trials, 75 (21.6%) trials reported the results as meeting presentation and 63 (18.2%) trials posted the results only on ClinicalTrials.gov. Among 256 terminated clinical trials, 72 (28.1%; 19,858 patients) were published in peer-reviewed journal, while 184 (71.9%; 10,259 patients) were unpublished. Among the 184 unpublished terminated trials, 19 (10.3%) trials reported the results as meeting presentation and 70 (38.0%) trials posted the study results only on ClinicalTrials.gov; reporting of primary outcome was incomplete in 50 (71.4%) of 70 studies whose results were only available on ClinicalTrials.gov. Conclusions: A significant proportion of registered lung cancer clinical trials remain unpublished, raising the concern of publication bias in the field of thoracic oncology.

Abstract WP500: Stroke Transitions of Care Coordination Program is Feasible and May Reduce 30-day Readmissions

Introduction: Transitions of care from the acute hospital to other medical facilities and home is a national health care priority. We designed a randomized pilot study to assess the feasibility of a Transitions of Care Coordinator (TOCC) program led by a nurse navigator. We hypothesized that the navigator would complete all portions of TOCC program in at least 75% of acute ischemic stroke (AIS) pts.

Methods: Consecutive AIS patients admitted from April to July 2018 were randomized to TOCC group or usual care group. Pts discharged to subacute rehab, nursing home and hospice or died during hospitalization were excluded. In TOCC, the navigator met patient/caregiver on admission, followed up discharge pending diagnostics, attended multi-disciplinary rounds, facilitated rehab referrals, provided stroke education, and arranged clinic follow-up. Demographics, NIHSS, mRS and discharge disposition were collected. Hospital length of stay (LOS) was calculated from date/time of patient registration to discharge. Patient satisfaction questionnaire and readmission rate was assessed at 30 days by phone. Continuous variables were analyzed using Wilcoxon rank-sum and categorical variables using Fisher’s exact test.

Results: TOCC pts were older, but other demographics were well matched (table 1). The navigator completed all portions of the TOCC program in 80% of pts. The mean time spent by the navigator per TOCC pt was 111 minutes (SD 23). There was no difference in distribution of LOS between the TOCC and usual care groups (5.7 vs. 5.1 days, p=0.51). There was no difference in the mean patient satisfaction scores between TOCC and usual care groups (30.3 vs. 29.6, p=0.66). There were no 30-day readmissions or ER visits in TOCC group vs. 3 and 2 in the usual care (p=0.25, p=0.50).

Conclusion: A nurse navigator-led TOCC program is feasible and may be associated with decreased 30-day readmissions. The ongoing TOCC study will assess any association with LOS and patient satisfaction.

Abstract TP458: Stroke Disparities: Longer Lengths of Stay in Acute Stroke Patients With Medicaid

Introduction: Prolonged hospital stays expose stroke patients to hospital-acquired infections, increase overall cost of care, and delay the initiation of rehabilitation therapies. We sought to examine the factors associated with length of stay (LOS) in acute ischemic stroke (AIS) patients at a comprehensive stroke center (CSC) in an urban center. We hypothesized that patients being discharged to subacute rehabilitation (SAR) or nursing home facilities would have longer LOS.

Methods: Consecutive patients admitted to our stroke service from April to July 2018 with a principal diagnosis of AIS were included. Patients with transient ischemic attack, intracerebral hemorrhage or subarachnoid hemorrhage were excluded. Demographics, admission NIHSS, baseline modified Rankin Scale (mRS), discharge mRS, and discharge disposition were collected. LOS was calculated from date/time of patient registration to discharge.

Results: Baseline characteristics are shown in table 1. LOS and NIHSS were significantly correlated ( r s 0.745, p <0.001). Medicaid as primary insurance on admission was associated with longer LOS (21.9 days) as compared to Medicare (6.5 days) or commercial insurance (2.6 days) [p=0.017]. Higher discharge mRS was associated with longer LOS [p=0.002]. Discharge to SAR was associated with longer LOS (22.9 days) as compared to acute rehab (8.8 days), home with home health (3.2 days), or home (2.6 days) [p = 0.001]. There was no difference in LOS according to baseline mRS, age, gender, or race.

Conclusions: Higher admission NIHSS, Medicaid insurance on admission, discharge to SAR, and discharge mRs &gt4 were significantly associated with longer LOS in AIS patients. Systems of care interventions are needed to address disparity in LOS for Medicaid patients.

Place Cell-Like Activity in the Primary Sensorimotor and Premotor Cortex During Monkey Whole-Body Navigation

Primary motor (M1), primary somatosensory (S1) and dorsal premotor (PMd) cortical areas of rhesus monkeys previously have been associated only with sensorimotor control of limb movements. Here we show that a significant number of neurons in these areas also represent body position and orientation in space. Two rhesus monkeys (K and M) used a wheelchair controlled by a brain-machine interface (BMI) to navigate in a room. During this whole-body navigation, the discharge rates of M1, S1, and PMd neurons correlated with the two-dimensional (2D) room position and the direction of the wheelchair and the monkey head. This place cell-like activity was observed in both monkeys, with 44.6% and 33.3% of neurons encoding room position in monkeys K and M, respectively, and the overlapping populations of 41.0% and 16.0% neurons encoding head direction. These observations suggest that primary sensorimotor and premotor cortical areas in primates are likely involved in allocentrically representing body position in space during whole-body navigation, which is an unexpected finding given the classical hierarchical model of cortical processing that attributes functional specialization for spatial processing to the hippocampal formation.

Deficiency of tumor suppressor NDRG2 leads to attention deficit and hyperactive behavior

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent psychiatric disorder in children. Although an imbalance of excitatory and inhibitory inputs has been proposed as contributing to this disorder, the mechanisms underlying this highly heterogeneous disease remain largely unknown. Here, we show that N-myc downstream-regulated gene 2 (NDRG2) deficiency is involved in the development of ADHD in both mice and humans. Ndrg2-knockout (Ndrg2-/-) mice exhibited ADHD-like symptoms characterized by attention deficits, hyperactivity, impulsivity, and impaired memory. Furthermore, interstitial glutamate levels and excitatory transmission were markedly increased in the brains of Ndrg2-/- mice due to reduced astroglial glutamate clearance. We developed an NDRG2 peptide that rescued astroglial glutamate clearance and reduced excitatory glutamate transmission in NDRG2-deficient astrocytes. Additionally, NDRG2 peptide treatment rescued ADHD-like hyperactivity in the Ndrg2-/- mice, while routine methylphenidate treatment had no effect on hyperactivity in these animals. Finally, children who were heterozygous for rs1998848, a SNP in NDRG2, had a higher risk of ADHD than children who were homozygous for rs1998848. Our results indicate that NDRG2 deficiency leads to ADHD phenotypes and that impaired astroglial glutamate clearance, a mechanism distinct from the well-established dopamine deficit hypothesis for ADHD, underlies the resultant behavioral abnormalities.

Overexpression of NDRG2 Increases Iodine Uptake and Inhibits Thyroid Carcinoma Cell Growth In Situ and In Vivo

Medullary thyroid carcinoma (MTC) is an uncommon and highly aggressive tumor of the neuroendocrine system, which derives from the neuroendocrine C cells of the thyroid gland. Except for surgical resection, there are not very many effective systemic treatment options for MTC. N-Myc downstream-regulated gene 2 (NDRG2) had a significantly lower expression in MTC compared with normal thyroid tissue. However, the function of NDRG2 in MTC oncogenesis is largely unknown. In this study, we found that overexpression of NDRG2 inhibited the proliferation of TT cells (human medullary thyroid carcinoma cells) in vitro and suppressed the development of MTC in a nude mouse xenograft model. Further analysis revealed that NDRG2 arrested the cell cycle G₀/G₁ phase progression and induced TT cell apoptosis. Moreover, NDRG2 overexpression may mediate the antiproliferative effect by reducing cyclin D1 and cyclin E protein levels. We also found aberrant NDRG2-mitigated TT cell migration and invasion in vitro. Sodium/iodide symporter (NIS) mediates active I⁻ transport into the thyroid follicular cells, and radionuclide treatment is a promising therapy for MTC. Our current data revealed that NDRG2 overexpression enhanced NIS level in TT cells and increased their iodine uptake in vitro. Furthermore, ^99mTcO₄⁻ radionuclide imaging of the xenograft tumors indicated that NDRG2 could promote NIS-mediated radionuclide transport. In conclusion, the present study suggested that NDRG2 is a critical molecule in the regulation of MTC biological behavior and a potential promoter in radioactive iodine therapy.

N-myc downstream-regulated gene 2 in the nervous system: from expression pattern to function

Human N-myc downstream-regulated gene 2 (NDRG2) has been shown to be a multifunctional protein associated with cell proliferation, differentiation, transmembrane transport, and stress responses. In most mammalian brains, NDRG2 is principally expressed in astrocytic cells throughout different regions. NDRG2 has been increasingly implicated in the regulation of neurogenesis and in the development of nervous system diseases, including neurodegeneration, ischemia, and glioblastoma. This review summarizes the distribution and subcellular localization of NDRG2 in brain tissues, highlights the physiological actions of NDRG2 in the nervous system, and further discusses the roles of NDRG2 during the occurrence and development of several nervous system diseases.

Multi-component adsorption model for pellicle formation: The influence of salivary proteins and non-salivary phospho proteins on the binding of histatin 5 onto hydroxyapatite

The acquired enamel pellicle formed by selective adsorption of proteins in whole saliva is a protective integument on the tooth surface. The purpose of the present study was to investigate the formation of human acquired enamel pellicle using an in vitro hydroxyapatite (HA) model and 3H-histatin 5 to allow accurate measurement of histatin 5 binding in a multi-component experimental system. A binary system was employed by mixing 3H-histatin 5 with one unlabeled protein prior to incubation with HA or by first incubating 3H-histatin 5 with the HA which had been pre-coated with one of a panel of unlabeled proteins (human albumin, salivary amylase, lysozyme, acidic PIFs, statherin, the N-terminal fragment of statherin, and egg yolk phosvitin). A ternary system was employed by mixing 3H-histatin 5 with HA sequentially pre-coated with two different unlabeled proteins, including recombinant histatin 1. The results showed that only salivary statherin and egg yolk phosvitin promote histatin 5 adsorption significantly. The amount of histatin 5 adsorbed was also found to increase as a function of the amount of phosvitin and statherin used to pre-coat HA up to a maximum level that was two- to four-fold greater than that observed on untreated HA. These data suggest that specific protein-protein interactions may play important roles in pellicle formation in vivo.

Ultra-high redox enzyme signal transduction using highly ordered carbon nanotube array electrodes

We report on a highly ordered array of carbon nanotubes (CNTs) that serves as a universally direct nanoelectrode interface for redox proteins and provides an efficient conduit for electron transfer. The site-selective, covalent docking of the enzyme glucose oxidase (GO(x)) on the CNT tips is found to have a marked effect on enhancing electron transfer properties, as measured by cyclic voltammetry. A unimolecular electron transfer rate of 1500 s(-1) has been measured for this system, a value exceeding the rate of oxygen reduction by glucose oxidase. Furthermore, the redox enzyme-CNT array conjugate can be utilized as a quantitative, substrate-specific biosensor.

Optical properties of waveguides written by a 26 MHz stretched cavity Ti:sapphire femtosecond oscillator

We report on the fabrication, by a 26 MHz stretched-cavity femtosecond Ti:sapphire oscillator, of optical waveguides in different glass substrates, and their optical characterization. Operation of these waveguides in the telecom range at 1.55 microm is demonstrated. Digital holography microscopy is used to measure their refractive index profile. The results evidence a strong dependence of the fabrication process on the glass matrix.

Electronic transport in a controllably grown carbon nanotube-silicon heterojunction array

A uniform array of a new type of heterojunction formed between carbon nanotubes and silicon is studied. The heterojunction array was controllably grown with parallel and uniform nanotubes vertically aligned to the silicon substrate using a self-organized nanopore array template. The pronounced rectifying characteristics of the heterojunction were measured with an on/off ratio as high as 10(5) at 4 V. The analysis shows a large and type-I band offset at the heterojunction. The charge transport in the nanotubes is found to be strongly coupled to and limited by the dielectric charging and polarization in the hosting alumina matrix surrounding the nanotubes.

Physical parameters of hydroxyapatite adsorption and effect on candidacidal activity of histatins

Histatins 1, 3 and 5 are the major members of a histidine-rich protein family present in human salivary secretions. These proteins are distinct from many salivary proteins in their high positive charge density at neutral pH, and their antibacterial and antifungal properties. In this study, the hydroxyapatite adsorption characteristics of histatin 1, containing a single phosphoserine residue, recombinantly expressed histatin 1, native histatin 3, synthetic histatin 5 and an internal 12-residue sequence of histatin 5 were investigated. A Langmuir-type model was used to analyse the adsorption. A comparison of the affinities and binding sites of phosphorylated and recombinant histatin 1 provided an estimate of the positive influence of the single phosphoseryl group on mineral adsorption. Furthermore, an apparent correlation was shown to exist between peptide chain length and the number of binding sites. The influence of histatin 5 adsorption on its anticandidal activity was also investigated by performing Candida albicans killing assays with histatin 5 and histatin 5/hydroxyapatite suspensions. A decrease in killing activity was observed with the increase of hydroxyapatite present. The results suggest that the anticandidal properties of histatin 5 could be impaired by the conformations resulting from mineral adsorption, or that putative cellular receptors necessary for candidacidal activity are inaccessible when histatin 5 is adsorbed on hydroxyapatite.

Stroke disease management--a framework for comprehensive stroke care

Disease management is an approach to patient care that coordinates medical resources for the patient across the entire healthcare delivery system throughout the lifetime of the patient with the disease. Stroke is suitable for disease management as it is a well-known disease with a high prevalence, high cost, variable practice pattern, poor clinical outcome, and managed by a non-integrated healthcare system. It has measurable and actionable outcomes, with available local expertise and support of the Ministry of Health. Developing the programme requires a multidisciplinary team, baseline data on target populations and healthcare services, identification of core components, collaboration with key stakeholders, development of evidence-based clinical practice guidelines and carepaths, institution of care coordinators, use of information technology and continuous quality improvement to produce an effective plan. Core components include public education, risk factor screening and management, primary care and specialist clinics, acute stroke units, inpatient and outpatient rehabilitation facilities, and supportive community services including medical, nursing, therapy, home help and support groups for patients and carers. The family physician plays a key role. Coordination of services is best done by a network of hospital and community-based care managers, and is enhanced by a coordinating call centre. Continuous quality improvement is required, with audit of processes and outcomes, facilitated by a disease registry. Pitfalls include inappropriate exclusion of deserving patients, misuse, loss of physician and patient independence, over-estimation of benefits, and care fragmentation. Collaboration and cooperative among all parties will help ensure a successful and sustainable programme.

Hospital costs for stroke care in Singapore

We performed this prospective study to determine the cost of care for acute stroke patients admitted to hospital. Stroke was subtyped into subarachnoid hemorrhage (SAH), intraparenchymal hemorrhage (IPH), nonlacunar infarct (NLC), lacunar infarct (LAC) and transient ischemic attack (TIA). Cost of care was computed for the various services the patient received. At the time of the study, US$ 1 = S$1. 50. 426 patients were studied. Mean length of stay (LOS) was 17 days. Mean cost/discharge was S$7,547. Ward charges accounted for 38.2%, radiology 14.5%, doctors' fees 10.3%, drugs 8.4%, therapy 7.3%. Cost was highly correlated with LOS, r(2) = 0.73. Mean cost/discharge was SAH S$28,539, IPH S$14,398, NLC S$7,476, LAC S$3,517, TIA S$1,962. Initial hospitalization cost for stroke is highly correlated with LOS. The bulk of cost is attributable to ward stay. Cost/discharge is highest with SAH, and in descending order IPH, NLC, LAC, TIA.

Role of ischemia in rats with spinal cord injury induced by decompression sickness

The microsphere technique was used to determine whether blood flow to the central nervous system and various organs is impaired in rats with spinal cord injury induced by decompression sickness. For this purpose cannulas were placed in the left ventricle of the rats for the injection of microspheres and in the tail artery as the reference site for withdrawal of blood for the calculation of cardiac output (CO) and blood flow (BF) and for measurement of blood pressure (BP) and heart rate (HR). The rats were then subjected to a simulated dive that by electrophysiologic criteria rapidly (within 60 min after diving) induces severe neurologic deficits in the cord. Microspheres were used to determine CO and BF before and at 10, 60, and 180 min after diving. CO, BP, and HR were not affected by diving. BF to various regions of the brain, heart, bone, and fat was also not affected by diving. BF decreased in the lung (40%) and skeletal muscle (50%) and increased in spinal cord (20%) at 10 min after diving. At 60 and 180 min after diving the only alterations seen were increases in hepatic arterial and portal BF. Analysis of the distribution of cardiac output showed that diving induced changes that essentially paralleled the BF changes described above. We conclude that perfusion in the central nervous system is maintained in rats with spinal cord injury induced by decompression sickness. These results indicate that ischemia does not play a role in the pathophysiology of neuronal injury in this model of decompression sickness.

Role of extravascular gas bubbles in spinal cord injury induced by decompression sickness in the rat

We have evaluated the contribution of extravascular gas bubbles to spinal cord injury in decompression sickness. For this purpose, a model of decompression sickness was developed by subjecting rats to simulated dives using compressed air. Various diving profiles were tested and the presence of spinal cord injury was demonstrated by electrophysiologic measurements. To evaluate the space occupying lesions induced by gas bubbles in the white matter, the spinal cord was fixed by perfusion with 10% buffered formalin. Tissue blocks from cervical, thoracic, and lumbar spinal cords were embedded in paraffin. Tissue sections were double stained with luxol fast blue and hematoxylin and eosin. The space occupying lesions were quantified with a digitizer tablet. The fractional area of the lesions was 0.009% in controls and 0.026% in rats subjected to diving. We conclude that the volume of extravascular free gas present in the cord of rats with spinal decompression sickness is small and that artifacts of tissue preparation contribute to the volume estimate. As far as can be judged from the results in this animal model, the contribution of extravascular gas bubbles to spinal cord decompression injury is minor.

Adenocarcinoma-reactive human monoclonal antibody MS2B6 defines an antigen in simple glandular epithelium

A human monoclonal antibody (MAb), MS2B6, produced from splenocytes isolated from a patient with advanced papillary serous cystadenocarcinoma of the ovary, defines a unique human tumor-associated antigen. This antigen, EA2B6 (epithelial antigen 2B6), is expressed in a tissue-restricted manner on cultured and fresh human adenocarcinomas and some normal glandular epithelial tissues. EA2B6 is a 38-48 kD protein antigen that co-fractionates with the nuclear matrix-intermediate filament scaffold of simple glandular epithelial tissues. EA2B6 is a molecule with restricted solubility, and in vitro antigen-antibody binding is dependent on the antigen being presented on a solid support. To determine if EA2B6 is a cytokeratin, competition studies were undertaken with several cytokeratin-specific murine monoclonal antibodies. None of these antibodies inhibited the binding of human MAb MS2B6 to partially purified EA2B6. Less than 1% of HT29 colon adenocarcinoma cells and fresh ovarian adenocarcinoma ascites cells express EA2B6 on their surface. The majority of EA2B6 is intracellular. Because of the restricted tissue distribution of this antigen and stability of the antibody, we believe MS2B6 is a good candidate for MAb-mediated diagnosis and therapy of human adenocarcinomas.

Raising Tibet

Thermochronologic, sedimentologic, oceanographic, and paleoclimatic studies suggest that rapid uplift and unroofing of southern Tibet began about 20 million years ago and that the present elevation of much of the Tibetan plateau was attained by about 8 million years ago. Hypotheses advanced to explain the tectonic evolution of the India-Asia collision, which began about 40 to 50 million years ago, predict the timing and rates of crustal thickening of the southern margin of Asia. However, these models do not predict the prominently enhanced early Miocene denudation and uplift that are manifested in a variety of geological records. A model involving continental extrusion, development of a crustal-scale thrust ramp of the Main Central Thrust beneath the Gangdese belt, and lithospheric delamination provides a history consistent with these observations.

Human monoclonal antibody recognizing an antigen associatedwith ovarian and other adenocarcinomas

MS2B6, a human monoclonal antibody derived from a patient with advanced ovarian cancer, has been used to study the distribution and characteristics of its target antigen. The MS2B6 antigen was detected by immunoperoxidase studies in 41 of 41 epithelial ovarian cancers and in the majority of nonovarian adenocarcinomas. Among normal tissues the MS2B6 antigen was found in the adult epithelia of the fallopian tube, endometrium, endocervix, colon, bronchus, breast, sweat duct, and large renal ducts. No detectable antigen was found in peritoneal epithelia, tissue stromal cells, spleen, thymus, or blood-borne cells. Immunoblotting analysis showed that the MS2B6 epitope resides on polypeptides of 38, 44, and 60 kd. The cellular location of the MS2B6 antigen was studied with immunoperoxidase and immunofluorescent staining and immunoelectronmicroscopy of ovarian cancer ascites tumor cells. The results suggest that in ascites tumor cells the MS2B6 antigen is located in a layer of the peripheral cytoplasm beginning just below the cell membrane. MS2B6 may be useful as an imaging or therapeutic agent.

The effects of metabolic acidosis and alkalosis on the response to sympathomimetic drugs in dogs

Sympathomimetic drugs are commonly used in many circumstances to increase cardiac output, blood pressure, and myocardial contractility. However, factors such as acidosis or alkalosis are known to influence the action of these drugs. This study looked at the response to the administration of epinephrine, norepinephrine, dopamine, dobutamine, isoproterenol, and glucagon at normal pH and under acidotic (pH 7.2 +/- 0.01) and alkalotic (pH 7.59 +/- 0.01) conditions in 17 dogs. Acidosis was produced with an infusion of hydrochloric acid and alkalosis by infusion of sodium bicarbonate. The infusions were given over one hour followed by a 15- to 30-minute stabilization period. With the administration of each sympathomimetic drug at each pH level, hemodynamic parameters and measurements of myocardia; contractility were recorded. Epinephrine increased cardiac output at normal pH, but decreased cardiac output under conditions of both acidosis and alkalosis; the net change from values at pH 7.40 was nearly 3 L/min. The only other drug to demonstrate this reversal of cardiac output, though to a lesser degree, was dopamine, 10 microg/kg/min, and only in the alkalotic state. Dobutamine was the only drug that decreased contractility under acidotic conditions, while all other drugs caused an increase. In sum, epinephrine was the only drug markedly affected by metabolic acidosis and alkalosis. Isoproterenol's hemodynamic effects were altered the least by changes in acid-base balance. Alkalosis had an equally adverse effect on the cardiovascular system as compared with acidosis.

Generation of human monoclonal antibodies to cancer-associated antigens using limited numbers of patient lymphocytes

A limiting dilution method for the efficient transformation by Epstein-Barr virus (EBV) of human B lymphocytes has been applied to the production of human monoclonal antibodies to ovarian cancer-associated antigens. Limited numbers (e.g., 2 X 10(5)) of EBV-infected B lymphocytes from ovarian cancer patient spleen, lymph node, tumor, ascites and blood were successfully transformed using this method. An immunofiltration assay system was employed to identify EBV transformants secreting IgM antibody which reacted selectively with ovarian cancer patient ascites tumor cells, but not with a mixture of normal cell types. A miniature Western blot assay was utilized to screen for IgG reactivity to protein species in detergent extracts of ovarian cancer tumor cells. EBV-transformed cells selected after screening were then fused with heteromyeloma fusion partner SHM-D33 resulting in efficient recovery of hybridomas secreting MAb of the desired specificity. Human MAbs which selectively react with antigens associated with ovarian cancer tumor cells were obtained.

Calculator assisted cardiorespiratory monitoring

The newest card-programmable calculators are more flexible and powerful enough to process a variety of complex data, derive appropriate variables, and print the titles of the values and the results. These capabilities make the information derived from aggressive cardiorespiratory monitoring more usable, and specifically, have increased the benefits from the use of pulmonary artery catheters and techniques such as phonocardiography. A program using 800 steps and 20 memory registers and an illustration of the value of both the monitoring and calculator in ICU care are presented.