Brain dynamics reflecting an intra-network brain state is associated with increased posttraumatic stress symptoms in the early aftermath of trauma

This study examines the association between brain dynamic functional network connectivity (dFNC) and current/future posttraumatic stress (PTS) symptom severity, and the impact of sex on this relationship. By analyzing 275 participants' dFNC data obtained ~2 weeks after trauma exposure, we noted that brain dynamics of an inter-network brain state link negatively with current (r=-0.179, pcorrected= 0.021) and future (r=-0.166, pcorrected= 0.029) PTS symptom severity. Also, dynamics of an intra-network brain state correlated with future symptom intensity (r = 0.192, pcorrected = 0.021). We additionally observed that the association between the network dynamics of the inter-network brain state with symptom severity is more pronounced in females (r=-0.244, pcorrected = 0.014). Our findings highlight a potential link between brain network dynamics in the aftermath of trauma with current and future PTSD outcomes, with a stronger protective effect of inter-network brain states against symptom severity in females, underscoring the importance of sex differences.

Interim Estimates of 2023-24 Seasonal Influenza Vaccine Effectiveness - United States

In the United States, annual influenza vaccination is recommended for all persons aged ≥6 months. Using data from four vaccine effectiveness (VE) networks during the 2023-24 influenza season, interim influenza VE was estimated among patients aged ≥6 months with acute respiratory illness-associated medical encounters using a test-negative case-control study design. Among children and adolescents aged 6 months-17 years, VE against influenza-associated outpatient visits ranged from 59% to 67% and against influenza-associated hospitalization ranged from 52% to 61%. Among adults aged ≥18 years, VE against influenza-associated outpatient visits ranged from 33% to 49% and against hospitalization from 41% to 44%. VE against influenza A ranged from 46% to 59% for children and adolescents and from 27% to 46% for adults across settings. VE against influenza B ranged from 64% to 89% for pediatric patients in outpatient settings and from 60% to 78% for all adults across settings. These findings demonstrate that the 2023-24 seasonal influenza vaccine is effective at reducing the risk for medically attended influenza virus infection. CDC recommends that all persons aged ≥6 months who have not yet been vaccinated this season get vaccinated while influenza circulates locally.

Expectations of radiographer reporting roles: A multimethod evaluation across a single imaging network

INTRODUCTION

Prior studies have demonstrated inconsistent development and utilisation of radiographers in the reporting of radiographs, and there is ongoing consideration of the level at which such radiographers should be educated to and operating at. This study aimed to explore and evaluate expectation and utilisation of radiographers currently, or training in, reporting in projection radiography across one integrated care system (ICS).

METHODS

A multi-method approach was utilised, with document analysis of projection radiography reporting role job descriptions and person specifications and an online survey of managers and clinical leads. A single ICS in the north of England formed the setting for the study.

RESULTS

This study demonstrated variation in implementation and utilisation of the role across trusts within the ICS. Inconsistencies in scope, expected underpinning education and role activity were identified. Radiographers autonomously reporting in projection radiography were titled advanced practitioners, however are not expected to achieve national educational standards for such roles and are not empowered to work at this level of practice by their employers. It was acknowledged that staffing pressures hinder appropriate role utilisation and reporting capacity.

CONCLUSION

Inconsistent development and utilisation of radiographers in such roles may hamper collaboration and service delivery across a network. Identifying variation and working towards role standardisation could promote cross-organisational working and improve career progression opportunities.

IMPLICATIONS FOR PRACTICE

Scoping the reporting radiographer workforce may assist and guide future imaging service and workforce planning.

Cepheid Xpert Xpress Flu/RSV evaluation performed by minimally trained non-laboratory operators in a CLIA-waived environment

The COVID-19 pandemic highlighted the significance of readily available and easily performed viral testing for surveillance during future infectious pandemics. The objectives of this study were: to assess the performance of the Xpert Xpress Flu and/or RSV test, a multiplex PCR assay for detecting influenza A and B virus and respiratory syncytial virus nucleic acids in respiratory tract specimens, relative to the Quidel Lyra Influenza A+B assay and the Prodesse ProFlu+ assay, and the system's ease of use by minimally trained operators. Overall, the Xpert Xpress Flu/RSV test demonstrated a high positive and negative percent agreement with the comparator assays, and was easy to use and interpret results, based on the operators’ feedback. We concluded that the Xpert Xpress Flu/RSV test is sensitive, specific, and easy to use for the diagnosis of influenza and RSV by minimally trained operators and can be a valuable tool in future infectious clusters or pandemics.

Risk factors and medical resource utilization in US adults hospitalized with influenza or respiratory syncytial virus in the Hospitalized Acute Respiratory Tract Infection study

Background

Influenza and respiratory syncytial virus (RSV) are associated with substantial morbidity and mortality in the United States. We assessed risk factors for severe disease and medical resource utilization (MRU) among US adults hospitalized with influenza or RSV in the Hospitalized Acute Respiratory Tract Infection (HARTI) study.

Methods

HARTI was a prospective global (40 centers, 12 countries) epidemiological study of adults hospitalized with acute respiratory tract infections conducted across the 2017–2019 epidemic seasons. Patients with confirmed influenza or RSV were followed up to 3 months post‐discharge. Baseline characteristics, prevalence of core risk factors (CRFs) for severe disease (age ≥65 years, chronic heart or renal disease, chronic obstructive pulmonary disease, or asthma), and MRU were summarized descriptively.

Results

The US cohort included 280 influenza‐positive and 120 RSV‐positive patients. RSV patients were older (mean: 63.1 vs. 59.7 years) and a higher proportion had CRFs (87.5% vs. 81.4%). Among those with CRFs (influenza, n = 153; RSV, n = 99), RSV patients required longer hospitalizations (median length of stay: 4.5 days) and a greater proportion (79.8%) required oxygen supplementation during hospitalization compared with influenza patients (4.0 days and 59.5%, respectively). At 3 months post‐discharge, a greater proportion of RSV patients with CRFs reported use of antibiotics, antitussives, bronchodilators, and inhaled and systemic steroids versus those with influenza and CRFs. Many patients with CRFs reported hospital readmission at 3 months post‐discharge (RSV: 13.4%; influenza: 11.9%).

Conclusions

MRU during and post‐hospitalization due to RSV in adults is similar to or greater than that of influenza. Enhanced RSV surveillance and preventive and therapeutic interventions are needed.

Risk Factors and Medical Resource Utilization of Respiratory Syncytial Virus, Human Metapneumovirus and Influenza Related Hospitalizations in Adults – A Global Study During the 2017-2019 Epidemic Seasons (Hospitalized Acute Respiratory Tract Infection [HARTI] Study)

Background

Respiratory syncytial virus (RSV), human metapneumovirus (hMPV), and influenza are respiratory pathogens leading to hospitalization in adults. Our understanding of the disease burden is limited to data from single-center or 1-season studies in elderly patients. The HARTI study allows comparison of risk factors for progression to severe disease and medical resources utilization (MRU) during and post-hospitalization in adults diagnosed with influenza, RSV, or hMPV.

Methods

This was a prospective global study in adults hospitalized with acute respiratory tract infection (40 centers, 12 countries). Participants with influenza, RSV, or hMPV were enrolled in a substudy and followed for up to 3 months postdischarge.

Results

Overall, 366 influenza, 238 RSV, and 100 hMPV-infected participants enrolled in the substudy. RSV participants were older and had greater frequency of risk factors and longer duration of symptoms before hospitalization than influenza participants. The RSV and hMPV groups received more bronchodilators, corticosteroids, and oxygen supplementation. No significant differences in intensive care unit admissions or complications were observed. Readmission occurred in 20%–33% of patients within 3 months postdischarge, with the highest rates for RSV and hMPV. In-hospital death occurred in 2.5% of RSV, 1.6% of influenza, and 2% of hMPV participants. In multivariate analyses, length of stay was independently associated with country, renal disease, and increased age; probability of receiving supplemental oxygen was associated with pathogen (hMPV > RSV > influenza), abnormal chest x-ray, and increased age.

Conclusions

Although influenza is more frequent, the HARTI study demonstrates greater frequency of underlying risk factors and MRU for RSV and hMPV vs influenza in hospitalized adults, indicating a need for effective interventions.

Clinical prediction rule for SARS-CoV-2 infection from 116 U.S. emergency departments 2-22-2021

Objectives

Accurate and reliable criteria to rapidly estimate the probability of infection with the novel coronavirus-2 that causes the severe acute respiratory syndrome (SARS-CoV-2) and associated disease (COVID-19) remain an urgent unmet need, especially in emergency care. The objective was to derive and validate a clinical prediction score for SARS-CoV-2 infection that uses simple criteria widely available at the point of care.

Methods

Data came from the registry data from the national REgistry of suspected COVID-19 in EmeRgency care (RECOVER network) comprising 116 hospitals from 25 states in the US. Clinical variables and 30-day outcomes were abstracted from medical records of 19,850 emergency department (ED) patients tested for SARS-CoV-2. The criterion standard for diagnosis of SARS-CoV-2 required a positive molecular test from a swabbed sample or positive antibody testing within 30 days. The prediction score was derived from a 50% random sample (n = 9,925) using unadjusted analysis of 107 candidate variables as a screening step, followed by stepwise forward logistic regression on 72 variables.

Results

Multivariable regression yielded a 13-variable score, which was simplified to a 13-point score: +1 point each for age>50 years, measured temperature>37.5°C, oxygen saturation<95%, Black race, Hispanic or Latino ethnicity, household contact with known or suspected COVID-19, patient reported history of dry cough, anosmia/dysgeusia, myalgias or fever; and -1 point each for White race, no direct contact with infected person, or smoking. In the validation sample (n = 9,975), the probability from logistic regression score produced an area under the receiver operating characteristic curve of 0.80 (95% CI: 0.79–0.81), and this level of accuracy was retained across patients enrolled from the early spring to summer of 2020. In the simplified score, a score of zero produced a sensitivity of 95.6% (94.8–96.3%), specificity of 20.0% (19.0–21.0%), negative likelihood ratio of 0.22 (0.19–0.26). Increasing points on the simplified score predicted higher probability of infection (e.g., >75% probability with +5 or more points).

Conclusion

Criteria that are available at the point of care can accurately predict the probability of SARS-CoV-2 infection. These criteria could assist with decisions about isolation and testing at high throughput checkpoints.

Blood Biomarkers for Detection of Brain Injury in COVID-19 Patients

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus attacks multiple organs of coronavirus disease 2019 (COVID-19) patients, including the brain. There are worldwide descriptions of neurological deficits in COVID-19 patients. Central nervous system (CNS) symptoms can be present early in the course of the disease. As many as 55% of hospitalized COVID-19 patients have been reported to have neurological disturbances three months after infection by SARS-CoV-2. The mutability of the SARS-COV-2 virus and its potential to directly affect the CNS highlight the urgency of developing technology to diagnose, manage, and treat brain injury in COVID-19 patients. The pathobiology of CNS infection by SARS-CoV-2 and the associated neurological sequelae of this infection remain poorly understood. In this review, we outline the rationale for the use of blood biomarkers (BBs) for diagnosis of brain injury in COVID-19 patients, the research needed to incorporate their use into clinical practice, and the improvements in patient management and outcomes that can result. BBs of brain injury could potentially provide tools for detection of brain injury in COVID-19 patients. Elevations of BBs have been reported in cerebrospinal fluid (CSF) and blood of COVID-19 patients. BB proteins have been analyzed in CSF to detect CNS involvement in patients with infectious diseases, including human immunodeficiency virus and tuberculous meningitis. BBs are approved by the U.S. Food and Drug Administration for diagnosis of mild versus moderate traumatic brain injury and have identified brain injury after stroke, cardiac arrest, hypoxia, and epilepsy. BBs, integrated with other diagnostic tools, could enhance understanding of viral mechanisms of brain injury, predict severity of neurological deficits, guide triage of patients and assignment to appropriate medical pathways, and assess efficacy of therapeutic interventions in COVID-19 patients.

Absence of QT prolongation after administration of a 24-mg bimodal-release ondansetron pill (RHB-102)

OBJECTIVES

Prospective data evaluating the effect of ondansetron on the corrected QT (QTc) interval is lacking in emergency department clinical use. As part of a randomized trial of a 24-mg bimodal-release ondansetron (RHB-102) pill, we tested the effect of RHB-102 compared to placebo on QTc change.

METHODS

This was a planned safety outcome analysis within a multicenter, double-blind, placebo-controlled trial. The trial compared the effects of RHB-102 among patients ≥12 years who presented to 21 centers with symptoms of acute gastroenteritis. Patients with an initial baseline electrocardiogram as well as a follow-up electrocardiogram 4 h later were included in the analysis. The safety endpoint for this analysis was the change from baseline in QTc interval at 4 h, the median time at which ondansetron serum level peaks.

RESULTS

A total of 147 patients were included with a mean baseline QTc in the RHB-102 and placebo arms of 410 and 406 ms, respectively. There was no difference in the change in QTc at 4 h post-study drug administration between the RHB-102 (+4, 95% CI 1-8 ms) and placebo group (+5, 95% CI 1-9 ms). In the RHB-102 arm, 6.6% of patients had a QTc change >30 ms and in the placebo arm 3.6% (p = 0.48). No patient in either arm had a QTc change >60 ms after study drug administration.

CONCLUSION

In patients with normal baseline QTc, 24-mg bimodal-release ondansetron did not prolong the QTc in comparison to placebo.

The AURORA Study: a longitudinal, multimodal library of brain biology and function after traumatic stress exposure

Adverse posttraumatic neuropsychiatric sequelae (APNS) are common among civilian trauma survivors and military veterans. These APNS, as traditionally classified, include posttraumatic stress, postconcussion syndrome, depression, and regional or widespread pain. Traditional classifications have come to hamper scientific progress because they artificially fragment APNS into siloed, syndromic diagnoses unmoored to discrete components of brain functioning and studied in isolation. These limitations in classification and ontology slow the discovery of pathophysiologic mechanisms, biobehavioral markers, risk prediction tools, and preventive/treatment interventions. Progress in overcoming these limitations has been challenging because such progress would require studies that both evaluate a broad spectrum of posttraumatic sequelae (to overcome fragmentation) and also perform in-depth biobehavioral evaluation (to index sequelae to domains of brain function). This article summarizes the methods of the Advancing Understanding of RecOvery afteR traumA (AURORA) Study. AURORA conducts a large-scale (n = 5000 target sample) in-depth assessment of APNS development using a state-of-the-art battery of self-report, neurocognitive, physiologic, digital phenotyping, psychophysical, neuroimaging, and genomic assessments, beginning in the early aftermath of trauma and continuing for 1 year. The goals of AURORA are to achieve improved phenotypes, prediction tools, and understanding of molecular mechanisms to inform the future development and testing of preventive and treatment interventions.

2020. Concordance of Direct vs. Indirect Pathogen Detection Using the BioFire® System

Background

Polymerase chain reaction (PCR) is a highly sensitive and specific method for pathogen detection. While direct methods enable rapid identification, they are limited by pathogen titer, available assays, or sample matrix. Transcriptomic analysis addresses these limitations by measuring systemic host gene expression changes to infections. The BioFire System uses sample-to-answer multiplex PCR that was adapted to detect 42 transcripts differentially expressed during viral and bacterial infections. Here we report concordance between indirect detection of viral respiratory pathogens and the FDA-cleared BioFire^® Respiratory Panel 2 (RP2).

Methods

Paired nasal pharyngeal swabs and blood samples were obtained by informed consent from patients with suspected acute respiratory illness. Swabs (COPAN FLOQSwab^™) were collected and stored in viral transport media (BD) for BioFire RP2 testing and peripheral blood samples were collected in PAXgene tubes (Qiagen) for testing with the research use only human response (HR) panel. A logistic regression model was developed to classify viral and nonviral positive samples using normalized quantification cycles for each assay. Probabilities of viral infection for each sample were calculated via cross-validation and an optimal threshold of positivity was identified.

Results

Overall accuracy of the HR panel relative to BioFire RP2 was 86% (CI_95% 80%, 91%) for all viral infections with an area under the receiver operating characteristic curve of 0.87 (CI_95% 0.76, 0.95). Accuracy varied by infection etiology: Influenza virus 100% (CI_95% 88%, 100%) Human Rhinovirus/Enterovirus 63% (CI_95% 35%, 85%), other viral infections 50% (CI_95% 25%, 75%). While most of the BioFire RP2 negative results exhibited low viral probabilities, strong viral probabilities were measured in a few samples; this may be indicative of an infection at a low titer or the presence of a viral pathogen not on the BioFire RP2 Panel.

Conclusion

These results demonstrate that indirect transcriptomic analysis resulted in similar accuracy to direct viral pathogen detection in acute respiratory patients; however, additional research is needed to elucidate the relationship between transcriptional results and infectious etiologies.

Disclosures

C. Gritzen, BioFire Diagnostics, LLC.: Employee, Salary. T. Wilson, BioFire Diagnostics, LLC.: Employee, Salary. J. Nawrocki, BioFire Diagnostics, LLC.: Employee, Salary. M. Deneris, BioFire Diagnostics, LLC.: Employee, Salary. C. Baird, BioFire Diagnostics, LLC.: Employee, Salary. E. Ott, BioFire Diagnostics, LLC.: Employee, Salary. J. Jones, BioFire Diagnostics, LLC.: Employee, Salary. J. Bastar, BioFire Diagnostics, LLC.: Employee, Salary. H. Kim, BioFire Diagnostics, LLC.: Employee, Salary. S. House, Washington University School of Medicine: Research Contractor, Research support. D. Cohen, Nationwide Children’s Hospital: Research Contractor, Research support. A. Leber, Nationwide Children’s Hospital: Research Contractor, Research support. R. Crisp, BioFire Diagnostics, LLC.: Employee, Salary. A. Hemmert, BioFire Diagnostics, LLC.: Employee and Investigator, Salary.

Abstract 101: Endothelial-Specific Fibroblast Growth Factor Receptor 1 and 2 Deletion Impairs Vascular Remodeling and Recovery in an In Vivo Closed-Chest Model of Cardiac Ischemia-Reperfusion Injury

Introduction: Fibroblast growth factor (FGF) signaling is cardioprotective in various models of myocardial infarction. FGF receptors (FGFRs) are expressed in multiple cell types in the adult heart, but the cell type-specific FGFR signaling which mediates different cardioprotective endpoints is currently unknown.

Hypothesis: We hypothesize that endothelial FGFR signaling is essential for vascular remodeling after cardiac ischemia-reperfusion (IR) injury.

Methods: We have generated mice with a conditional ablation of the Fgfr1 and Fgfr2 genes in endothelial cells ( Tie2-Cre, Fgfr1 f/f , Fgfr2 f/f ). These mice and littermate controls were subjected to a clinically relevant, in vivo , closed-chest model of cardiac IR injury which includes 90 minutes of occlusion of the left anterior descending artery followed by reperfusion for 7 days. Echocardiography was performed at baseline, day 1, and day 7 of reperfusion, and histological staining was performed on day 7.

Results: Tie2-Cre, Fgfr1 f/f , Fgfr2 f/f mice had no baseline abnormalities in cardiac morphometry or function. When subjected to closed-chest, regional cardiac IR injury, Tie2-Cre, Fgfr1 f/f , Fgfr2 f/f mice showed significantly increased infarct size compared to controls at 7 days (37±3% vs. 15±5%, p<0.05) but not 1 day after reperfusion. Tie2-Cre, Fgfr1 f/f , Fgfr2 f/f mice also showed significantly worsened cardiac function (ejection fraction, stroke volume, and fractional shortening) compared to controls at 7 days (p<0.05) but not 1 day after reperfusion. Myocyte cross-sectional area measurement showed no impairment in the cardiac hypertrophic response in the Tie2-Cre, Fgfr1 f/f , Fgfr2 f/f mice. Tie2-Cre, Fgfr1 f/f , Fgfr2 f/f mice have normal vessel density in the non-injured state, but after cardiac IR injury, Tie2-Cre, Fgfr1 f/f , Fgfr2 f/f hearts showed significantly decreased vessel density (both capillaries and smooth muscle actin containing vessels, p<0.05) compared to controls in the peri-infarct area.

Conclusions: Ablation of FGFR1 and FGFR2 in endothelial cells results in impaired vascular remodeling, worsened cardiac functional recovery, and increased infarct size without affecting the cardiac hypertrophic response in an in vivo , closed-chest model of cardiac IR injury.

Stages in reproduction particularly vulnerable to xenobiotic hazards and nutritional deficits

Biochemical research has identified many failures in reproductive processes with specific nutrient deficits, xenobiotics and some infectious illnesses. This has led to some effective safeguards. During meiosis and fertilization, as genetic material divides and rearranges, it is exposed and open to mutation. A nutritionally unfavourable environment is a major risk factor. At stages of rapid cell division, differentiation and organisation, as in the embryo and later in the fetal brain, the child's survival, completeness and future health and ability are at stake. From months before conception, reproduction needs preparing for, especially with today's environmental pollution, even entering the foodchain. Care from before conception can contribute not only to the child's healthy basis for life, full development of brain, eyesight and other complex attributes, but also to the health of at least the subsequent generation. Since the female baby's oocytes are being formed while she is still in the womb, the grandmother's nutritional status, around the time of conceiving a daughter, can permanently affect a grandchild. Recent insights into evolution, particularly of the brain, give us fresh indications of dietary needs to fulfil human potential for health and acuity. Despite the hazards, nature is remarkably successful. This paper is not designed to alarm but to help attainment of full genetic potential. With healthy parents serious malformations are a low percentage. The numbers of babies with avoidable disorders, however, calls urgently for action, especially in our own inner cities and in developing countries where there is inadequate nutrition. Action will more than justify itself, including financially. It will reward handsomely.

Expression of G1 cyclins and cyclin-dependent kinase-2 activity during terminal differentiation of cultured human trophoblast

Cyclin-dependent kinases (Cdks) and their cyclin partners regulate mammalian cell proliferation and withdrawal from the cell cycle and, as such, control differentiation in many tissues. Studies were undertaken to examine the roles of cell cycle proteins in differentiating cytotrophoblasts. Cyclin E gene and protein expression was down-regulated after 24 h in cultured trophoblasts. Cdk2-associated kinase activity was decreased after 96 h in culture as was the amount of cyclin E in complexes with Cdk2; however, levels of the Cdk inhibitor, p27Kip1, were significantly increased. In freshly isolated trophoblasts and in 24-h cultures, the retinoblastoma gene product (pRb) was found in both the active and inactive forms, yet only hypophosphorylated, active pRb was present in syncytiotrophoblast. Thus, inactivation of Cdk2 through cyclin E down-regulation and increased p27Kip1 expression leads to an accumulation of active pRb in syncytiotrophoblast. Prevention of entry into S phase by hypophosphorylated pRb may allow trophoblasts to respond to signals that potentiate differentiation. Our studies suggest that regulation of G1-phase Cdk activity may be involved in the terminal differentiation process of cytotrophoblasts.

An investigation of indoor air contamination in residences above dry cleaners

An investigation of residences located above dry cleaning facilities was conducted to determine whether indoor and outdoor air concentrations of the dry cleaning solvent tetrachloroethene (perchloroethylene, PCE) were elevated compared to residences not near a dry cleaning facility. Data were also collected on the dry cleaners' operating conditions and equipment. Significantly elevated levels of PCE were found in the indoor air of each of six apartments located above dry cleaners compared to control residences for both day and night samples. The PCE concentrations in outdoor air near the dry cleaners were also significantly elevated compared to control locations and were lower than the concentrations measured indoors. The type of dry cleaning machine was significantly associated with the concentration of PCE found in the apartment above. A strong correlation was also found between the day and night PCE levels in the study apartments.

An immunochemical analysis of oxytocin and vasopressin prohormone processing in vivo

Antisera against partially processed, unamidated forms of AVP and OT were raised and characterized by radioimmunoassay and immunocytochemistry. These antibodies, and antibodies that recognize fully processed, amidated forms of AVP and OT, were used together with various fractionation methods to study the content of prohormones, partially processed and fully processed forms of AVP and OT in the hypothalamo-neurohypophysial system of adult and fetal (E21) rats. The levels of cleaved AVP and OT in the fetus were lower than those of the adult (1 to 3 orders of magnitude for brain and pituitary, respectively), and the detection of cleaved OT in brain and pituitary was delayed compared to that of AVP. Pro-AVP cleavage efficiency in the adult and the fetus was high (99 and 95% cleavage, respectively) resulting in formation of fully processed amidated forms of AVP, with no detectable partially processed peptides. Pro-OT processing in the adult was very similar (over 99% cleavage) resulting in formation of fully processed amidated OT. However, Pro-OT processing efficiency in the fetus was very low and incomplete, resulting in 40% unprocessed precursor and the accumulation of C-terminally extended unamidated intermediate forms (OT-Gly, OT-Gly-Lys, and OT-Gly-Lys-Arg).

Biochemical and immunocytochemical characterization and distribution of phosphorylated and nonphosphorylated subunits of neurofilaments in squid giant axon and stellate ganglion

Monoclonal antibodies to squid neurofilament (aNFP) and intermediate filament (aIFA) proteins were used as probes for the biochemical and immunocytochemical analyses of neurofilament structure and distribution in the squid giant axon and stellate ganglion. On Western blots the aNFP antibody stained exclusively the 220 kDa and high-molecular-weight (HMW) components of neurofilaments in the giant axon, whereas the aIFA antibody primarily labeled the 60 kDa protein in the giant axon and the 60 and 65 kDa proteins in the stellate ganglion. Dephosphorylation of axoplasmic proteins by alkaline phosphatase resulted in a decrease in the molecular weights of both the 220 kDa and HMW neurofilament proteins and a concomitant loss of reactivity with the aNFP antibody on Western blots. This indicated that the aNFP antibody is specific for a phosphorylated epitope in the neurofilament. Increased dephosphorylation of the 220 kDa protein led to an enhanced immunostaining of the resultant 190 kDa polypeptide by the aIFA antibody, suggesting that the phosphorylated epitope may mask the conserved epitope recognized by aIFA. Light and electron microscopic immunocytochemical studies show intense labeling by the aNFP antibody in the giant axon. In contrast, the aIFA antibody labeled the glial cells around the giant axon intensely, while labeling of the giant axon itself was considerably less than that with the aNFP antibody. Since the 60 kDa protein in axoplasm is intensely stained by the aIFA antibody on Western blots, the relatively low amounts of labeling seen on semithin and thin sections of the giant axon by this antibody may be due to the masking of the 60 kDa protein by in situ fixed axoplasmic proteins. However, the aIFA antibody intensely labeled glial cells within the stellate ganglion and "islands" of filaments and nuclear membranes within ganglion cells. No reactivity for either antibody was seen in synapses. The aNFP antibody specifically labeled "beadlike" portions and cross-bridges on the axonal neurofilaments, suggesting that these components consist of the 220 kDa and HMW proteins. In contrast, the aIFA antibody labeled relatively smooth filaments in ganglion and glial cells. These data suggest that the 65 kDa protein represents the squid glial filament protein and that the 60 kDa protein found in axoplasm represents the low-molecular-weight subunit in the axonal neurofilament. The latter appears to be formed and/or organized in "islands" of filaments within ganglion cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Measurement of human serum immunoreactive gamma-glutamyl transpeptidase in patients with malignant tumors using enzyme-linked immunosorbent assay

An enzyme-linked immunosorbent assay for human immunoreactive gamma-glutamyl transpeptidase (gamma-GTP) was developed. This assay was found to be simple, reproducible, and sensitive to 10 ng of the enzyme. Serum immunoreactive gamma-GTP content was significantly elevated in patients with various malignant tumors including liver cell cancer, lung cancer, gastric cancer, esophageal cancer, and colorectal cancer. On the other hand, in sera of patients with nonneoplastic diseases, the immunoreactive gamma-GTP content was not significantly elevated. No correlation was found between the serum levels of gamma-GTP determined by enzymatic assay and enzyme-linked immunosorbent assay, which indicates that, due to the presence of endogenous inhibitors and/or activators in sera, the enzyme activity may not reflect the true amount of enzyme protein. The measurement of immunoreactive gamma-GTP protein in sera appears to be useful for the detection and monitoring of certain malignant tumors.

A monoclonal antibody against gamma-glutamyltransferase from human primary hepatoma: its use in enzyme-linked immunosorbent assay of sera of cancer patients

A monoclonal antibody, gamma-120, was raised against a highly purified gamma-glutamyltransferase (gamma GT) from human primary hepatoma. The antibody preferentially bound to the small subunit of gamma GT from human hepatoma and kidney as evidenced by immunoblot analysis. Weak binding to the normal liver enzyme could be detected by solid-phase enzyme-linked immunosorbent assay (ELISA). With the use of this antibody, an ELISA was developed for the quantitation of immunoreactive gamma GT in human serum. Sera of 188 normal control subjects displayed a low level (9.4 micrograms/ml) of immunoreactive gamma GT. Highly elevated levels of immunoreactive gamma GT were detected in the sera of patients with primary hepatoma, metastatic liver cancer, pancreatic cancer, and certain types of lung cancer. Slightly elevated levels of immunoreactive gamma GT were seen in the sera of patients with liver cirrhosis. The levels of gamma GT were within a normal range in the sera of patients with gastrointestinal cancers and patients with nonmalignant diseases such as hepatitis and gallstones. The antibody has been shown to be useful for the diagnosis of some of the neoplastic diseases.

Establishment of an inbred line of mice that express a synergistic immune defect precluding in vitro responses to type 1 and type 2 antigens, B cell mitogens, and a number of T cell-derived helper factors

Introduction of the CBA/N X-linked gene into C3H mice has resulted in the establishment of a new strain of mice that has profound immunologic defects. B cells from these mice show significantly impaired in vitro immune responses to the T cell-independent type 1 antigen trinitrophenyl-Brucella abortus (TNP-BA) as well as markedly reduced proliferative responses to a number of B cell mitogens when compared with the responses of the parental control mice. The in vivo response of such mice to TNP-BA is, however, comparable to that of CBA/N mice. Furthermore, B cells from C3.CBA/N mice are unresponsive to the plaque-forming cell enhancing effects induced by EL4-derived supernatant in the presence of TNP-BA, unlike B cells obtained from CBA/N or C3H/Hen mice whose responsiveness to TNP-BA can be significantly enhanced in the presence of EL4-derived supernatant. The model we have presented to best explain these results suggests that B cells from C3.CBA/N mice can be stimulated only under conditions in which they can interact with carrier-specific T cell help and not under conditions where factor-dependent responses are dominant.

Defective regulation of B lymphocyte colony formation in patients with systemic lupus erythematosus

We have succeeded in generating B cell colonies from freshly separated human peripheral blood by the double agar layer technique and expanding them in liquid culture for several weeks. Populations of cells enriched in B cells were placed into the upper layer with or without bacterial LPS. Although B cell colonies were observed without LPS, the addition of LPS to the cells in the upper agar layer increased the number of colonies. Also necessary for optimal B cell colony formation was the presence in the lower agar layer of either culture supernatant of PHA-stimulated mononuclear cells or purified T cells and PHA. Without such helper factors in the lower layer, only a few B cell colonies were observed in the upper layer. By using these techniques, peripheral blood lymphocytes from normal individuals and patients with active systemic lupus erythematosus (SLE) were studied for the generation of B cell colonies. Significantly more B cell colonies were observed in patients with SLE, using either kind of "helper" factor. In addition, T cells from normal individuals and patients were tested for their ability to help B cell colony formation. The SLE T cells were found to be defective in this function relative to normal T cells. Thus, although patients with SLE were hyperactive in forming B cell colonies, thier T cells were defective in supporting the formation of B cell colonies from normal individuals.

Defective regulation of B lymphocyte colony formation in patients with systemic lupus erythematosus

We have succeeded in generating B cell colonies from freshly separated human peripheral blood by the double agar layer technique and expanding them in liquid culture for several weeks. Populations of cells enriched in B cells were placed into the upper layer with or without bacterial LPS. Although B cell colonies were observed without LPS, the addition of LPS to the cells in the upper agar layer increased the number of colonies. Also necessary for optimal B cell colony formation was the presence in the lower agar layer of either culture supernatant of PHA-stimulated mononuclear cells or purified T cells and PHA. Without such helper factors in the lower layer, only a few B cell colonies were observed in the upper layer. By using these techniques, peripheral blood lymphocytes from normal individuals and patients with active systemic lupus erythematosus (SLE) were studied for the generation of B cell colonies. Significantly more B cell colonies were observed in patients with SLE, using either kind of "helper" factor. In addition, T cells from normal individuals and patients were tested for their ability to help B cell colony formation. The SLE T cells were found to be defective in this function relative to normal T cells. Thus, although patients with SLE were hyperactive in forming B cell colonies, thier T cells were defective in supporting the formation of B cell colonies from normal individuals.

Long-term culture and cloning of nontransformed human B lymphocytes

B lymphocyte-enriched cell populations cultured with mitogens in initial suspension cultures formed colonies in soft agar when the same mitogenic agent was present in the lower layer of a two-layer soft agar system. Colony formation depended upon the presence of T cells in the initial culture, and was optimal after an initial 72-h culture with phytohemagglutinin (PHA; 12.5 microliters/ml), pokeweed mitogen (PWM; 2.5 micrograms/ml), or protein A (10 micrograms/ml). The colonies could be picked from the agar and propagated by feeding every 3 d with medium supplemented with a growth factor-containing tissue culture supernate. The growth factor-containing supernate was prepared by stimulating pools of human peripheral blood mononuclear cells for 72 h with PHA or PWM. The lines propagated in this manner were membrane Ig+, lacked sheep erythrocyte rosette-forming ability, and did not ingest latex. They lacked the Epstein-Barr nuclear antigen (EBNA) and had 46 chromosomes. Such lines have been propagated for over 1 yr. One line (BL1) was subjected to limiting dilution cloning and a line, BL1.1, was prepared that contained 96% lambda-bearing cells and no kappa-bearing cells. This line was also EBNA negative. This procedure can thus be used to prepare and clone long-term lines of nontransformed human B lymphocytes.

Immune response to levan. II. T independence of suppression of cross-reactive idiotypes by anti-idiotype antibodies

Pretreatment of BALB/c mice with antisera to a cross-reactive idiotype (E109IdX) expressed on many anti-bacterial levan (BL) and anti-inulin (Inu) antibodies leads to a prolonged suppression in production of IdX-bearing molecules in response to BL immunization. There is a comparable suppression in numbers of plaque-forming cells secreting IdX-bearing anti-BL and anti-Inu molecules. Furthermore, spleen cells from anti-E109IdX pretreated mice are unable to transfer to irradiated recipients the ability to produce IdX-bearing anti-BL and anti-Inu antibodies. These results indicate that the suppressive effect is at the precursor level and not simply a clearance of antibodies bearing the IdX. Suppression of IdX production can be achieved by pretreating nu/nu BALB/c mice with anti-E109IdX antibodies. Furthermore, spleen cells from pretreated mice do not inhibit the capacity of spleen cells from normal mice transferred to irradiated recipients to produce E109IdX in response to BL. This indicates that the suppression of IdX production in the anti-BL system is T independent and probably represents direct inhibition of precursors by anti-IdX.

Immune Response to Levan

The antibody response of normal adult, of young and of nu/nu BALB/c mice to bacterial levan was characterized in terms of its relative specificity for levan and for inulin and of the expression of a family of cross-reactive idiotypes (IdX) found on BALB/c myeloma proteins which bind inulin and levan. Normal adult BALB/c mice immunized with levan develop prompt antibody responses which can be detected by serum hemagglutinin assays or by enumeration of plaque-forming cells. These antibodies are specific for levan and many also bind inulin. In addition, the IdX is expressed on a substantial fraction of the anti-levan antibodies, particularly those that bind both inulin and levan. The response to levan is thymus independent in that nu/nu BALB/c mice and lethally irradiated BALB/c mice reconstituted only with bone marrow cells produce anti-levan antibodies. However, the response of nu/nu BALB/c mice to levan is unusual in that the titer of anti-inulin antibodies and of serum IdX is very low. When young mice (2 to 4 weeks of age) are immunized with levan they respond quite well, but their anti-levan antibodies also fail to bind inulin or to express the IdX. These results suggest that the unusual specificity of the response of nu/nu BALB/c mice may reflect the need for a functional thymus in the normal maturation of the thymus-independent lymphocytes which respond to levan with the secretion of antibodies that bind inulin and express the IdX.

Finally, cells secreting antibodies specific for the IdX are regularly observed in the spleens of mice immunized with bacterial levan. This is consistent with regulation of the anti-levan response by autoanti-idiotype antibodies.