Rituximab-treated lymphoma patients develop strong CD8 T-cell responses following COVID-19 vaccination

B‐cell depletion induced by anti‐cluster of differentiation 20 (CD20) monoclonal antibody (mAb) therapy of patients with lymphoma is expected to impair humoral responses to severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) vaccination, but effects on CD8 T‐cell responses are unknown. Here, we investigated humoral and CD8 T‐cell responses following two vaccinations in patients with lymphoma undergoing anti‐CD20‐mAb therapy as single agent or in combination with chemotherapy or other anti‐neoplastic agents during the last 9 months prior to inclusion, and in healthy age‐matched blood donors. Antibody measurements showed that seven of 110 patients had antibodies to the receptor‐binding domain of the SARS‐CoV‐2 Spike protein 3–6 weeks after the second dose of vaccination. Peripheral blood CD8 T‐cell responses against prevalent human leucocyte antigen (HLA) class I SARS‐CoV‐2 epitopes were determined by peptide‐HLA multimer analysis. Strong CD8 T‐cell responses were observed in samples from 20/29 patients (69%) and 12/16 (75%) controls, with similar median response magnitudes in the groups and some of the strongest responses observed in patients. We conclude that despite the absence of humoral immune responses in fully SARS‐CoV‐2‐vaccinated, anti‐CD20‐treated patients with lymphoma, their CD8 T‐cell responses reach similar frequencies and magnitudes as for controls. Patients with lymphoma on B‐cell depleting therapies are thus likely to benefit from current coronavirus disease 2019 (COVID‐19) vaccines, and development of vaccines aimed at eliciting T‐cell responses to non‐Spike epitopes might provide improved protection.

Structural Basis for Regulated Proteolysis by the α-Secretase ADAM10

Cleavage of membrane-anchored proteins by ADAM (a disintegrin and metalloproteinase) endopeptidases plays a key role in a wide variety of biological signal transduction and protein turnover processes. Among ADAM family members, ADAM10 stands out as particularly important because it is both responsible for regulated proteolysis of Notch receptors and catalyzes the non-amyloidogenic α-secretase cleavage of the Alzheimer's precursor protein (APP). We present here the X-ray crystal structure of the ADAM10 ectodomain, which, together with biochemical and cellular studies, reveals how access to the enzyme active site is regulated. The enzyme adopts an unanticipated architecture in which the C-terminal cysteine-rich domain partially occludes the enzyme active site, preventing unfettered substrate access. Binding of a modulatory antibody to the cysteine-rich domain liberates the catalytic domain from autoinhibition, enhancing enzymatic activity toward a peptide substrate. Together, these studies reveal a mechanism for regulation of ADAM activity and offer a roadmap for its modulation.

Extension of research data repository system to support direct compute access to biomedical datasets: enhancing Dataverse to support large datasets

Access to experimental X-ray diffraction image data is important for validation and reproduction of macromolecular models and indispensable for the development of structural biology processing methods. In response to the evolving needs of the structural biology community, we recently established a diffraction data publication system, the Structural Biology Data Grid (SBDG, data.sbgrid.org), to preserve primary experimental datasets supporting scientific publications. All datasets published through the SBDG are freely available to the research community under a public domain dedication license, with metadata compliant with the DataCite Schema (schema.datacite.org). A proof-of-concept study demonstrated community interest and utility. Publication of large datasets is a challenge shared by several fields, and the SBDG has begun collaborating with the Institute for Quantitative Social Science at Harvard University to extend the Dataverse (dataverse.org) open-source data repository system to structural biology datasets. Several extensions are necessary to support the size and metadata requirements for structural biology datasets. In this paper, we describe one such extension-functionality supporting preservation of file system structure within Dataverse-which is essential for both in-place computation and supporting non-HTTP data transfers.

Data publication with the structural biology data grid supports live analysis

Access to experimental X-ray diffraction image data is fundamental for validation and reproduction of macromolecular models and indispensable for development of structural biology processing methods. Here, we established a diffraction data publication and dissemination system, Structural Biology Data Grid (SBDG; data.sbgrid.org), to preserve primary experimental data sets that support scientific publications. Data sets are accessible to researchers through a community driven data grid, which facilitates global data access. Our analysis of a pilot collection of crystallographic data sets demonstrates that the information archived by SBDG is sufficient to reprocess data to statistics that meet or exceed the quality of the original published structures. SBDG has extended its services to the entire community and is used to develop support for other types of biomedical data sets. It is anticipated that access to the experimental data sets will enhance the paradigm shift in the community towards a much more dynamic body of continuously improving data analysis.

Mutual remodeling and conformation grid: a mediator code?

How does a common RNA polymerase II apparatus generate a complex pattern of transcripts in response to many gene-specific transcription factors and in accordance with cell's state? In this issue of Structure, Cai et al. reveal that the process involves coordinated conformational changes in Pol II and Mediator.

A dual interface determines the recognition of RNA polymerase II by RNA capping enzyme

RNA capping enzyme (CE) is recruited specifically to RNA polymerase II (Pol II) transcription sites to facilitate cotranscriptional 5'-capping of pre-mRNA and other Pol II transcripts. The current model to explain this specific recruitment of CE to Pol II as opposed to Pol I and Pol III rests on the interaction between CE and the phosphorylated C-terminal domain (CTD) of Pol II largest subunit Rpb1 and more specifically between the CE nucleotidyltransferase domain and the phosphorylated CTD. Through biochemical and diffraction analyses, we demonstrate the existence of a distinctive stoichiometric complex between CE and the phosphorylated Pol II (Pol IIO). Analysis of the complex revealed an additional and unexpected polymerase-CE interface (PCI) located on the multihelical Foot domain of Rpb1. We name this interface PCI1 and the previously known nucleotidyltransferase/phosphorylated CTD interface PCI2. Although PCI1 and PCI2 individually contribute to only weak interactions with CE, a dramatically stabilized and stoichiometric complex is formed when PCI1 and PCI2 are combined in cis as they occur in an intact phosphorylated Pol II molecule. Disrupting either PCI1 or PCI2 by alanine substitution or deletion diminishes CE association with Pol II and causes severe growth defects in vivo. Evidence from manipulating PCI1 indicates that the Foot domain contributes to the specificity in CE interaction with Pol II as opposed to Pol I and Pol III. Our results indicate that the dual interface based on combining PCI1 and PCI2 is required for directing CE to Pol II elongation complexes.

Structure of the 12-subunit RNA polymerase II refined with the aid of anomalous diffraction data

RNA polymerase II (Pol II) is the central enzyme of eukaryotic gene expression machinery. Complete definition of the three-dimensional structure of Pol II is essential for understanding the mechanisms that regulate transcription via protein-protein interactions within the Pol II apparatus. To date a series of Pol II-related crystal structures have been reported. However, certain peptide regions, including several that are implicated to interact with regulatory factors, remain obscure. Here we describe conformations for two such regions that are close to the Pol II surface and assume seemingly flexible loop structures. One is located in the TFIIF-interacting Protrusion domain, whereas the other is in the TFIIE-interacting Clamp domain. This structural definition was aided by the application of an advanced crystallographic refinement approach that utilizes the single anomalous diffraction (SAD) from zinc ions bound intrinsically in Pol II. The SAD-based strategy allowed the 12-subunit Pol II model to be fully refined up to 3.8 A with excellent stereochemical properties, demonstrating the effectiveness of the SAD approach for the refinement of large structures at low-to-moderate resolutions. Our results also define additional components of the free Pol II, including the functionally critical Fork Loop-1 and Fork Loop-2 elements. As such, this refined Pol II model provides the most complete structural reference for future analyses of complex structures formed between Pol II and its regulatory factors.

Phasing RNA Polymerase II Using Intrinsically Bound Zn Atoms: An Updated Structural Model

Macromolecular assemblies as large as RNA polymerase II (Pol II) can be phased by a few intrinsically bound Zn atoms, by using MAD experiments as described here. A phasing effectiveness of 570 aa/Zn is attained for Pol II. The resulting experimental, unbiased electron density map is of such quality that it confirms the existing crystallographic model and further reveals structural regions not shown by model phases, thus updating the Pol II model at three sites. The mechanistically important fork loop-1 element is observed to be ordered in the absence of nucleic acids, suggesting additional insights into the mechanisms that maintain the stability of the transcription ternary complex and allow its release. Furthermore, a computational experiment with simulated MAD data sets demonstrates that 1 Zn site is able to provide adequate experimental phase information for as many as 1100 amino acids of polypeptide, under the conditions of the current synchrotron and detector technologies.

Antiepiligrin (laminin 5) cicatricial pemphigoid complicated and exacerbated by herpes simplex virus type 2 infection

A 50-year-old man with antiepiligrin (laminin 5) cicatricial pemphigoid (AeCP) involving the eyes, mouth and skin required a combination of systemic drug therapies to suppress the ocular disease. Herpes simplex virus type 2 infection of the mouth and pharynx precipitated an acute deterioration, with laryngeal involvement and an increase in oral ulceration. This is an unusual complication of long-term immunosuppression and illustrates some of the difficulties in the management of patients with AeCP. Clinical improvement was obtained with oral antiviral therapy and adjustment of his immunosuppressive regimen.

Mumps surveillance: results of improved case investigation and serologic testing of suspected cases, Texas, 1995-1996

Mumps, one of several once common childhood diseases, is targeted for elimination in the United States by 2010. To improve its ability to monitor mumps cases, the Texas Department of Health began requiring investigation and serologic testing of all mumps reports. During 1995-1996, of 500 mumps reports, only 14.4 percent were confirmed cases and they had a different demographic profile than unconfirmed cases. To accurately assess whether the nation achieves the Year 2010 mumps elimination goal, and to effectively direct elimination efforts, states must investigate and serologically confirm all mumps reports and use the case definition for public health surveillance.

National serologic survey of measles immunity among persons 6 years of age or older, 1988-1994

CONTEXT

Measles incidence in the United States is at a record low, and indigenous transmission has been interrupted in each year since 1996, suggesting that measles is no longer endemic. A national estimate of measles immunity and an understanding of predictors of measles susceptibility are essential for assuring sustained elimination of endemic disease.

OBJECTIVE

To assess patterns of immunity and to determine predictors of susceptibility to measles.

DESIGN/SETTING

Sera and data on participants from the third National Health and Nutrition Examination Survey (1988-1994) (NHANES III) were examined. NHANES III was a cross-sectional survey of a representative sample of the civilian, noninstitutionalized population of the United States.

POPULATION

20,100 persons 6 years of age or older were tested for measles-specific immunoglobulin G (IgG) antibody by an enzyme immunoassay.

MAIN OUTCOME MEASURE

Participants with serum positive for measles antibody were considered protected or immune to measles disease.

RESULTS

Prevalence of measles immunity was 93%. Nearly all persons (99%) born in the prevaccine era (before 1957) were immune. Immunity declined among persons born in the vaccine era (after 1956) to 81% among those born in 1967-1976, and increased again to 89% among those born in 1977-1988. Among persons born in the vaccine era, independent predictors of measles susceptibility varied by birth cohort and included birth in the United States, residence in a noncrowded household, residence in a nonmetropolitan area, and, among males, non-Hispanic white and Mexican American race/ethnicity. Among adults 17 years of age or older, additional predictors of susceptibility included living at or above the poverty line and not currently being married.

CONCLUSIONS

Population immunity among persons 6 years of age or older is very high; however, as many as 15 million persons across the United States may lack humoral immunity. While it is unclear that the susceptible population can support continuous, indigenous transmission of measles, providers should follow current recommendations to evaluate the measles susceptibility of patients born in the vaccine era and vaccinate eligible patients.

Varicella mortality: trends before vaccine licensure in the United States, 1970-1994

We examined varicella deaths in the United States during the 25 years before vaccine licensure and identified 2262 people who died with varicella as the underlying cause of death. From 1970 to 1994, varicella mortality declined, followed by an increase. Mortality rates were highest among children; however, adult varicella deaths more than doubled in number, proportion, and rate per million population. Despite declining fatality rates, in 1990-1994, adults had a risk 25 times greater and infants had a risk 4 times greater of dying from varicella than did children 1-4 years old, and most people who died of varicella were previously healthy. Varicella deaths are now preventable by vaccine. Investigation and reporting of all varicella deaths in the United States is needed to accurately document deaths due to varicella, to improve prevention efforts, and to evaluate the vaccine's impact on mortality.

Cerebral vasculitis--recognition, diagnosis and management

Cerebral vasculitis is a serious but uncommon condition which presents considerable difficulties in recognition, diagnosis and treatment. We studied eight consecutive patients in whom this diagnosis was made. Despite the great diversity of symptoms and signs, we noted three clinical patterns: (i) acute or sub-acute encephalopathy, (ii) a picture with some similarities to multiple sclerosis ('MS-plus'), and (iii) features of a rapidly progressive space-occupying lesion. The identification of these patterns may help recognition of cerebral vasculitis. The diagnostic value of four investigative procedures not previously studied in cerebral vasculitis was assessed: ophthalmological examination using low-dose fluorescein angiography with slit-lamp video microscopy of the anterior segment (abnormal in 4/5 patients); spinal fluid oligoclonal band analysis (abnormal in 3/6 patients); anti-neutrophil cytoplasmic antibody assay (abnormal in 3/8 patients); and indium-labelled white-cell cerebral imaging (positive in only one patient). Treatment was with steroid alone (n = 2) or steroid with cyclophosphamide (n = 6). Seven patients responded clinically.

Monoclonal antibody therapy of chronic intraocular inflammation using Campath-1H

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Prevention of immune-mediated corneal graft destruction with the anti-lymphocyte monoclonal antibody, CAMPATH-1H

We report a patient with peripheral rheumatoid corneal melting who developed a corneal perforation in one eye requiring tectonic keratoplasty. Nine consecutive corneal grafts were rapidly destroyed despite systemic immunosuppression with corticosteroid, cyclophosphamide, azathioprine and cyclosporin A. A rejection episode was observed in one graft before it melted and allograft rejection may have contributed to the destruction of other grafts. Corneal graft survival was ultimately achieved by systemic immunosuppression with the anti-lymphocyte monoclonal antibody, CAMPATH-1H. A single episode of rejection developed in the early post-operative period which was easily reversed by topical corticosteroid. Corneal melting has not recurred and the graft has now remained intact and clear for 24 months. Anti-lymphocyte monoclonal antibodies may therefore provide effective immunosuppression in the treatment of refractory ocular disorders.

The clinical technician as a member of the patient-focused healthcare delivery team

Change is an integral component of hospital operations. The patient care delivery system is not exempt from the forces of change. Ingalls Memorial Hospital has developed the role of the clinical technician to enhance patient-focused care philosophy. This clinical technician program has successfully achieved patient-focused care without physical restructuring; it has increased patient satisfaction, staff satisfaction, continuity, and quality of care.

Completeness of reporting of diagnosed HIV-infected hospital inpatients

To assess the completeness of human immunodeficiency virus (HIV) reporting among hospital inpatients whose records listed diagnostic codes for HIV infection but who did not meet the 1987 AIDS case definition, we conducted a statewide hospital study of admissions between January 1, 1986 and December 31, 1990. Of the 396 HIV-infected hospital inpatients identified, 313 (79%) had been reported to the State HIV Registry. HIV reporting was less complete for patients who were older and/or were blood product recipients. Of the 313 reported patients, 189 (60%) had been reported prior to their first hospital admission. Temporal improvements were noted in the completeness of HIV reporting among the hospital patients (1986: 65%; 1987: 81%; 1988: 64%; 1989: 82%; 1990: 86%; Chi square for linear trend 9.6, p < 0.01) and prior to their first hospital admission (1986: 31%; 1987: 34%; 1988: 49%; 1989: 64%; 1990: 72%; Chi square for linear trend 26.6; p < 0.01). Women were more likely than men to be reported prior rather than during or after their first hospital admission (71% vs. 55%; p < 0.01). Of the 155 patients with CD4+ T-lymphocyte test results, 41 had CD4+ counts < 200 mm3 and met the 1993 but not the 1987 AIDS case definition. In South Carolina most (79%) diagnosed, hospitalized, HIV-infected patients had been reported to the State HIV REgistry, with improvements in reporting occurring over time. Findings suggest that the 1993 AIDS case definition will improve our ability to monitor severe morbidity related to HIV.

Hereditary C1q deficiency and systemic lupus erythematosus

We describe a 27-year-old women with systemic lupus erythematosus, C1q deficiency and cytomegalovirus retinitis. She suffered from severe SLE, with cutaneous and CNS involvement, and died of CNS disease aged 28. Review of 29 other published cases of C1q deficiency shows that SLE in these patients is often severe (five with CNS disease, ten with glomerulonephritis). The results of autoantibody studies in this and another patient with C1q deficiency and SLE are presented--both patients had autoantibodies to the extractable nuclear antigens, Sm, RNP and Ro, and one patient had high titres of antibodies to dsDNA. One of the patients had previously been treated with fresh frozen plasma, and antibodies to C1q were present in his serum. Homozygous C1q deficiency is associated with a very high prevalence of severe SLE with the full panoply of autoantibodies characteristic of this disease.

Comparison of individuals receiving anonymous and confidential testing for HIV

We assessed the magnitude, demographics, seroprevalence, and reasons for site selection among South Carolina residents who chose to be tested in bordering states offering anonymous testing for human immunodeficiency virus (HIV). Residents tested from July 1990 through July 1991 at selected HIV testing sites in bordering states were surveyed and HIV test results were recorded. Of the 75 residents tested at these sites, 66 (88%) were white, 44 (59%) were male, and 9 (12.3%) of the 73 whose test results were recorded were HIV infected. During the same period, 57,137 individuals were HIV tested in-state by the state health department, of which 1,752 (3.1%) were positive. Residents tested outside the state were more likely to be HIV infected, male, and white than individuals tested within the state. Our findings suggest that although large numbers of South Carolinians are not HIV tested anonymously in other states, those tested anonymously out of state have a different demographic and risk profile than those tested confidentially in state.

Branch retinal artery occlusion in toxoplasma retinochoroiditis

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Diagnosis and management of systemic Wegener's granulomatosis presenting with anterior ocular inflammatory disease

The ocular and systemic features of 10 patients whose Wegener's granulomatosis presented with corneoscleral inflammatory disease are described. Marginal corneal infiltrates were seen in all patients with anterior scleritis and were a valuable sign of disease activity. Nine out of 10 patients had symptoms of systemic vasculitis on presentation; seven had renal impairment; three had chest x-ray abnormalities. Autoantibodies against neutrophil cytoplasmic determinants (ANCA) were present in all cases. In seven patients the scleritis responded well to pulsed immunosuppressive therapy followed by long term oral steroids and cyclophosphamide. Oral steroid therapy alone failed to control severe disease. Corneoscleral disease was not a cause of visual loss. It is important to realise that inflammatory corneoscleral disease may be the presenting feature of a severe systemic vasculitis.

Computer assisted analysis of fluorescein videoangiograms

The efficient analysis of fluorescein videoangiograms requires immediate access to any frame in a video sequence and complete control over the time base during replay. It should also be possible to compare any two frames by rapid subtraction or to subtract any phase of the study from the remaining sequence. A program that performs all these tasks has been written for a low priced desk-top microcomputer. This should facilitate the clinical introduction of fluorescein videoangiography.

The circulation of the human limbus

The superficial circulations of the anterior segment of the human eye have been studied by the following techniques: photographic and video low-dose fluorescein angiography, video-microscopy using red-free light and stereoscopic colour photography. The results are combined to give a dynamic description of the limbal circulation, including its arterial supply and venous drainage.

Patterns of blood flow in episcleral vessels studied by low-dose fluorescein videoangiography

The blood supply of the ocular anterior segment arises from a saggittal arterial ring composed of the long posterior ciliary arteries, the muscular and anterior ciliary arteries and perforating scleral arteries. This ring supplies coronal arterial circles within and outside the globe. Low dose anterior segment fluorescein videoangiography demonstrates arterial and venous flow, recording its characteristics and direction. Videoangiograms were performed at low and high magnification in 15 normal subjects. Episcleral arteries and veins were distinguishable by the presence or absence of pulsatile flow and by their fluorescence intensity. Arteries usually perfused earlier than veins, and with higher flow velocity. Twenty-five of 40 arteries flowed away from scleral perforations close to the limbus. All 8 veins drained away from the limbus. The communication between two arteries may be demonstrated by a static, pulsating column of non-fluoresceinated blood. This sign arose at a point of scleral perforation, at the junction between muscular and anterior ciliary arteries and in the episcleral anterior circle. It supports the concept of arterial shunting, both in the saggittal plane and in the superficial coronal circle. Perforating scleral arteries lay anterior to the episcleral arterial circle in superior angiograms and posterior to it in inferior studies. Vessels that had been characterised by videoangiography were identified in stereo colour photographs of angiographic fields. Arteries were best distinguished from veins by their high tortuosity and thick walls. Using these photographic characteristics, the distribution of arteries and veins over the rectus muscles was surveyed in 13 subjects. The incidence of arteries is lowest over the lateral rectus muscle. Veins were concentrated in the vertical meridian and were absent over lateral rectus in 8 subjects. Five intra-operative videoangiograms are reported. Retraction of conjunctiva facilitated imaging of the episcleral vessels and demonstrated arterial communication through a shared capillary bed.

'Pulsed' immunosuppressive therapy in the treatment of immunologically induced corneal and scleral disease

'Pulsed' immunosuppressive therapy, using methylprednisolone with or without cyclophosphamide, has effectively controlled severe destructive corneal and scleral disease that had been unresponsive to oral steroids. Thirty-seven patients have been treated in this manner and the results, complications and possible mechanism of action are discussed.

The observation of immune complex formation and deposition in the eyes of living rabbits

Fluorescence microscopy of the conjunctival and episcleral circulations of the rabbit's eye has revealed for the first time the formation and deposition of intravascular and perivascular immune complexes in undisturbed capillaries in vivo. During intravascular immune complex formation, immune aggregates appear abruptly, at a critical antigen/antibody ratio, and embolize to the arterial side of the capillary bed. This is accompanied by a fall in the circulating platelet count. The emboli disperse over the ensuing 120 min. In frozen sections immune aggregates are coarsely granular and intraluminal at the moment they embolize. However, after they disperse, subendothelial granules of antigen can be found. IgG and C3 are associated with both intraluminal and subendothelial antigen. Perivascular immune complex formation is accompanied by an intense inflammatory response, which is absent after the deposition of an intravascular immune precipitate. The mechanism by which immune complexes may accomplish their transition across the capillary endothelium is discussed.

Low dose fluorescein angiography of the conjunctiva and episclera

By reducing the dose of injected fluorescein its leakage from conjunctival and episcleral capillaries has been minimised. These vessels have been demonstrated with great clarity, and the venous circulation, previously obscured by extravascular fluorescein, has also been revealed. The anatomy of the anterior segment vessels, and the blood flow within them, has been studied in eight normal subjects. The anterior ciliary arteries feed an anterior episcleral arterial circle that has superficial and deep components. This supplies the anterior conjunctival and episcleral circulations, the limbal arcades, and the iris arterioles. Where the superficial arterial circle is deficient, isolated vessels emerge from the deep segments of the circle to supply the episcleral plexus and conjunctival arterioles. Watershed zones between the anterior and posterior territories of the conjunctival and episcleral circulations overlap. They may fluoresce up to 30 seconds after the anterior ciliary arteries. The scope of this technique and the implications of these findings are discussed.

Critique: external comparison of conceptual nursing models

Research by Jacobson on development of a semantic differential for external comparison of conceptual nursing models was reported in 1984. The present article critiques the philosophical stance and the research methods presented in the Jacobson report. Methods of analysis and evaluation of conceptual nursing models are reviewed, and the influences of conceptual nursing models on the structure of the discipline are examined in light of the purposes of the Jacobson study. Issues related to the investigation and use of models in the development of nursing knowledge are discussed.

Macrophage procoagulant activity as a measure of cell-mediated immunity in the mouse

Thioglycollate-induced peritoneal exudate cells (TG-PEC) developed increased procoagulant activity after incubation with lymphokine and lipopolysaccharide (LPS). Dilutions of up to 1/1000 for insoluble Con A and 1/200 for periodate-induced lymphokine supernatants were active in enhancing macrophage procoagulant activity (MPCA), which was detected after a 2-hr incubation period and steadily increased over 20 hr. MPCA could also be induced by antigen; peritoneal cells from sensitized B6AF1 mice with strong footpad reactions to ovalbumin (OVA) responded to as little as 0.1 microgram/ml OVA in the MPCA test in an antigen-specific manner. By contrast, PEC from sensitized CBA/J mice that gave poor in vivo responses to OVA only reacted with high concentrations of the antigen in vitro. Production of the lymphokine responsible for induction of MPCA required an Ly-1+2- T cell, a nylon wool-adherent cell, and an la-17-bearing adherent cell. The MPCA induced by lymphokine or LPS did not appear to be a serine esterase and was not inhibited by phospholipase C. Coagulation of human factor-deficient plasma with activated TG-PEC indicated a requirement for Factor X.

Macrophage procoagulant activity as a measure of cell-mediated immunity in the mouse

Thioglycollate-induced peritoneal exudate cells (TG-PEC) developed increased procoagulant activity after incubation with lymphokine and lipopolysaccharide (LPS). Dilutions of up to 1/1000 for insoluble Con A and 1/200 for periodate-induced lymphokine supernatants were active in enhancing macrophage procoagulant activity (MPCA), which was detected after a 2-hr incubation period and steadily increased over 20 hr. MPCA could also be induced by antigen; peritoneal cells from sensitized B6AF1 mice with strong footpad reactions to ovalbumin (OVA) responded to as little as 0.1 microgram/ml OVA in the MPCA test in an antigen-specific manner. By contrast, PEC from sensitized CBA/J mice that gave poor in vivo responses to OVA only reacted with high concentrations of the antigen in vitro. Production of the lymphokine responsible for induction of MPCA required an Ly-1+2- T cell, a nylon wool-adherent cell, and an la-17-bearing adherent cell. The MPCA induced by lymphokine or LPS did not appear to be a serine esterase and was not inhibited by phospholipase C. Coagulation of human factor-deficient plasma with activated TG-PEC indicated a requirement for Factor X.

Lack of effect of contralateral speech discourse on auditory threshold response behavior

Three pilot experiments were conducted with normal-hearing adults on the effects of contralateral speech discourse on monaural intensive threshold at 1 kc/s. Two voices simultaneously reading dissimilar passages were presented to the non-test ear. Pure tones and speech were led to insert receivers. Threshold assessment was by operant techniques with feedback for correct response. Stimulus presentation and response recording and retrieval were under computer control. Performance was analyzed by threshold central tendencies and variances, by slopes of performance-level curves, and by slopes of curves for response-decision latencies vs level. In Exper. I (N:5), Ss made threshold judgments while in the contralateral ear speech was presented at 30 db SL, in 2-sec samples with 2-25- sec silent intervals intervening. In Exper. II (N:3), the interrupted speech was at levels of -10, 10, 50, and 70 db; in addition, 4 blocks of thresholds were taken at 30 db SL to examine adaptation effects, if any. In Exper. III (N:3), speech was continuous at the levels of 10, 30, 50, and 70 db. None of the characteristics of the speech appeared to affect performance by any of the 3 indices at any level, for any S systematically. It was concluded that inter- and intra-subject variability may be the key to much of the conflicting results in the literature in the area of performance in noise.

Leukocyte procoagulant activity in man: an in vitro correlate of delayed-type hypersensitivity

Human mononuclear leukocytes generate cell-bound procoagulant activity (LPCA) after incubation with an antigen (mumps or tuberculin) to which the donor was previously sensitized. An inhibitor of coagulation appears to be liberated into the extracellular culture fluid during incubation of leukocytes with the sensitizing antigen. Removal of this activity before measuring LPCA resulted in a reliable test that correlated directly with delayed skin reactivity. The assay was particularly sensitive in that cells from weakly sensitized donors who reacted only to high doses of tuberculin (100 TU) in the delayed skin tests produced detectable LPCA in vitro. By contrast cells from weakly sensitized donors did not react to PPD in the lymphocyte blast transformation test or the direct macrophage migration inhibition factor test. The LPCA assay correlated closely with the blast transformation and MIF tests in which cells were used from more strongly sensitized donors who reacted in skin tests with lower doses of tuberculin (1 or 10 TU). The assays were antigen-specific in that cells from donors sensitive to mumps antigen but not to tuberculin reacted only to mumps antigen in vitro. The assay was extremely reproducible; cells from individual donors reacted to the same extent over a period of 8 mo). We propose that the assay system reported here represents an improved method for the measurement of cell-mediated immunity in vitro because it requires fewer donor cells, is technically simpler, and is more sensitive than previously described methods.

Leukocyte procoagulant activity in man: an in vitro correlate of delayed-type hypersensitivity

Human mononuclear leukocytes generate cell-bound procoagulant activity (LPCA) after incubation with an antigen (mumps or tuberculin) to which the donor was previously sensitized. An inhibitor of coagulation appears to be liberated into the extracellular culture fluid during incubation of leukocytes with the sensitizing antigen. Removal of this activity before measuring LPCA resulted in a reliable test that correlated directly with delayed skin reactivity. The assay was particularly sensitive in that cells from weakly sensitized donors who reacted only to high doses of tuberculin (100 TU) in the delayed skin tests produced detectable LPCA in vitro. By contrast cells from weakly sensitized donors did not react to PPD in the lymphocyte blast transformation test or the direct macrophage migration inhibition factor test. The LPCA assay correlated closely with the blast transformation and MIF tests in which cells were used from more strongly sensitized donors who reacted in skin tests with lower doses of tuberculin (1 or 10 TU). The assays were antigen-specific in that cells from donors sensitive to mumps antigen but not to tuberculin reacted only to mumps antigen in vitro. The assay was extremely reproducible; cells from individual donors reacted to the same extent over a period of 8 mo). We propose that the assay system reported here represents an improved method for the measurement of cell-mediated immunity in vitro because it requires fewer donor cells, is technically simpler, and is more sensitive than previously described methods.

Evaluation of auditory sensory memory of mentally retarded and nonretarded persons

Performance of mentally retarded and nonretarded persons was compared in two experiments designed to identify processes of auditory sensory memory. In one study backward masking of pure tones occurred for a group of retarded adolescents; however, no differences in masking functions were obtained for the retarded group and control groups of equal CA and MA. In the second study a gap-detection task was used as an apparent index of echoic trace durability. Since retarded persons were hypothesized to have a less durable echoic trace, the unique prediction was made that they would outperform control subjects on the task. The retarded group was significantly more accurate and exhibited a lower threshold than did the nonretarded, CA-matched control group. The applicability of these tasks for investigations of mental development was noted, and suggestions were made concerning improvements and extensions of the present research. A theoretical model was proposed to incorporate te current pattern of results.

Long-term effectiveness of imagery instructions with retarded persons

The effects of imagery instructions on paired-associate learning efficiency and on the retention of 16 picture pairs were investigated using two groups of EMR individuals with approximate mental ages of 8 and 11 years, respectively. While facilitated list mastery was obtained under imagery instructions, no facilitation was found for 1-week retention performance. However, in learning a new list immediately following the retention task, those individuals who had received imagery instructions during original learning continued to exhibit facilitated learning. These results extend previous work.

The autonomic nerve supply to the ferret's pineal gland studied by electron microscopy

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