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PubMed1959

The precipitin reaction between DNA and a serum factor in systemic lupus erythematosus.

The sera of certain patients with systemic lupus erythematosus contain an antibody-like substance capable of reacting with highly purified DNA preparations from widely divergent sources. Precipitin reactions have been demonstrated by double diffusion in agar and quantitative precipitin curves have been obtained. Complement was observed to be fixed in the reaction. Evidence was obtained that the serum factor possessed antigenic properties similar to those of gamma-globulins and migrated with this fraction on zone electrophoresis. The interaction of this factor with DNA exhibited certain specific characteristics which differ considerably from non-specific reactions between DNA and proteins in general. The DNA-precipitating factor appeared to be one of a number of related factors reacting with nuclear constituents of many different cells. It differed in certain respects from the "LE factor" which is responsible for the formation of "LE cells." The accumulated evidence, although not yet conclusive, favors the concept that the precipitating factor represents an antibody to DNA, and that it is one of a number of autoantibodies elicited in this disease.

Antibodies↗
PubMed2000

Non-Mendelian segregation of sex chromosomes in heterospecific Drosophila males.

Interspecific hybrids and backcrossed organisms generally suffer from reduced viability and/or fertility. To identify and genetically map these defects, we introgressed regions of the Drosophila sechellia genome into the D. simulans genome. A female-biased sex ratio was observed in 24 of the 221 recombinant inbred lines, and subsequent tests attributed the skew to failure of Y-bearing sperm to fertilize the eggs. Apparently these introgressed lines fail to suppress a normally silent meiotic drive system. Using molecular markers we mapped two regions of the Drosophila genome that appear to exhibit differences between D. simulans and D. sechellia in their regulation of sex chromosome segregation distortion. The data indicate that the sex ratio phenotype results from an epistatic interaction between at least two factors. We discuss whether this observation is relevant to the meiotic drive theory of hybrid male sterility.

Animals↗
PubMed1977

Vesicular stomatitis virus-infected L1210 murine leukemia cells: increased immunogenicity and altered surface antigens.

Homogenates of L1210 cells infected in vitro with vesicular stomatitis virus (VSV) were immunogenic agains a tumor graft of 100 times the LD50 dose of L1210 cells" whereas those of uninfected cells were not. The immunogenicity of intact X-irradiated L1210 cells was distinguishable from that of VSV-infected cell homogenates on the basis of the susceptibility of immunogenicity to experimental procedures used in preparation of the immunogenic homogenates: Homogenization of intact X-irradiated cells or their infection with VSV prior to irradiation led to loss of immunogenicity. In addition, uninfected cell homogenates were not made immunogenic nor was the immunogenicity of VSV-infected cell homogenates eliminated by X-irradiation. At the time of tumor challenge, sera from mice that were effectively immunized with VSV-infected cell homogenate showed a high VSV-neutralizing titer but no complement-dependent cytotoxicity for L1210 cells. Quantitative absorption studies demonstrated that VSV infection led to a marked reduction in L1210 surface antigens recognized by cytotoxic alloantibody; spatial association between these antigens and VSV antigens was not demonstrable on VSV-infected cells. Antigens recognized by heterologous antiserum to L1210 cells were also reduced following VSV infection.

Animals↗
PubMed2003

Immunotherapy in the prophylaxis and treatment of neonatal sepsis.

Neonatal sepsis is a significant cause of morbidity and mortality in the neonatal intensive care unit. The epidemiology of neonatal infections is complex; however, they are in large part secondary to developmentally immature host defense mechanisms. These immunodeficiencies, which are exaggerated in premature and sick neonates, include quantitative and qualitative deficits in phagocytes, complement components, cytokines, and immunoglobulins. Therapies that modulate or augment host defenses may attenuate the virulence of neonatal infections. In this paper, we have reviewed immunotherapies that modulate the immune system of the neonate, including: intravenous immunoglobulins, myeloid hematopoietic growth factors, and granulocyte transfusions. Future studies should focus on investigating other abnormalities of neonatal host defense and/or combined immunotherapy approaches in an attempt to circumvent the immaturity of host defense and potentially reduce both the incidence and severity of neonatal sepsis.

Granulocyte Colony-Stimulating Factor↗
PubMed1979

Analysis of the Light-harvesting Pigment-Protein Complex of Wild Type and a Chlorophyll-b-less Mutant of Barley.

we have compared chloroplast lamellae isolated from a chlorophyll-b-less mutant and wild type barley (Hordeum vulgare). The results demonstrate that: (a) one of the two major polypeptides comprising the lightharvesting complex (LHC) is present in the chlorophyll-b-less mutant; (b) higher cation concentrations are required to maintain grana stacks in the mutant; and (c) cation effects on excitation energy distribution are present in the chlorophyll-b-less mutant but are reduced in amount and are dependent on higher concentrations of cations.We interpret these data to support the concept that the LHC mediates cation-induced grana stacking and cation regulation of excitation energy distribution between photosystems I and Ii in chloroplast lamellae. A partial LHC complement in the mutant alters the quantitative cation requirement for both phenomena, but not the over-all qualitative response.

Journal Article↗
PubMed1980

Quantitative analysis of 6985 digitized trypsin G-banded human metaphase chromosomes.

The frequency and staining intensity of the dark bands were measured in 6985 trypsin G-banded human chromosomes, described by so-called band transition sequences which represent the chromosome banding patterns in a condensed quantitative way. In the haploid chromosome complement a maximum of 351 bands were registered: 181 white and 170 dark bands. The frequency with which bands occurred and the staining intensity of the bands differed considerably between the chromosome types. Among the dark bands the darker stained bands occurred more frequently than the lighter stained bands. A study of the relationship between the degree of chromosome contraction and the frequency of band occurrence revealed that for all chromosome types the average band frequency increased with increasing chromosome elongation. Twenty of the 23 dark bands chosen as landmarks by the Paris Conference (1971) occurred with high frequency and staining intensity. The remaining three landmarks occurred less frequently, due to fusion of dark and white bands, respectively. A study of global features showed, as expected, good agreement between chromosome length, area and density. there was good agreement between the centromeric indices determined by length and area, respectively, and no difference was found between contracted and elongated chromosomes, with the exception of the acrocentrics where elongated chromosomes showed higher centromeric indices than contracted chromosomes. Most often, the centromeric index by density differed considerably from the centromeric indices by length and area, respectively. The data presented here may be used in clinical cytogenetics as a supplement to the ISCN idiograms (ISCN 1978), as the band frequencies and staining intensities may help in identifying and characterizing specific bands.

Chromosome Banding↗
PubMed1991

Quantitative electroencephalography and anatomoclinical principles of aphasia. A validation study.

No single technology in isolation can provide a full view of the anatomoclinical principles evident in the clinical populations we study. The dynamic nature of quantitative electrophysiology makes it an ideal complement to anatomic and metabolic imaging. The statistical conundrum it has presented may be resolved by the approach incorporated in CART. The intent of this study was to examine QEEG and CART in the evaluation of the neurologic bases of a well-defined behavioral disorder like aphasia. The combined power of QEEG and CART yielded objective electrophysiologic methods to predict aphasia that rival the reliability of the language examination. Such success is unprecedented. This success allows us to incorporate QEEG and CART into our technological armamentarium and to return to the evaluation of less well-understood disorders with confidence in both our findings and anatomoclinical principles we derive from them.

Adolescent↗
PubMedDate not supplied

Anticardiolipin antibodies in South African patients with lupus nephritis: a clinical and renal pathological study.

AIMS: This study was conducted prospectively to ascertain the prevalence of anticardiolipin antibodies (ACAs) in patients with lupus nephritis and to determine whether this subgroup of patients differed clinically and histologically from patients without the antibody. PATIENTS AND METHODS: 40 SLE patients (26 Blacks, 14 Indians, 37 females, 3 males) with evidence of renal involvement underwent clinical assessment and percutaneous renal biopsy. Special investigations included: urinary protein quantitation; radioisotope glomerular filtration rate (GFR); complement levels, and antinuclear antibodies and ACAs. Histology was reviewed by a single senior pathologist blinded to the ACA results. In addition to the standard WHO classification, specimens were examined for intrarenal thrombosis. RESULTS: The prevalence of ACA was 45% (18 of 40 patients). Thrombocytopenia was more frequent in patients with ACA (33 vs. 13.6%, p = 0.015). Patients with ACA did not differ from controls with regard to the incidence of thrombosis, neurological disorders, recurrent fetal loss, active disease and hypertension. Mean GFR and 24-hour urine protein (ACA vs. controls) were 51.3 versus 67 ml/min (NS) and 2.4 versus 3.7 g (NS), respectively. Intrarenal microvascular thrombosis (glomerular and arteriolar) occurred in 27.7% of ACA patients versus 9% of controls (p = 0.025). Apart from a higher incidence of class-III nephritis in the controls, standard histology (WHO classification) did not differ between the 2 groups. CONCLUSION: The prevalence of ACA in our patients with lupus nephritis was 45%. This subgroup did not differ from patients without the antibody apart from a higher incidence of thrombocytopenia and intrarenal microvascular thrombosis.

Adult↗
PubMed1986

A sensitive ELISA for the quantitation of human C5a in blood plasma using a monoclonal antibody.

An ELISA for the quantitation of the C5a anaphylatoxin of complement in human plasma is presented which is based on the use of both a monoclonal antibody and polyclonal antibodies to C5a. Its detection limit is 1 ng C5a/ml plasma. It detects no C5a in fresh EDTA-plasma. Complete removal of C5 by an optimized precipitation step prior to the assay procedure is an essential feature of the method.

Antibodies, Monoclonal↗
PubMed1987

Binding of quinine- and quinidine-dependent drug antibodies to platelets is mediated by the Fab domain of the immunoglobulin G and is not Fc dependent.

The antibody domain controlling reactions between platelet membranes and drug-dependent (dd) antibodies from patients with thrombocytopenia induced by cinchona alkaloids was studied using F(ab')2, Fab, and Fc fragments made from purified dd-IgG. By direct binding radioimmunoassay (RIA) measurements, 20,000 to 50,000 antibody molecules bound per platelet equivalent of purified platelet membranes at apparent saturation with three different antibodies. F(ab')2 and Fab fragments bound to platelet membranes drug dependently but Fc fragments did not. The ability of dd-IgG fragments to compete with intact IgG was quantitatively measured by RIA and by complement fixation. F(ab')2 and Fab competed with intact IgG at an 8:1 and greater than 50:1 molar ratio, respectively, in RIA, and at a 1.6-3:1 and 44-75:1 ratio, respectively, by complement fixation assays. Fc did not compete with IgG in either assay. We conclude that the Fab domain supports attachment of dd antibody to the platelet surface.

Autoantibodies↗
PubMed2006

Measures of response: RECIST, WHO, and new alternatives.

RECIST (Response Evaluation Criteria in Solid Tumors) is a widely employed method introduced in 2000 to assess change in tumor size in response to therapy. The simplicity of the technique, however, contrasts sharply with the increasing sophistication of imaging instrumentation. Anatomically based imaging measurement, although supportive of drug development and key to some accelerated drug approvals, is being pressed to improve its methodologic robustness, particularly in the light of more functionally-based imaging that is sensitive to tissue molecular response such as fluorodeoxyglucose positron emission tomography. Nevertheless ready availability of computed tomography and magnetic resonance imaging machines largely assures anatomically based imaging a continuing role in clinical trials for the foreseeable future. Recent advances in image processing enabled by the computational power of modern clinical scanners open a considerable opportunity to characterize tumor response to therapy as a complement to image acquisition. Various alternative quantitative volumetric approaches have been proposed but have yet to gain wide acceptance by clinical and regulatory communities, nor have these more complex techniques shown incontrovertible evidence of greater reproducibility or predictive value of clinical events and outcome. Unless plans are created for clinical trials that incorporate the design needed to prove the added value and unique clinical utility of these novel approaches, any theoretical benefit of these more elaborate methods could remain unfulfilled.

Artifacts↗
PubMed2006

Variation in the innate and acquired arms of the immune system among five shorebird species.

To contribute to an understanding of the evolutionary processes that shape variation in immune responses, we compared several components of the innate and acquired arms of the immune system in five related, but ecologically diverse, migratory shorebirds (ruff Philomachus pugnax L., ruddy turnstone Arenaria interpres L., bar-tailed godwit Limosa lapponica L., sanderling Calidris alba Pallas and red knot C. canutus L.). We used a hemolysis-hemagglutination assay in free-living shorebirds to assess two of the innate components (natural antibodies and complement-mediated lysis), and a modified quantitative enzyme-linked immunosorbent assay in birds held in captivity to assess the acquired component (humoral antibodies against tetanus and diphtheria toxoid) of immunity. Ruddy turnstones showed the highest levels of both innate and acquired immune responses. We suggest that turnstones could have evolved strong immune responses because they scavenge among rotting organic material on the seashore, where they might be exposed to a particularly broad range of pathogens. Although ruffs stand out among shorebirds in having a high prevalence of avian malaria, they do not exhibit higher immune response levels. Our results indicate that relationships between immune response and infection are not likely to follow a broad general pattern, but instead depend on type of parasite exposure, among other factors.

Analysis of Variance↗
PubMed2006

High-throughput pKa screening and prediction amenable for ADME profiling.

Recent technological advances have made it possible for several new pK(a) assays to be used in drug screening. In this review, a critical overview is provided of current new methodologies for high-throughput screening and prediction of pK(a). Typical applications of using pK(a )constants and charge state for absorption, distribution, metabolism and excretion (ADME) profiling and quantitative structure-activity relationship modelling complements the methodological comparisons and discussions. The experimental methods discussed include high-throughput screening of pK(a) by multiplexed capillary with ultraviolet absorbance detection on a 96-capillary format instrument, capillary electrophoresis and mass spectrometry (CEMS) based on sample pooling, determination of pK(a) by pH gradient high-performance liquid chromatography, and measurement of pK(a) by a mixed-buffer liner pH gradient system. Comparisons of the different experimental assays are made with emphasis on the newly developed CEMS method. The current status and recent progress in computational approaches to pK(a) prediction are also discussed. In particular, the accuracy limits of simple fragment-based approaches as well as quantum mechanical methods are addressed. Examples of pK(a) prediction from in-house drug candidates as well as commercially available drug molecules are shown and an outline is provided for how drug discovery companies can integrate experiments with computational approaches for increased applications for ADME profiling.

Animals↗
PubMed1978

Kinetics of 99MTc-pertechnetate uptake in healthy and arthritic knees.

99mPertechnetate (99TcO-4) was injected intravenously in 7 healthy subjects and 30 patients with rheumatoid arthritis (RA). The uptake of isotope (99Tc) in both knee joint regions was traced continuously for 30 min from the time of injection. The isotope showed more rapid accumulation with increasing arthritic involvement of the knee, and the rate of uptake of 99TcO-4 in the knee region tallied with the clinical findings before and after treatment (14 RA patients). The findings indicate that the rate of 99TcO-4 uptake could serve as a useful complement to the more commonly used quantitative uptake of isotope. The two measures may possibly reflect different features of synovial inflammation.

Adult↗
PubMed2026

Retinal Transcriptome-Wide Association Study Identifies Novel Alzheimer's Disease Risk Genes.

INTRODUCTION: Alzheimer's disease (AD) is the leading cause of dementia worldwide. The retina shares molecular pathways with the brain, yet no study has systematically linked retinal gene expression to AD risk. METHODS: We performed transcriptome-wide association studies (TWAS) using two independent retinal eQTL panels (Strunz et al., n = 311; EyeGEx, n = 406) and a large meta-analyzed AD genome-wide association study (GWAS) (Bellenguez et al., 111,326 cases, 677,663 controls). Genes were further validated with GWAS in the independent Alzheimer's Disease Sequencing Project (ADSP) using a matched eQTL-panel strategy. RESULTS: We identified 62 AD-associated genes across the two eQTL panels using Bellenguez et al. as the discovery cohort. Of these, 31 were replicated in the ADSP cohort. The findings highlight shared complement-mediated immune dysregulation (CD55, CD46, TREM2) and provide functional transcriptomic evidence to prioritize novel causal drivers of AD pathogenesis, including STYX and the LRRC37 gene family. DISCUSSION: Retinal data capture core AD genetic architecture and reveal novel risk genes, highlighting the retina as a molecularly informative tissue for dementia research.

Alzheimer’s disease↗
PubMed1978

Adenocarcinoma of the prostate in perspective.

Adenocarcinoma of the prostate is responsible for one of every nine deaths from cancer in Canada. In this review epidemiologic factors are considered and current staging systems are outlined. The American Urological System is recommended for staging because of its ability to reflect changes in the understanding of the biologic behaviour of this neoplasm. The adoption of a quantitative grading scheme is suggested to complement the information obtained from the staging assessment. The routes of spread of this disease, along with the procedures used to assess metastatic involvement, are described. Immunologic methods for the analysis of prostatic acid phosphatase have been shown to be superior to the enzymatic methods previously used, and the role of the new techniques is discussed. Emphasis is placed on radiotherapy and endocrine therapy for the treatment of this neoplasm, and the concept of withholding endocrine therapy until symptoms appear is discussed. Potential future developments in this field are considered.

Acid Phosphatase↗
PubMed1988

Quantitative analyses of the relationship between C3 consumption, C3b capture, and immune adherence of complement-fixing antibody/DNA immune complexes.

We have studied the turnover of the third component of C (C3) and capture of the major cleavage fragment of C3 produced during C activation (C3b) that occurs when soluble antibody/DNA immune complexes (IC) active C. We used the Amersham RIA kit for the minor cleavage fragment of C3 produced during C activation (C3a), and a new assay utilizing mAb to C3b to measure the fraction of active C3 in a C source after the IC activate C. These mAb, along with a mAb to human IgG, allowed us to measure IC stoichiometries. The efficiency of C3 turnover by the IC is quite high, and under conditions of Ab excess, the maximum number of IgG bound per dsDNA corresponds to 1 IgG/20 to 30 base pairs. The maximum number of C3b found in the IC corresponds to less than 1 C3b/IgG, and the vast majority of the captured C3b is bound to the IgG, and not to the DNA. We identified several IC that consumed large amounts of C3, and captured large amounts of C3b, but did not bind to human E via C3b receptors (C receptor type 1). This finding suggests that the ability of IC to bind to human E depends upon the number and distribution of captured C3b molecules and the conformation and size of the DNA Ag, which reflects the need for multivalent binding between several properly arrayed C3b and a "cluster" of C receptor type 1 on the human E membrane. IC that activate C3 but do not bind to E would presumably "escape" the E IC clearance mechanism, but could deposit in susceptible organs and tissues and play a role in the pathogenesis of SLE because of their potential to generate the inflammatory products of C activation.

Antigen-Antibody Complex↗
PubMed1988

[Familial studies of patients with hereditary angioedema].

25 families with 607 members were studied. 165 persons of them suffer from hereditary angioneurotic edema and 28 persons had died from this disease. The clinical forms of the disease are discussed. A classification of angioneurotic edema caused by C-inactivator deficiency is presented. The importance of the examination of C1 inactivator (quantitatively and qualitatively) and of C4 complement fraction in patients with hereditary angioneurotic edema is pointed out.

Adolescent↗