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1.
J Eat Disord ; 9(1): 112, 2021 Sep 14.
Article in English | MEDLINE | ID: mdl-34521470

ABSTRACT

BACKGROUND: Early response to treatment has been shown to be a predictor of later clinical outcomes in eating disorders (EDs). Specifically, early weight gain trajectories in anorexia nervosa (AN) have been shown to predict higher rates of later remission in inpatient treatment. However, no study has, as of yet, examined this phenomenon within outpatient treatment of first episode cases of AN or in emerging adults. METHODS: One hundred seven patients with AN, all between the ages of 16 and 25 and with an illness duration of < 3 years, received treatment via the first episode rapid early intervention in eating disorders (FREED) service pathway. Weight was recorded routinely across early treatment sessions and recovery outcomes (BMI > 18.5 kg/m2 and eating psychopathology) were assessed up to 1 year later. Early weight gain across the first 12 treatment sessions was investigated using latent growth mixture modelling to determine distinct classes of change. Follow-up clinical outcomes and remission rates were compared between classes, and individual and clinical characteristics at baseline (treatment start) were tested as potential predictors. RESULTS: Four classes of early treatment trajectory were identified. Three of these classes (n = 95), though differing in their early change trajectories, showed substantial improvement in clinical outcomes at final follow-up. One smaller class (n = 12), characterised by a 'higher' start BMI (> 17) and no early weight gain, showed negligible improvement 1 year later. Of the three treatment responding groups, levels of purging, depression, and patient reported carer expressed emotion (in the form of high expectations and low tolerance of the patient) determined class membership, although these findings were not significant after correcting for multiple testing. A higher BMI at treatment start was not sufficient to predict optimal clinical outcomes. CONCLUSION: First episode cases of AN treated via FREED fit into four distinct early response trajectory classes. These may represent subtypes of first episode AN patients. Three of these four trajectories included patients with substantial improvements 1 year later. For those in the non-response trajectory class, treatment adjustments or augmentations could be considered earlier, i.e., at treatment session 12.


A key feature of anorexia nervosa (AN) is an unhealthily low body weight. Previous studies show that more weight gained early in inpatient treatment leads to better outcomes. This study tried to see if this was also true for outpatients receiving treatment for the first time. All participants were emerging adults between the ages of 16 and 25 who had been ill for less than 3 years. Weight was recorded across the first 12 weekly treatment sessions. Statistics showed that the patients fit roughly into four different groups in early treatment, each with different starting weights and rates of weight gain in the first 12 treatment sessions. The group a patient belonged to could sometimes be predicted by vomiting behaviours, level of depression, and patients' perception of parental tolerance and expectations at the start of treatment. Out of the four groups, three did relatively well 1 year later, but one small group of patients did not. This small group had a higher starting weight than many of the other groups but did not gain any weight across the first 12 sessions. These patients could benefit from a change or increase in the amount or intensity of treatment after the first 12 treatment sessions.

2.
Pharmacogenomics J ; 18(3): 467-473, 2018 05 22.
Article in English | MEDLINE | ID: mdl-29205205

ABSTRACT

Elucidating resistance mechanisms for therapeutic monoclonal antibodies (MAbs) is challenging, because they are difficult to study in non-human models. We therefore developed a strategy to genetically map in vitro drug sensitivity, identifying genes that alter responsiveness to rituximab, a therapeutic anti-CD20 MAb that provides significant benefit to patients with B-cell malignancies. We discovered novel loci with genome-wide mapping analyses and functionally validated one of these genes, CBLB, which causes rituximab resistance when knocked down in lymphoma cells. This study demonstrates the utility of genome-wide mapping to discover novel biological mechanisms of potential clinical advantage.


Subject(s)
Adaptor Proteins, Signal Transducing/genetics , Drug Resistance, Neoplasm/genetics , Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy , Proto-Oncogene Proteins c-cbl/genetics , Rituximab/adverse effects , Antibodies, Monoclonal/administration & dosage , Antibodies, Monoclonal/adverse effects , Antibodies, Monoclonal/genetics , Antigens, CD20/drug effects , Antigens, CD20/immunology , Antineoplastic Agents , Cell Line, Tumor , Drug Resistance, Neoplasm/drug effects , Female , Gene Expression Regulation, Neoplastic/drug effects , Genetic Linkage , Genome, Human/genetics , Humans , Leukemia, Lymphocytic, Chronic, B-Cell/complications , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Male , Rituximab/administration & dosage
3.
Leukemia ; 31(3): 625-636, 2017 03.
Article in English | MEDLINE | ID: mdl-27568520

ABSTRACT

PRDM1/BLIMP-1, a master regulator of plasma-cell differentiation, is frequently inactivated in activated B-cell-like (ABC) diffuse large B-cell lymphoma (DLBCL) patients. Little is known about its genetic aberrations and relevant clinical implications. A large series of patients with de novo DLBCL was effectively evaluated for PRDM1/BLIMP-1 deletion, mutation, and protein expression. BLIMP-1 expression was frequently associated with the ABC phenotype and plasmablastic morphologic subtype of DLBCL, yet 63% of the ABC-DLBCL patients were negative for BLIMP-1 protein expression. In these patients, loss of BLIMP-1 was associated with Myc overexpression and decreased expression of p53 pathway molecules. In addition, homozygous PRDM1 deletions and PRDM1 mutations within exons 1 and 2, which encode for domains crucial for transcriptional repression, were found to show a poor prognostic impact in patients with ABC-DLBCL but not in those with germinal center B-cell-like DLBCL (GCB-DLBCL). Gene expression profiling revealed that loss of PRDM1/BLIMP-1 expression correlated with a decreased plasma-cell differentiation signature and upregulation of genes involved in B-cell receptor signaling and tumor-cell proliferation. In conclusion, these results provide novel clinical and biological insight into the tumor-suppressive role of PRDM1/BLIMP-1 in ABC-DLBCL patients and suggest that loss of PRDM1/BLIMP-1 function contributes to the overall poor prognosis of ABC-DLBCL patients.


Subject(s)
Lymphoma, Large B-Cell, Diffuse/genetics , Lymphoma, Large B-Cell, Diffuse/mortality , Mutation , Repressor Proteins/genetics , Adolescent , Adult , Aged , Aged, 80 and over , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Biomarkers, Tumor , Biopsy , Female , Follow-Up Studies , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Humans , Lymphoma, Large B-Cell, Diffuse/diagnosis , Lymphoma, Large B-Cell, Diffuse/drug therapy , Male , Middle Aged , Neoplasm Staging , Positive Regulatory Domain I-Binding Factor 1 , Prognosis , Repressor Proteins/metabolism , Sequence Deletion , Transcriptome , Treatment Outcome , Young Adult
5.
Vet Comp Oncol ; 11(1): 30-50, 2013 Mar.
Article in English | MEDLINE | ID: mdl-22236332

ABSTRACT

Molecular characterization of tumour cell lines is increasingly regarded as a prerequisite for defining their validity as models of in vivo neoplasia. We present the first comprehensive catalogue of genomic and transcriptional characteristics of five widely used canine lymphoid tumour cell lines. High-resolution microarray-based comparative genomic hybridization defined their unique profiles of genomic DNA copy number imbalance. Multicolour fluorescence in situ hybridization identified aberrant gains of MYC, KIT and FLT3 and deletions of PTEN and CDKN2 in individual cell lines, and also revealed examples of extensive structural chromosome reorganization. Gene expression profiling and RT-PCR analyses defined the relationship between genomic imbalance and transcriptional dysregulation in each cell line, clarifying their relevance as models of discrete functional pathways with biological and therapeutic significance. In combination, these data provide an extensive resource of molecular data for directing the appropriate use of these cell lines as tools for studying canine lymphoid neoplasia.


Subject(s)
Dog Diseases/metabolism , Gene Expression Regulation, Neoplastic/physiology , Lymphoma/metabolism , Animals , Cell Line, Tumor , DNA/genetics , DNA/metabolism , Dogs , Flow Cytometry , Karyotype , Neoplasm Proteins/genetics , Neoplasm Proteins/metabolism , RNA/genetics , RNA/metabolism , Real-Time Polymerase Chain Reaction/veterinary , Transcriptome
6.
Neuroscience ; 166(1): 195-200, 2010 Mar 10.
Article in English | MEDLINE | ID: mdl-20006674

ABSTRACT

Sodium channel alpha subunit genes expressed in the human brain, SCN1A, SCN2A, SCN3A and SCN8A, are subject to alternative splicing of coding exons 5N and 5A. In this study we examined expression of alpha subunit mRNA and exon 5 splicing in the developing mouse brain. Expression levels of Scn1a, Scn2a and Scn8a mRNAs increase postnatally, whereas Scn3a mRNA expression levels decrease. Scn1a mRNA contains only exon 5A, due to the absence of exon 5N in the mouse Scn1a gene. At birth, Scn2a is the only sodium channel alpha subunit mRNA that contains higher or equal amounts of the 5N isoform compared to the 5A isoform in most brain regions. In contrast, the predominant isoform of Scn3a and Scn8a mRNAs in the newborn mouse brain is 5A. 5N/5A ratios for each of the three mRNAs vary across brain regions, with cortex >or= hippocampus>thalamus>cerebellum. In all brain regions and for all three alpha subunits, 5N/5A ratios gradually decrease with age, levelling at a value between 0.1 and 0.2. These findings suggest potential involvement of common factors in the alternative splicing of exon 5 for all three transcripts, and that expression of these factors varies between brain regions and changes during development. Differences in the strength of exon 5N and/or exon 5A splice sites in Scn2a pre-mRNA as compared to Scn1a and Scn8a may underlie the observed differences in 5N/5A ratios in the three alpha subunit mRNAs.


Subject(s)
Brain/growth & development , Brain/metabolism , Gene Expression Regulation, Developmental/physiology , Protein Subunits/genetics , RNA, Messenger/genetics , Sodium Channels/genetics , Alternative Splicing/genetics , Animals , Animals, Newborn , Brain/anatomy & histology , Exons/genetics , Male , Mice , Mice, Inbred C57BL , NAV1.1 Voltage-Gated Sodium Channel , NAV1.2 Voltage-Gated Sodium Channel , NAV1.6 Voltage-Gated Sodium Channel , Nerve Tissue Proteins/chemistry , Nerve Tissue Proteins/genetics , Nerve Tissue Proteins/metabolism , Protein Isoforms/chemistry , Protein Isoforms/genetics , Protein Isoforms/metabolism , Protein Subunits/chemistry , Protein Subunits/metabolism , RNA Splice Sites/genetics , RNA, Messenger/metabolism , Sodium Channels/chemistry , Sodium Channels/metabolism
7.
Neuroscience ; 148(1): 164-74, 2007 Aug 10.
Article in English | MEDLINE | ID: mdl-17629415

ABSTRACT

Two novel mutations (R85C and R85H) on the extracellular immunoglobulin-like domain of the sodium channel beta1 subunit have been identified in individuals from two families with generalized epilepsy with febrile seizures plus (GEFS+). The functional consequences of these two mutations were determined by co-expression of the human brain NaV1.2 alpha subunit with wild type or mutant beta1 subunits in human embryonic kidney (HEK)-293T cells. Patch clamp studies confirmed the regulatory role of beta1 in that relative to NaV1.2 alone the NaV1.2+beta1 currents had right-shifted voltage dependence of activation, fast and slow inactivation and reduced use dependence. In addition, the NaV1.2+beta1 current entered fast inactivation slightly faster than NaV1.2 channels alone. The beta1(R85C) subunit appears to be a complete loss of function in that none of the modulating effects of the wild type beta1 were observed when it was co-expressed with NaV1.2. Interestingly, the beta1(R85H) subunit also failed to modulate fast kinetics, however, it shifted the voltage dependence of steady state slow inactivation in the same way as the wild type beta1 subunit. Immunohistochemical studies revealed cell surface expression of the wild type beta1 subunit and undetectable levels of cell surface expression for both mutants. The functional studies suggest association of the beta1(R85H) subunit with the alpha subunit where its influence is limited to modulating steady state slow inactivation. In summary, the mutant beta1 subunits essentially fail to modulate alpha subunits which could increase neuronal excitability and underlie GEFS+ pathogenesis.


Subject(s)
Brain Chemistry/genetics , Epilepsy, Generalized/genetics , Genetic Predisposition to Disease/genetics , Mutation/genetics , Seizures, Febrile/genetics , Sodium Channels/genetics , Action Potentials/genetics , Brain/metabolism , Brain/physiopathology , Cell Line , Epilepsy, Generalized/metabolism , Epilepsy, Generalized/physiopathology , Humans , Ion Channel Gating/genetics , Membrane Potentials/genetics , NAV1.1 Voltage-Gated Sodium Channel , Nerve Tissue Proteins/genetics , Patch-Clamp Techniques , Protein Subunits/genetics , Seizures, Febrile/metabolism , Seizures, Febrile/physiopathology , Synapses/genetics , Synapses/metabolism , Synaptic Transmission/genetics , Transfection , Voltage-Gated Sodium Channel beta-1 Subunit
8.
Mol Biol Cell ; 11(5): 1887-903, 2000 May.
Article in English | MEDLINE | ID: mdl-10793159

ABSTRACT

A comprehensive set of clustered charged-to-alanine mutations was generated that systematically alter TUB1, the major alpha-tubulin gene of Saccharomyces cerevisiae. A variety of phenotypes were observed, including supersensitivity and resistance to the microtubule-destabilizing drug benomyl, lethality, and cold- and temperature-sensitive lethality. Many of the most benomyl-sensitive tub1 alleles were synthetically lethal in combination with tub3Delta, supporting the idea that benomyl supersensitivity is a rough measure of microtubule instability and/or insufficiency in the amount of alpha-tubulin. The systematic tub1 mutations were placed, along with the comparable set of tub2 mutations previously described, onto a model of the yeast alpha-beta-tubulin dimer based on the three-dimensional structure of bovine tubulin. The modeling revealed a potential site for binding of benomyl in the core of beta-tubulin. Residues whose mutation causes cold sensitivity were concentrated at the lateral and longitudinal interfaces between adjacent subunits. Residues that affect binding of the microtubule-binding protein Bim1p form a large patch across the exterior-facing surface of alpha-tubulin in the model. Finally, the positions of the mutations suggest that proximity to the alpha-beta interface may account for the finding of synthetic lethality of five viable tub1 alleles with the benomyl-resistant but otherwise entirely viable tub2-201 allele.


Subject(s)
Fungal Proteins/chemistry , Fungal Proteins/metabolism , Saccharomyces cerevisiae Proteins , Saccharomyces cerevisiae/metabolism , Tubulin/chemistry , Tubulin/metabolism , Animals , Benomyl/metabolism , Binding Sites , Cattle , Cell Cycle Proteins/metabolism , Cold Temperature , Fungal Proteins/genetics , Microtubule Proteins/metabolism , Microtubules/metabolism , Models, Molecular , Multigene Family , Mutation , Phenotype , Protein Conformation , Saccharomyces cerevisiae/physiology , Structure-Activity Relationship , Tubulin/genetics
9.
J Rheumatol ; 26(8): 1727-33, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10451069

ABSTRACT

OBJECTIVE: To determine the clinical significance of elevated serum levels of VH4-34 encoded antibodies (VH4-34 Ab) with respect to the diagnosis and clinical characteristics of systemic lupus erythematosus (SLE). METHODS: Ninety-five patients with SLE and 344 controls were studied. The controls included 34 healthy individuals, 282 patients with nonautoimmune diseases, and 28 patients with autoimmune diseases other than SLE. VH4-34 Ab levels were measured by inhibition ELISA using anti-idiotope monoclonal antibody (9G4). SLE disease activity, severity, and damage were assessed by visual analog scales, Systemic Lupus Activity Measure, Lupus Severity of Disease Index, and Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index. RESULTS: Fifty-two of 95 patients with SLE had elevated levels of VH4-34 Ab compared to 18 of 344 controls (5%), giving a sensitivity of 55% and a specificity of 95% for elevated VH4-34 Ab as a serologic test for SLE. The positive predictive value of elevated VH4-34 under these conditions was 74-85%. In this study, anti-dsDNA was not VH4-34 encoded. Significant correlations between VH4-34 and disease activity and severity indices were observed (r = 0.29-0.50). The relative risk for severe disease in SLE patients with VH4-34 antibody level in the highest tertile compared to the lowest tertile was 5.25. Twenty-five of 29 patients with lupus nephritis and 6 of 6 patients with central nervous system (CNS) lupus had elevated VH4-34 Ab. CONCLUSION: With a specificity of 94-95%, the VH4-34 antibody assay may prove valuable as a confirmatory diagnostic test for SLE. In patients with known SLE, serum VH4-34 Ab levels correlate with overall disease severity and activity, but not damage, and with nephritis and CNS lupus.


Subject(s)
Autoantibodies/immunology , Lupus Erythematosus, Systemic/diagnosis , Antibodies, Antinuclear/immunology , Antibody Specificity , Autoantibodies/genetics , Biomarkers , Disease Progression , Female , Humans , Lupus Erythematosus, Systemic/immunology , Male , Sensitivity and Specificity , Serologic Tests
10.
Pept Res ; 7(4): 207-17, 1994.
Article in English | MEDLINE | ID: mdl-7696840

ABSTRACT

Different physicochemical properties of the constituent amino acid side chains have been employed in order to investigate the molecular basis of the experimentally derived retention parameters, S and log k0, of peptides separated by reversed-phase high performance liquid chromatography (RP-HPLC). The results demonstrate that the S-value is strongly related to the total surface area of a peptide but correlates poorly with the corresponding predicted hydrophobicity based on the summated amino acid group retention coefficients. In contrast, the experimentally derived log k0 value correlates well with both the total surface area and the predicted affinity values derived from the incremental free energy of transfer calculated from the summated amino acid retention coefficients. Since the S and log k0 values are parameters useful to the interpretation of peptide and protein chromatographic behavior in RP-HPLC, the results of the present study document the physicochemical relationships that exist between these retention parameters and peptide structure.


Subject(s)
Peptides/chemistry , Peptides/isolation & purification , Chemical Phenomena , Chemistry, Physical , Chromatography, High Pressure Liquid/methods , Protein Conformation , Thermodynamics
11.
Yeast ; 9(3): 295-9, 1993 Mar.
Article in English | MEDLINE | ID: mdl-8488730

ABSTRACT

The Saccharomyces cerevisiae RNA polymerase II subunit gene RPB7 was isolated and sequenced. RPB7 is a single copy gene whose sequence predicts a 19,000 Dalton protein of 171 amino acids. RPB7 is known to dissociate from RNA polymerase II as an RPB4/RPB7 subcomplex in vitro. RPB7 also appears to interact with RNA polymerase II in a manner dependent upon RPB4, since RNA polymerase II purified from cells lacking RPB4 also lacks RPB7. Previous results have demonstrated that deletion of the RPB4 results in slow growth and cold- and temperature-sensitivity. In contrast, deletion of the RPB7 gene revealed that it is essential for cell growth and viability. Loss of both the RPB4 and the RPB7 genes causes lethality. These results suggest that RPB7 contributes to the function of RNA polymerase II in the absence of RPB4 either in a manner independent of its association with the enzyme or by directly binding to the enzyme in a manner independent of its association with RPB4.


Subject(s)
Genes, Fungal/genetics , Genes, Lethal/genetics , RNA Polymerase II/genetics , Saccharomyces cerevisiae/genetics , Amino Acid Sequence , Base Sequence , Cloning, Molecular , Crosses, Genetic , Gene Deletion , Molecular Sequence Data , Polymerase Chain Reaction , Saccharomyces cerevisiae/enzymology , Sequence Analysis
12.
Circulation ; 84(3 Suppl): I182-7, 1991 Sep.
Article in English | MEDLINE | ID: mdl-1884484

ABSTRACT

Doppler and imaging echocardiography are highly useful methods of identifying and quantifying both aortic and pulmonic stenosis. The presence of valve stenosis and associated regurgitation is based on detecting abnormal intracardiac velocity patterns near the affected valve. Defining the specific valve involved and the type of lesion present is based on determining the location and timing of the abnormal velocities. Both color flow imaging and duplex pulsed Doppler with two-dimensional echocardiographic imaging are highly accurate in identifying the lesions present. Quantification of the severity of stenotic lesions requires calculation of the pressure gradient across the valve and estimation of valve area; quantification of volume flow rate is frequently helpful. The pressure gradient is calculated from high velocity data acquired in the stenotic valve orifice by using the Bernoulli equation. Volume flow rate through the valve can be estimated by using Doppler velocity data and two-dimensional echocardiographic imaging data acquired at sites upstream from the stenotic valve. The continuity equation allows calculation of valve area that is based on this noninvasive stroke volume and pressure gradient data. This review characterizes flow patterns present near stenotic valves, discusses the equations required to quantify aortic and pulmonic stenosis, and then describes the clinical approach to the noninvasive quantification of both stenotic lesions.


Subject(s)
Aortic Valve Stenosis/diagnostic imaging , Echocardiography , Pulmonary Valve Stenosis/diagnostic imaging , Echocardiography, Doppler , Humans , Models, Cardiovascular
13.
Proc Natl Acad Sci U S A ; 88(5): 1721-5, 1991 Mar 01.
Article in English | MEDLINE | ID: mdl-11607155

ABSTRACT

Chloroplast transformation of Chlamydomonas reinhardtii has been accomplished by agitating cell wall-deficient cells in the presence of glass beads and DNA. By using the atpB gene as the selected marker and cells grown in 0.5 mM 5-fluorodeoxyuridine, we have recovered up to 50 transformants per microgram of DNA. This method is easy and does not require specialized equipment, although it is not as efficient as the tungsten particle bombardment method [Boynton, J. E., Gillham, N. W., Harris, E. H., Hosler, J. P., Johnson, A. M., Jones, A. R., Randolph-Anderson, B. L., Robertson, D., Klein, T. M., Shark, K. B. & Sanford, J. C. (1988) Science 240, 1534-1537]. By using particle bombardment, we have developed a cotransformation approach in which spectinomycin-resistant 16S rRNA-encoding DNA is the selected marker, and we have demonstrated that cotransformation of an unselected marker on an independent replicon is very efficient. We have used this strategy (i) to recover transformants with partially deleted atpB genes that could not otherwise have been selected since they did not restore photosynthetic capability to a recipient carrying a more extensive atpB deletion and (ii) to generate specific deletion mutations in a wild-type recipient. This methodology should allow the introduction of any desired change into the chloroplast genome, even in the absence of phenotypic selection, and thus a detailed functional analysis of any chloroplast DNA sequence should be possible.

14.
Am Heart J ; 119(4): 905-10, 1990 Apr.
Article in English | MEDLINE | ID: mdl-2321509

ABSTRACT

The Doppler echocardiographic estimation of cardiac output at the mitral valve site is often underestimated in adults with slow heart rates because the mitral valve remains open in mid-diastole when flow is markedly reduced. Therefore we tested several approaches to this measurement in 17 adults with nonvalvular heart disease who had thermodilution catheters in the right side of the heart. Superior correlations with thermal output values were obtained by a new method that excludes mitral orifice measurements during mid-diastole when flow less than 10 cm/sec (r = 0.94) compared with the standard method (r = 0.89). Also, the new method resulted in significantly less underestimation of thermal cardiac output in patients with heart rates less than 70 beats/min (-10%) compared with the standard method (-34%). In addition, use of a constant maximal two-dimensional echocardiographic mitral orifice correction factor of 0.77 with the new method to account for variations in mitral valve orifice during the cardiac cycle, as opposed to 0.68 with the standard method, resulted in similar results as compared with determining individual correction factors from M-mode echoes. We conclude that: (1) the mitral orifice approach is accurate for measuring cardiac output in adult patients with nonvalvular heart disease; (2) a new method that excludes mid-diastolic mitral orifice measurements is superior to the standard method; and (3) use of a constant two-dimensional echocardiographic mitral valve orifice correction factor obviates the need for M-mode echoes.


Subject(s)
Cardiac Output , Echocardiography, Doppler/standards , Echocardiography/standards , Echocardiography, Doppler/methods , Heart Rate/physiology , Humans , Middle Aged , Mitral Valve , Thermodilution
15.
Immunology ; 69(2): 257-63, 1990 Feb.
Article in English | MEDLINE | ID: mdl-2407643

ABSTRACT

Affinity-purified IgA from the serum of an 8-year-old boy with a 5-year history of recurrent facial nodules, intermittent neutropenia and elevated immunoglobulin levels, inhibited the chemotaxis of polymorphonuclear neutrophils (PMN) from both patient and normal adults. Preincubation of normal PMN with IgA from the patient's serum (0.5 mg/ml) inhibited chemotaxis to C5a and to the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (FMLP) by 80%, while IgA or IgG from pooled human serum and IgG from the patient were without effect. Normal PMN chemotaxis was restored after IgA depletion of the patient's serum by affinity chromatography. The patient's IgA, but not IgA from pooled human serum, bound specifically to normal PMN by its antigen-binding sites and recognized a 62,000 MW membrane protein on normal neutrophils, which was distinct from the FMLP receptor, the C5a receptor, or the Fca receptor. Attachment of the patient's IgA to the 62,000 MW protein activated intracellular oxidative metabolism on a parity with phorbol myristate acetate (PMA) and resulted in a significant up-regulation of membrane receptors for FMLP. After the binding of patient (Pt) IgA, normal neutrophils were rendered significantly less responsive to subsequent stimulation with phorbol esters. These results characterize a novel mechanism of chemotactic inhibition by serum IgA and also identify a neutrophil membrane protein that is linked to intracellular oxidative metabolism.


Subject(s)
Chemotaxis, Leukocyte/immunology , Immunoglobulin A/pharmacology , Membrane Proteins/analysis , Child , Complement C5a/metabolism , Fluorescent Antibody Technique , Humans , Male , N-Formylmethionine Leucyl-Phenylalanine/metabolism , Neutrophils/immunology , Neutrophils/metabolism , Oxygen Consumption
16.
Am J Cardiol ; 62(1): 113-6, 1988 Jul 01.
Article in English | MEDLINE | ID: mdl-3381730

ABSTRACT

A total of 135 patients with normally functioning prosthetic aortic valves who were catheterized 6 months after placement of Hancock, modified Hancock or Bjork-Shiley prostheses were studied to determine the magnitude of error in Gorlin formula estimates of prosthetic aortic valve area. All patients were male, selected from 13 participating hospitals and routinely followed after valve replacement for 5 years. Hemodynamically determined Gorlin valve areas were compared with independently verified actual valve areas. Actual Hancock areas were measured from videotapes of valves exercised in a pulse duplicator flow model. Actual Bjork-Shiley areas were calculated directly from the valves' inner ring radius. Gorlin valve areas correlated poorly with actual valve areas (r = 0.39). The mean Gorlin formula error was 0.36 cm2 (standard deviation = 0.32). Gorlin areas overestimated actual areas by greater than 0.25 cm2 in 43 patients (32%) and underestimated actual areas by greater than 0.25 cm2 in 29 (21%). It was concluded that the Gorlin formula inaccurately predicts prosthetic valve area in the aortic position. Overreliance on this formula in assessing aortic stenosis could lead to errant clinical decisions.


Subject(s)
Aortic Valve Stenosis/pathology , Aortic Valve/pathology , Heart Valve Prosthesis , Aortic Valve/physiopathology , Cardiac Catheterization , Cardiac Output , Humans , Videotape Recording
18.
Circulation ; 77(4): 830-6, 1988 Apr.
Article in English | MEDLINE | ID: mdl-3349583

ABSTRACT

It is known that rheumatic heart disease frequently results in isolated mitral regurgitation without concomitant mitral stenosis, especially in countries with a high prevalence of rheumatic fever. However, more recent surgical pathologic data also have demonstrated a high incidence of mitral valve prolapse in cases of rheumatic heart disease, which suggests that rheumatic fever may be a cause of mitral valve prolapse. To determine whether this association of mitral valve prolapse and rheumatic heart disease is present in a stable clinic population, we studied 30 patients who had an apical systolic murmur and a well-documented history of rheumatic fever with dynamic auscultation, two-dimensional echocardiography, and pulsed Doppler examinations. Twenty of the 30 patients (67%) had findings on physical examination consistent with isolated mitral regurgitation and 25 patients (84%) had mitral regurgitation by Doppler examination. Echocardiography demonstrated mitral valve prolapse in 24 patients (80%), whereas only one of the total study group had echocardiographic findings consistent with mitral stenosis. We conclude that (1) the presence of an isolated systolic murmur in patients with a history of rheumatic fever frequently represents pure mitral regurgitation secondary to mitral valve prolapse and (2) postinflammatory changes in valvular tissue resulting from rheumatic fever may be the etiology of mitral valve prolapse in these patients.


Subject(s)
Mitral Valve Prolapse/etiology , Rheumatic Heart Disease/diagnosis , Adult , Echocardiography , Female , Heart Auscultation , Humans , Male , Middle Aged , Mitral Valve Insufficiency/diagnosis , Mitral Valve Insufficiency/etiology , Mitral Valve Prolapse/diagnosis
19.
Circulation ; 77(3): 543-51, 1988 Mar.
Article in English | MEDLINE | ID: mdl-3342485

ABSTRACT

To determine the mechanisms by which blood flow increases across the mitral and aortic valves during exercise, 18 normal men were studied during graded supine and upright bicycle exercise at matched workloads. Mitral valve orifice and ascending aortic blood velocities were recorded by Doppler echocardiography during steady states at each stage of exercise. Parasternal two-dimensional echocardiographic imaging of the ascending aorta adjacent to the aortic valve orifice and the mitral valve orifice at the tips of the valve leaflets was used to calculate changes in cross-sectional area during exercise. Heart rate increased from rest to exercise from 67 to 150 beats/min (124%) during supine exercise and from 72 to 147 beats/min (104%) during upright exercise. Stroke volume increased 20% during supine and 46% during upright exercise; the increase in stroke volume was statistically significant when rest and exercise were compared and when the magnitude of change was compared vs position (p less than .05). The increase in stroke volume measured at the ascending aorta was accomplished by an increase in the velocity-time integral (+15% supine and +48% upright, p less than .05), with little change in aortic cross-sectional area (5% supine and 0% upright, p = NS). By contrast, the increase in flow rate measured at the mitral valve was predominantly due to an increase in mean diastolic cross-sectional area (+29% supine and 34% upright, p less than .05); the velocity-time integral did not increase significantly (-10% supine and 4% upright; p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Aortic Valve/physiology , Cardiac Output , Coronary Circulation , Mitral Valve/physiology , Physical Exertion , Adult , Blood Flow Velocity , Echocardiography , Exercise Test , Heart Rate , Humans , Male , Stroke Volume
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