Biomedical subjects

M A Shaughnessy

Publications and source records attributed to M A Shaughnessy.

At least 19 recordsLinked to original sources

PubMed2000

Lymphocyte subsets and activation markers in patients with acute episodes of idiopathic anaphylaxis.

BACKGROUND: Idiopathic anaphylaxis (IA), a type of anaphylaxis in which no external allergen can be identified, is a corticosteroid-responsive disease, that suggests that it may have an immunologic pathogenesis. OBJECTIVE: The objective of this study is to compare patients with acute episodes of IA with normals, patients with chronic idiopathic urticaria, and patients with IA in remission relative to lymphocyte subsets and activation markers. METHODS: This is a prospective cohort study of 38 adults: 5 normals, 4 idiopathic urticaria, 11 IA patients in remission, 9 IA patients with acute attacks who had not yet received prednisone, and 9 IA patients who had received prednisone. The main outcome measures were lymphocyte subset and activation markers determined by two and three color flow cytometry (CD2, CD3, CD4, CD5, CD8, CD16, CD19, CD23, CD25, CD56, and HLA-DR). RESULTS: Comparing patients with acute IA with those in remission, the only significant difference was that the acute IA patients had a significantly higher percentage of CD3+HLA-DR+ cells. Normals had a significantly lower percentage of CD3+ HLA-DR+ cells than all other groups. Patients with acute IA on prednisone as well as IA patients in remission had a significantly higher percentage of CD 19+ CD23+ cells than normals. CONCLUSIONS: These results suggest that there are more activated T cells in patients with acute episodes of IA than in patients in remission. Perhaps, these activated T cells have a role in the pathogenesis of IA.

Anaphylaxis↗

PubMed2000

Human leucocyte antigens (HLA) and trimellitic anhydride (TMA) immunological lung disease.

Occupational immunological lung disease, due to low molecular weight, reactive chemicals such as trimellitic anhydride (TMA), is an emerging health problem. If there were a marker that was highly predictive of the ability of the immune system to recognize TMA as an allergen, better prevention strategies could be employed with at risk individuals. The purpose of this study is to evaluate whether human leucocyte antigen (HLA) class specificity is associated with the development of late respiratory systemic syndrome (LRSS) or asthma due to immunological sensitivity to trimellitic anhydride (TMA). This is a case control study of 17 individuals with LRSS, 12 with asthma and 22 TMA similarly exposed individuals who did not develop LRSS or asthma. Comparing the sensitized individuals (LRSS or asthma) with the non-sensitized individuals (controls), we found no difference in frequency of any HLA antigen. In summary, the lack of association of HLA antigens with LRSS or asthma due to TMA suggests that these will not be useful markers to identify at risk individuals.

Adult↗

PubMed2000

Multicenter, double-blind, placebo-controlled, multiple-challenge evaluation of reported reactions to monosodium glutamate.

BACKGROUND: The frequency of reactions reported to occur after the consumption of monosodium glutamate (MSG) is the subject of controversy. OBJECTIVE: We conducted a multicenter, multiphase, double-blind, placebo-controlled study with a crossover design to evaluate reactions reportedly caused by MSG. METHODS: In 3 of 4 protocols (A, B, and C), MSG was administered without food. A positive response was scored if the subject reported 2 or more symptoms from a list of 10 symptoms reported to occur after ingestion of MSG-containing foods within 2 hours. In protocol A 130 self-selected reportedly MSG-reactive volunteers were challenged with 5 g of MSG and with placebo on separate days (days 1 and 2). Of the 86 subjects who reacted to MSG, placebo, or both in protocol A, 69 completed protocol B to determine whether the response was consistent and dose dependent. To further examine the consistency and reproducibility of reactions to MSG, 12 of the 19 subjects who responded to 5 g of MSG but not to placebo in both protocols A and B were given, in protocol C, 2 challenges, each consisting of 5 g of MSG versus placebo. RESULTS: Of 130 subjects in protocol A, 50 (38. 5%) responded to MSG only, 17 (13.1%) responded to placebo only (P <. 05), and 19 (14.6%) responded to both. Challenge with increasing doses of MSG in protocol B was associated with increased response rates. Only half (n = 19) of 37 subjects who reacted to 5 g of MSG but not placebo in protocol A reacted similarly in protocol B, suggesting inconsistency in the response. Two of the 19 subjects responded in both challenges to MSG but not placebo in protocol C; however, their symptoms were not reproducible in protocols A through C. These 2 subjects were challenged in protocol D 3 times with placebo and 3 times with 5 g of MSG in the presence of food. Both responded to only one of the MSG challenges in protocol D. CONCLUSION: The results suggest that large doses of MSG given without food may elicit more symptoms than a placebo in individuals who believe that they react adversely to MSG. However, neither persistent nor serious effects from MSG ingestion are observed, and the responses were not consistent on retesting.

Adult↗

PubMed2000

Review of alleged reaction to monosodium glutamate and outcome of a multicenter double-blind placebo-controlled study.

Monosodium glutamate (MSG) has a long history of use in foods as a flavor enhancer. In the United States, the Food and Drug Administration has classified MSG as generally recognized as safe (GRAS). Nevertheless, there is an ongoing debate exists concerning whether MSG causes any of the alleged reactions. A complex of symptoms after ingestion of a Chinese meal was first described in 1968. MSG was suggested to trigger these symptoms, which were referred to collectively as Chinese Restaurant Syndrome. Numerous reports, most of them anecdotal, were published after the original observation. Since then, clinical studies have been performed by many groups, with varying degrees of rigor in experimental design ranging from uncontrolled open challenges to double-blind, placebo controlled (DBPC) studies. Challenges in subjects who reported adverse reactions to MSG have included relatively few subjects and have failed to show significant reactions to MSG. Results of surveys and of clinical challenges with MSG in the general population reveal no evidence of untoward effects. We recently conducted a multicenter DBPC challenge study in 130 subjects (the largest to date) to analyze the response of subjects who report symptoms from ingesting MSG. The results suggest that large doses of MSG given without food may elicit more symptoms than a placebo in individuals who believe that they react adversely to MSG. However, the frequency of the responses was low and the responses reported were inconsistent and were not reproducible. The responses were not observed when MSG was given with food.

Animals↗

PubMed1999

The signal for clathrin-mediated endocytosis of the paramyxovirus SV5 HN protein resides at the transmembrane domain-ectodomain boundary region.

The hemagglutinin-neuraminidase (HN) glycoprotein of the paramyxovirus SV5 is internalized from the cell surface via clathrin-coated pits. However, the cytoplasmic domain of SV5 HN does not contain a previously characterized internalization motif. A cell-surface-expressed chimeric protein (APK), consisting of the cytoplasmic tail, transmembrane (TM) domain, and 12 residues of the ectodomain of HN joined to the cytoplasmic protein pyruvate kinase is internalized, indicating that the N-terminal region of HN contains an internalization signal. Although SV5 HN is internalized at a rate similar to that of influenza virus hemagglutinin (HA) mutant Y543, which contains a degenerate tyrosine-based signal in its cytoplasmic tail, the elimination of the majority of the HN cytoplasmic tail, or substitution of the HN TM domain with leucine residues, did not affect the rate of HN internalization. The HN protein of the closely related virus, Newcastle disease virus (NDV), is not internalized from the cell surface. Working under the usual convention that the TM domain consists of the hydrophobic residues bounded by two charged residues, analysis of internalization of mutant and chimeric NDV HN molecules indicates that the first seven SV5 HN ectodomain residues are critical for internalization of HN. A glutamic acid residue (E37) that abuts this presumptive HN TM domain/ectodomain boundary is important for SV5 HN internalization.

Amino Acid Sequence↗

PubMed1999

Potential effect of the administration of substance P and allergen therapy on immunoglobulin E-mediated allergic reactions in human subjects.

Previously we observed and reported that immunoglobulin E-mediated (IgE-mediated) allergy in rhesus monkeys was decreased by the administration of substance P (SP) and an allergen. We extended these studies to human subjects, giving SP and 1 allergen to subjects with reactivity to more than 1 allergen, using reactivity to a second allergen as a control. SP and an allergen were initially given by aerosol delivery but subsequently were given by injection. The administration of SP and 1 allergen by aerosol delivery or injection resulted in decreased IgE-mediated reactivity to the allergen administered and also to the control allergen. This result occurred in 7 of 8 human subjects. The 2 initial subjects receiving 8 SP and allergen injections had a sharp reduction in their symptoms of ragweed hay fever lasting for 3 years to date. No significant reactions to the injection of SP occurred. Further controlled human research is necessary on the administration of SP and allergen and the mechanisms of action. Unexpected and serendipitous results first observed in rhesus monkeys and reproduced in allergic human subjects provide a new and potential mechanism for control and perhaps obliteration of common IgE-mediated allergies and even more-serious allergic problems.

Aerosols↗

PubMed1999

A clinical and immunologic study to assess risk of TMA-induced lung disease as related to exposure.

The objective of this study was to determine whether there are trimellitic anhydride (TMA) exposure levels that are very unlikely to cause immunologically mediated respiratory disease. A 3-year clinical and immunologic survey study of 286 employees was conducted at a facility that manufactures TMA. Each employee was assigned an exposure classification from 1 (highest) to 5 (lowest). Of the 28 individuals in exposure class 1, 8 (29%) developed disease; of the 57 class 2 employees, 2 (4%) developed disease; of the 79 class 3 employees, 4 (5%) developed disease. Of the 98 class 4 employees and the 24 class 5 employees, none developed disease. Inasmuch as individuals in class 4 and 5 (TMA exposure < 0.002 mg/m3) are at low risk of developing disease due to TMA, it appears that they do not warrant routine inclusion in surveillance studies.

Adult↗

PubMed1997

A functionally defined model for the M2 proton channel of influenza A virus suggests a mechanism for its ion selectivity.

The M2 protein from influenza A virus forms proton-selective channels that are essential to viral function and are the target of the drug amantadine. Cys scanning was used to generate a series of mutants with successive substitutions in the transmembrane segment of the protein, and the mutants were expressed in Xenopus laevis oocytes. The effect of the mutations on reversal potential, ion currents, and amantadine resistance were measured. Fourier analysis revealed a periodicity consistent with a four-stranded coiled coil or helical bundle. A three-dimensional model of this structure suggests a possible mechanism for the proton selectivity of the M2 channel of influenza virus.

Amino Acid Sequence↗

PubMed1996

Risk factors for immunologically mediated disease in workers with respiratory symptoms when exposed to hexahydrophthalic anhydride.

Occupational immunologic lung diseases caused by exposures to substances such as hexahydrophthalic anhydride are significant health problems. It would be useful to identify risk factors, other than exposure, for occupational immunologic lung diseases such as occupational asthma. Our objective was to identify risk factors for development of immunologically mediated disease in workers with respiratory symptoms associated with exposure to hexahydrophthalic anhydride. A medical and immunologic survey study was conducted of 33 employees with respiratory symptoms associated with hexahydrophthalic anhydride exposure. Of the 33 employees with respiratory symptoms, 20 had no immunologically mediated disease. Seven had both immunoglobulin E-mediated and immunoglobulin G-mediated disease, 5 had immunoglobulin E-mediated disease only, and 1 had immunoglobulin G-mediated disease only. Although larger samples would have rendered atopy a statistically significant risk factor (assuming effect replication), the associated effect strength represents less than a 16% improvement versus chance, which is indicative of marginal clinical significance. However, as expected, elevated levels of specific antibodies were statistically and clinically significant risk factors. Development of one type of immunologically mediated disease was highly predictive of development of the other type. In hexahydrophthalic anhydride-exposed employees with respiratory symptoms, development of immunologically mediated respiratory disease is most closely associated with presence of specific immunoglobulin E or immunoglobulin G antibodies. Neither race, age, smoking status, atopy, nor exposure levels emerged as significant risk factors in this symptomatic study population.

Adult↗

PubMed1996

Total serum IgE in trimellitic anhydride-induced asthma.

The objective of this study was to determine whether total serum IgE levels are elevated in workers with trimellitic anhydride-induced asthma as compared with anhydride-exposed workers without an occupational immunologic syndrome. Sera from 12 highly exposed workers with trimellitic anhydride-induced asthma, and from 31 similarly exposed workers without occupational immunologic disease, were assayed for total immunoglobulin E (IgE) levels by Total IgE II FAST analysis. The mean total IgE levels were 176.74 ng/mL and 34.55 ng/mL respectively. The difference between the two groups was statistically significant, but considerable overlap of IgE levels between groups was seen. In conclusion, although mean total IgE levels are significantly different between TMA-exposed workers with or without occupational asthma, the significant amount of overlap and poor sensitivity of the test preclude the use of this assay in the individual evaluation of these workers.

Adult↗

PubMed1996

Study of employees with anhydride-induced respiratory disease after removal from exposure.

The purpose of this study was to determine the clinical and immunologic status of hexahydrophthalic anhydride (HHPA)-exposed employees who had developed an immunologic respiratory disease and who have been removed from exposure for at least 1 year. In a surveillance study spanning 4 years, we identified 28 employees with HHPA-induced immunologic respiratory disease who had been removed from exposure for at least 1 year. Seven had asthma, nine had hemorrhagic rhinitis, four had both, and eight had allergic rhinitis alone. Respiratory symptoms were assessed by physician-administered questionnaires. For each employee, a physical examination, spirometry, and chest roentgenograph were performed. Antibody against HHPA conjugated to human serum albumin (HHP-HSA) was measured using an enzyme-linked immunosorbent assay. Symptoms, signs, and spirometry normalized in all but one employee. There were no chest-roentgenograph findings at follow-up that could be attributed to HHPA. There was a decline in antibody liter for both immunoglobulin E and G against HHP-HSA. In this group of 28 employees, there was only one employee with mild asthma after removal from exposure for at least I year. Although specific antibody was still present in many, the titers were generally lower at follow-up than at presentation.

Adult↗

PubMed1996

Characterization of inhibition of M2 ion channel activity by BL-1743, an inhibitor of influenza A virus.

The influenza A virus M2 integral membrane protein has ion channel activity that can be inhibited by the antiviral drug amantadine. Recently, a spirene-containing compound, BL-1743 (2-[3-azaspiro (5,5)undecanol]-2-imidazoline), that inhibits influenza virus growth was identified (S. Kurtz, G. Lao, K. M. Hahnenberger, C. Brooks, O. Gecha, K. Ingalls, K.-I. Numata, and M. Krystal, Antimicrob. Agents Chemother. 39:2204-2209, 1995). We have examined the ability of BL-1743 to inhibit the M2 ion channel when expressed in oocytes of Xenopus laevis. BL-1743 inhibition is complete as far as can be measured by electrophysiological methods and is reversible, with a reverse reaction rate constant of 4.0 x 10(-3) s(-1). In contrast, amantadine inhibition is irreversible within the time frame of the experiment. However, BL-1743 inhibition and amantadine inhibition have similar properties. The majority of isolated influenza viruses resistant to BL-1743 are also amantadine resistant. In addition, all known amino acid changes which result in amantadine resistance also confer BL-1743 resistance. However, one BL-1743-resistant virus isolated, designated M2-I35T, contained the change Ile-35-->Thr. This virus is >70-fold more resistant to BL-1743 and only 10-fold more resistant to amantadine than the wild-type virus. When the ion channel activity of M2-I35T was examined in oocytes, it was found that M2-I35T is BL-1743 resistant but is reversibly inhibited by amantadine. These findings suggest that these two drugs interact differently with the M2 protein transmembrane pore region.

Amantadine↗

PubMed1995

The paramyxovirus SV5 V protein binds two atoms of zinc and is a structural component of virions.

The paramyxovirus simian virus 5 (SV5) cysteine-rich V protein has been shown to be a virus structural protein by analysis of the polypeptides of purified SV5 virions. In addition, the V protein has been identified as a component of the virus nucleocapsid core both by the analysis of the polypeptides present in radioactively labeled preparations of purified nucleocapsids and by immunoelectron microscopy. Quantitative autoradiography was used to determine that there are approximately 350 molecules of the V protein in virions. The V protein has been purified from V recombinant baculovirus-infected insect cells and by using inductively coupled argon plasma atomic emission spectroscopy it was found that each molecule of V binds two zinc atoms.

Animals↗

PubMed1995

Study of employees with anhydride-induced respiratory disease after removal from exposure.

The purpose of this study was to determine clinical and immunologic status of hexahydrophthalic anhydride (HHPA) employees who have had immunologic respiratory disease and who have been removed from exposure for at least 1 year. In a retrospective study, 16 consecutive employees with HHPA-induced immunologic respiratory disease who had been removed from exposure for more than 1 year were evaluated. Eleven had asthma, allergic rhinitis, or both; five had hemorrhagic rhinitis. Respiratory symptoms were obtained by physician-administered questionnaire. Physical examination, spirometry, and chest film were obtained. Antibody against HHPA conjugated to human serum albumin (HHP-HSA) was determined by enzyme-linked immunosorbant assay. Symptoms, signs, and pulmonary functions were normalized in all employees. There was a decline in antibody titers for both IgE and IgG against HHP-HSA. There were no chest film findings attributable to HHPA. In this group, there appeared to be no evidence of permanent anatomic sequelae after removal from exposure for at least 1 year. Specific antibody was still present, but titers were lower at follow-up than at presentation for a substantial proportion of the sample.

Antibodies↗

PubMed1995

Analysis of the posttranslational modifications of the influenza virus M2 protein.

The sites of posttranslational modifications of the influenza A virus M2 protein were examined, and the effect of these modifications on the M2 protein ion channel activity was analyzed. Cysteine residues 17 and 19 in the M2 protein ectodomain form disulfide bonds. The cytoplasmic tail is posttranslationally modified by palmitoylation, and mutagenic studies support the view that cysteine residue 50 is the site for fatty acylation. In addition, the cytoplasmic tail of the M2 protein was found to be posttranslationally modified by the addition of phosphate to specific serine residues. Site-directed mutagenesis of serine residues in the M2 protein cytoplasmic tail, combined with phosphoamino acid analysis, indicated that serine residue 64 is the predominant site for phosphorylation but that serine residues 82, 89, and 93 were also phosphorylated but to much lesser extents. Disulfide-bond formation, palmitoylation, and phosphorylation occurred on M2 protein expressed in mammalian cells infected with influenza virus, in mammalian cells in which the M2 protein was expressed from DNA expression vectors, and when the M2 protein was expressed in oocytes of Xenopus laevis. The membrane currents of oocytes of Xenopus laevis expressing wild-type and site-specifically altered forms of the M2 protein, to ablate posttranslational modifications, indicated that none of the posttranslational modifications significantly affected the ion channel activity of the M2 protein in oocytes. Therefore, these data do not indicate a functional role for posttranslational modifications of the M2 protein in its ion channel activity.

Amino Acid Sequence↗

PubMed1995

Value of antibody level in diagnosing anhydride-induced immunologic respiratory disease.

The objective of this study was to determine whether immunologic anhydride-induced respiratory disease could be predicted on the basis of the level of specific immunoglobulin E (IgE) or immunoglobulin G (IgG) antibody. Eight-one anhydride-exposed employees in one plant were studied. Fourteen had disease and 67 did not. Immunologic studies were performed by enzyme-linked immunosorbent assay and expressed as titers. When optimal discriminant analysis was used, IgE < 1:5 and IgG < or = 1:10 were found to be the optimal titers for separating employees with and without immunologic respiratory disease caused by anhydrides. When IgG < or = 1:10 was used, 62 of 81 workers were correctly classified; the sensitivity was 100%, the positive predictive value was 45%, the specificity was 75%, and the negative predictive value was 100%. When IgE < 1:5 was used, 73 of 81 workers were correctly classified; the sensitivity was 86%, the positive predictive value was 67%, the specificity was 91%, and the negative predictive value was 97%. In conclusion, anhydride disease status can be predicted on the basis of specific IgG or IgE antibody level.

Antibodies↗

PubMed1994

Influenza virus M2 protein ion channel activity is not required to maintain the equine-1 hemagglutinin in its native form in infected cells.

The equine-1 influenza virus A/Cornell/74 (H7N7) hemagglutinin (HA) is cleaved to HA1 and HA2 in the trans Golgi network (TGN) of infected cells. The avian influenza virus A/chicken/Germany/34 (fowl plague virus Rostock) H7 HA is also cleaved to HA1 and HA2 intracellularly in the TGN. To maintain the fowl plague virus Rostock HA in its native form during transport through the TGN, a functioning M2 ion channel activity is required, otherwise the HA undergoes its transition to the low-pH form (Sugrue et al., 1990, EMBO J. 9, 3469-3476). Studies were initiated to investigate if the equine H7 HA has intracellular requirements different from those of the fowl plague virus Rostock HA. We report here that the pH of transition to the low-pH form of the equine-1 HA is approximately pH 5.3 and that the M2 protein ion channel blocker, amantadine, does not have a discernable effect on the native conformation of equine-1 HA during transport through the TGN. Moreover, the equine-1 HA expressed from cDNA does not require coexpression of a functional M2 protein to maintain HA in its native conformation.

Amantadine↗

PubMed1994

Respiratory and systemic reaction following exposure to heated electrostatic polyester paint.

A 39 year old nonatopic man developed episodes of cough, dyspnoea, sweating and shivers within 2-3 weeks of starting a new job in a factory where metallic boards were treated with an electrostatic powder paint, made of an epoxy resin and a carboxylated polyester containing polyethylene terephthalate and polybutylene terephthalate. The subject sprayed the metallic boards which were then heated in 200 degrees C ovens. The subject was first seen in an emergency room after being at work for 4 h. The physical examination revealed bilateral wheezing with fever (39 degrees C), hypoxaemia (arterial oxygen tension (PaO2) 58 torr (7.7 kPa), leucocytosis (white blood count cells.mm-3 17,000 (17 x 10(9) cells.l-1) and severe airway obstruction (forced expiratory volume in one second (FEV1)/forced vital capacity, (FVC) 1.3/2.4 l, improving to 2.2/3.8 l after bronchodilator; predicted values = 3.4/4.1 l). The subjects condition improved after being treated with oral steroids. His spirometry was normal two weeks later, although he showed mild bronchial hyperresponsiveness to methacholine with the (provocative concentration producing a 20% fall in FEV1 (PC20) being 1.7 mg.ml-1). The subject underwent specific inhalation challenges at the workplace 4 months later. After being exposed at work for 4 h, he developed a significant fall in FEV1 (-40%), fever, leucocytosis, and a fall in diffusing capacity. Lung function tests were back to normal two weeks later. Exposing the subject to heated granulated polyester for one hour in a hospital laboratory produced a fall in FEV1 of 41%, fever, leucocytosis and a fall in diffusing capacity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗