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Biomedical subjects

M E Ward

Publications and source records attributed to M E Ward.

At least 127 records · Page 7Linked to original sources
PubMed1988

High-level expression and epitope localization of the major outer membrane protein of Chlamydia trachomatis serovar L1.

Fragments of the gene encoding the major outer membrane porin protein (MOMP) of Chlamydia trachomatis serovar L1 were ligated into the pUC plasmid vectors to give a series of overlapping recombinants expressing MOMP from the lac promoter. Induction of this promoter with IPTG leads to high-level expression of the recombinant porin protein. Electron microscopy shows the presence of insoluble inclusions within the Escherichia coli host cells. Probing the expressed MOMP fragments with a set of monoclonal antibodies permitted localization of the four binding sites (epitopes) of primary-sequence-dependent monoclonal antibodies that exhibit genus-, species-, subspecies- and type (serovar)-specific reactivities.

Antibodies, Monoclonal↗
PubMed1988

Gonococcal and chlamydial antibodies in ectopic and intrauterine pregnancy.

Sera from 50 women with ectopic pregnancy and 50 age-matched control women with intrauterine pregnancy were tested by enzyme-linked immunosorbent assay (ELISA) using C. trachomatis and N. gonorrhoeae pili as antigens. In the ectopic pregnancy group 76% had IgG antibodies to C. trachomatis compared with 38% in the controls. The prevalence of gonococcal IgG antibody was 32% in the ectopic pregnancy group and 4% in the controls. The prevalences of IgA antibodies to the two organisms ranged from 2 to 12% and were similar in the two groups; cultures for C. trachomatis from cervical swabs from the ectopic pregnancy group were negative. Chlamydial antigen was detected (by ELISA) in exfoliated cervical cells of only one patient in this group.

Antibodies, Bacterial↗
PubMed1988

Respiratory sensation and pattern of respiratory muscle activation during diaphragm fatigue.

We have examined the relationship between respiratory effort sensation (modified Borg scale) and amplitude of the integrated surface electromyogram of the diaphragm (Edi, esophageal electrode), rib cage muscles (Erc), and sternomastoid muscle (Esm) during the development of diaphragm fatigue in five normal subjects. Three conditions were studied: run A: transdiaphragmatic pressure (Pdi), 65% Pdimax; esophageal pressure (Pes), 60% Pesmax; run B: Pdi, 50% Pdimax; Pes, 60% Pesmax; and run C: Pdi, 50% Pdimax; Pes, 20% Pesmax. During all runs there was a progressive rise in sensation, which was greater in runs A and B than in run C (P less than 0.05, analysis of variance). There was no difference between runs A and B. At the end of run C subjects did not report a maximal Borg score despite their inability to generate the target Pdi. The increase in sensory score with fatigue correlated highly with Esm/Esmmax and with Erc/Ercmax. There was no correlation between sensory score and Edi/Edimax. We conclude that the increase in respiratory effort sensation that accompanies diaphragm fatigue is not due to perception of increased diaphragmatic activation. It may reflect increased overall respiratory motor output not directed to the diaphragm.

Adult↗
PubMed1987

Detection of Chlamydia trachomatis by enzyme immunoassay in patients with trachoma.

Trachoma control necessitates identification of individuals shedding ocular chlamydiae. Conventional techniques of chlamydial culture are unsuitable for large field surveys in developing countries. In this study an enzyme immunoassay (EIA) developed for the detection of chlamydial antigen in genital-tract infection was used in trachoma. Conjunctival swabs were taken for chlamydial antigen detection from 1225 subjects in a Gambian village with endemic trachoma. Of these, 997 had insignificant or no disease and 172 had mild, 30 moderate, and 26 severe disease. Chlamydial antigen was detected in 5.0%, 20.3%, 46.7%, and 26.9% of subjects in these four categories, respectively. Samples for chlamydial isolation were obtained from 259 subjects. The corresponding rates of detection obtained by chlamydial isolation were 3/90 (3.3%), 16/129 (12.4%), 7/21 (33.3%), and 7/19 (36.8%). If isolation is taken as the "gold standard", the EIA technique had a sensitivity of 70.6% and a specificity of 90%. A substantial proportion of subjects with severe conjunctival scarring, from whom chlamydiae cannot generally be isolated, were antigen positive by EIA, implying that persistent chlamydial antigen plays a part in the pathogenesis of the late sequelae of trachoma.

Antigens, Bacterial↗
PubMed1987

Chlamydial and gonococcal antibodies in sera of infertile women with tubal obstruction.

Sera from 48 infertile women with tubal pathology and from 77 infertile women with normal fallopian tubes were tested by enzyme linked immunosorbent assay (ELISA) using Chlamydia trachomatis and Neisseria gonorrhoeae antigens. Control sera were obtained from women undergoing abortion, sterilisation, and from women practising barrier contraception. The results of ELISA for antibodies to chlamydiae were in close agreement with results published previously of an immunofluorescence test on these sera. Antibodies to C trachomatis were found in 73% of the infertile women with tubal pathology, significantly more than in any of the control groups. Only a very low prevalence (2-5%) of antibodies to gonococcal pili was found in all groups, except women undergoing abortion (16%).

Adult↗
PubMed1986

Antigenic specificity of human antibody to chlamydia in trachoma and lymphogranuloma venereum.

An understanding of the molecular basis of the humoral immune response to chlamydial infections in man requires the identification of target antigens to which antibodies are directed. The antigenic specificity of antibody from patients with lymphogranuloma venereum (LGV) or trachoma was therefore assessed by Western blotting. Surface polypeptides were first identified using purified chlamydial outer membrane complex as antigen. Antibodies in sera from patients with LGV but not from control negative sera reacted with a wide range of chlamydial surface polypeptides with molecular masses of 19, 29, 41, 58, 63 and 65 kDa. The major component of the antibody response detected by both immunoblotting and immunoprecipitation assay was directed against the major outer membrane protein (MOMP). Antibody to MOMP was species-specific on Western blotting, whereas antibody to several other polypeptides recognized common immunodeterminants on polypeptides of C. psittaci Cal-10 of equivalent molecular mass. Immunologically C. psittaci Cal-10 was more closely related to LGV strains of C. trachomatis than a guinea pig inclusion conjunctivitis strain of C. psittaci. Trachoma sera collected from a village in southern Iran showed predominantly type-specific antibody on micro-immunofluorescence to serotype A or B trachoma agents. These sera showed a weak immune response to MOMP, a pronounced response to a polypeptide of 36 kDa and much less widespread reactivity with other chlamydial polypeptides. The lack of an immune response to SDS-stable immunodeterminants on MOMP might contribute to the susceptibility of trachoma patients to repeated cycles of ocular infection with chlamydiae.

Antibodies↗
PubMed1986

Fire in the operating theatre. Evacuation pre-planning may save lives.

An operating theatre fire and the steps taken to deal with it are described; the difficulties encountered in evacuating anaesthetised patients are highlighted. Measures which might be taken to prevent recurrence of these problems, and recommendations on the institution of fire drills for the safety of patients and staff are given.

Disaster Planning↗
PubMed1985

Effect of chronic lung disease on the perception of added inspiratory loads.

The perceived magnitude of externally added loads to breathing was estimated in 10 normal subjects and 10 patients with chronic lung disease (5 obstructive, 5 interstitial disorders) to determine if chronic mechanical abnormalities of the respiratory system are accompanied by changes in the perception of dyspnea. Flow rates and tidal volumes were varied to assess the effect of altered patterns of breathing. With added resistive loads, the perceived magnitude increased as both resistance and the flow rate increased. With elastic loads the perceived magnitude increased as both elastance and tidal volume increased. In all subjects, perceived magnitude of added loads was most directly related to the inspiratory pressure used to overcome the load. Although the exponent for the power function relationship between perceived magnitude and the physical magnitude of the load was affected by the subject's age, there was no difference between the patients studied and the age-matched normal subjects. The results indicate that the sensation associated with added loads to breathing is the same in patients with chronic lung disease as in normal subjects. Also, they suggest that the altered pattern of breathing in patients with chronic lung disease is a behavioral adaptation to minimize respiratory distress.

Adult↗
PubMed1985

Celiac disease and spinocerebellar degeneration with normal vitamin E status.

We studied a 47-year-old man with spinocerebellar degeneration and malabsorption due to celiac enteropathy; the serum vitamin E level was normal. The neurologic disorder initially deteriorated despite improvement of small bowel histology on a gluten-free diet and vitamin E therapy, but later stabilized. The etiology of the neurologic disorder in adult celiac disease has not been identified and does not appear to be vitamin E deficiency.

Celiac Disease↗
PubMed1985

Simple mastectomy under local anaesthesia.

Nine patients with locally advanced carcinoma of the breast underwent simple mastectomy under regional anaesthesia (1% lignocaine and 1:100,000 adrenaline). Preoperative sedation was provided by oral lorazepam. There were no technical problems, evidence of lignocaine toxicity or excessive operative blood loss and no wounds became infected.

Aged↗
PubMed1984

Control mechanisms governing the infectivity of Chlamydia trachomatis for HeLa cells: the role of calmodulin.

Adhesion of the obligate intracellular bacterium Chlamydia trachomatis to host cells is associated with a flux of Ca2+ across the cell membrane, and infection is enhanced by treatment of host cells with Ca2+ ionophore. The possibility that Ca2+ might interact with host cell Ca2+ regulatory proteins to promote chlamydial infection was investigated. Treatment of HeLa 229 cells with the calmodulin inhibitors pimozide, trifluoperazine, chlorpromazine, promethazine or haloperidol reduced chlamydial infectivity as measured by inclusion counting or the specific incorporation of [3H]threonine. The inhibitory effect was reversible, dose-related and shown to be associated with impairment of chlamydial adhesion and uptake by the host cells. This effect was clearly distinguished from the delayed maturation of chlamydiae due to continuous exposure to calmodulin inhibitors which may result from a decrease in the availability of high energy compounds from the host cells necessary for chlamydial growth. The possible mechanisms for calmodulin-mediated chlamydial endocytosis are discussed.

Adhesiveness↗
PubMed1984

Control mechanisms governing the infectivity of Chlamydia trachomatis for HeLa cells: mechanisms of endocytosis.

The mechanism by which Chlamydia trachomatis is endocytosed by host cells is unclear. Studies of the kinetics of chlamydial attachment and uptake in the susceptible HeLa 229 cell line showed that chlamydial endocytosis was rapid and saturable but limited by the slow rate of chlamydial attachment. To overcome this limitation and to investigate the mechanism of endocytosis, chlamydiae were centrifuged onto the host cell surface in the cold to promote attachment. Endocytosis of the adherent chlamydiae was initiated synchronously by rapid warming to 36 degrees C. Electron micrographs of chlamydial uptake 5 min after onset showed that chlamydial ingestion involves movement of the host cell membrane, leading to interiorization in tight, endocytic vacuoles which were not clathrin coated. Chlamydial ingestion was not inhibited by monodansylcadaverine or amantadine, inhibitors of receptor-mediated endocytosis and chlamydiae failed to displace [3H]sucrose from micropinocytic vesicles. Chlamydial endocytosis was markedly inhibited by cytochalasin D, an inhibitor of host cell microfilament function, and by vincristine or vinblastine, inhibitors of host cell microtubules. Hyperimmune rabbit antibody prevented the ingestion of adherent chlamydiae, suggesting that endocytosis requires the circumferential binding of chlamydial and host cell surface ligands. These findings were incompatible with the suggestion that chlamydiae enter cells by taking advantage of the classic mechanism of receptor-mediated endocytosis into clathrin-coated vesicles, used by the host cell for the internalization of beta-lipoprotein and other macromolecules, but were consistent with the hypothesis that chlamydiae enter cells by a microfilament-dependent zipper mechanism.

Cadaverine↗
PubMed1984

Respiratory obstruction following vocal cord injection of Teflon paste.

Injection of poly(tetrafluoroethylene) past (Teflon) into vocal cords is becoming more common, but immediate morbidity has not previously been described. A case is reported in which acute airway obstruction followed the injection of Teflon paste into a paralysed vocal cord. This was easily managed, without resort to tracheostomy, by topical lignocaine which reduced the overactivity of the normal vocal cord.

Acute Disease↗