Choice of the most appropriate methods for the investigation of serum cholinesterase status.
Explore the source record for details and available documents.
Acetylcholine↗
Biomedical subjects
R T Evans
Publications and source records attributed to R T Evans.
Clustering of serum calcium and magnesium concentrations in siblings.
Concentrations of both serum calcium, adjusted for albumin, and serum magnesium of siblings from 23 families were found to cluster around different concentrations within the normal reference interval. Variation between families accounted for 37% of the total variation in calcium and 28% of that in magnesium. A disturbance of serum calcium or magnesium homeostasis in an individual resulting in an altered serum concentration that remains within the reference interval might be recognized by examining values in siblings.
Adolescent↗
Nitrogen dioxide (silo gas) poisoning in pigs.
Toxic silo gases are a potential danger to livestock housed in close proximity to silos. On the fourth day of ensiling, five fattening pigs were found dead in a pen adjoining a grass silo. Post mortem examination revealed extensive lung damage and methaemoglobinaemia. A dense reddish-brown gas was concentrated at floor level to a height of 1 m in the pen and had diffused into adjoining pens, where dry and suckling sows and litters were showing signs of respiratory distress and weakness. The gas was identified as a mixture of nitrogen dioxide and dinitrogen tetroxide. These gases may be produced in the early stages of silage making. In this case, they had accumulated in a slurry channel below the silo and leaked through an adjoining wall into the piggery. The production and toxicological effects of silo gases are discussed.
Animals↗
Estimation of the degradability of dietary protein in the sheep rumen by in vivo and in vitro procedures.
Estimates of degradability of nitrogen in the sheep rumen for a basal hay diet and for soya-bean meal (SBM), groundnut meal (GNM) and fish meal (FM), when given together with the hay, were determined from measurements of duodenal N flow, ammonia kinetics and rumen N disappearance from polyester bags and rumen outflow rate. The ability of various in vitro procedures to predict in vivo N degradability was also examined. Four sheep were given a basal hay diet (800 g dry matter (DM) and 19 g N/d) either alone or supplemented with isonitrogenous amounts (15 g N/d) of SBM, GNM or FM. Duodenal non-ammonia-N flow (g/d) was increased more by FM (8.0) than by GNM (5.9) and SBM (5.8), whilst microbial N flow (g/d) was increased more by SBM (3.9) than by GNM (2.3) and FM (1.6). N degradability values calculated from these results were 0.88, 0.76 and 0.57 for the SBM, GNM and FM respectively. The corresponding value for hay was calculated to be 0.76. The irreversible loss of ammonia in the forestomachs (g N/d) was increased more by SBM (11.9) than by GNM (7.2) and FM (5.8), whilst ammonia outflow from the rumen (g N/d) was increased to a similar extent by all supplements (1.1, 0.9 and 0.8 respectively), as was the amount of microbial N (g/d) synthesized from sources other than rumen ammonia (1.8, 2.0 and 1.9 respectively). N degradability values calculated from these results were 0.84, 0.54 and 0.45 for the SBM, GNM and FM respectively. The fractional rate of N disappearance (/h) when the feedstuffs were incubated in polyester bags in the rumen of sheep receiving the basal hay diet (800 g DM/d) was the highest for SBM (0.145) and lowest for FM (0.037), with the hay (0.082) and GNM (0.071) intermediate, whilst the fractional outflow rates from the rumen (/h) of the three supplements were similar (0.034, 0.038 and 0.030 for SBM, GNM and FM respectively). N degradability values calculated from these results were 0.82, 0.67 and 0.60 for the SBM, GNM and FM respectively; the value for the hay was 0.73. Of a number of in vitro procedures tested, only N solubility in sodium hydroxide and ammonia or total non-protein-N (NPN) production during incubation with rumen fluid in the absence of hydrazine sulphate ranked the supplements, although not the hay, in the same order as in the vivo degradability procedures.(ABSTRACT TRUNCATED AT 400 WORDS)
Ammonia↗
Properties of monoclonal antibodies to the genus-specific antigen of Chlamydia and their use for antigen detection by reverse passive haemagglutination.
The chlamydial genus-specific antigen was extracted with phenol/chloroform/petroleum ether (PCP) from preparations of Chlamydia trachomatis and C. psittaci, and quantities measured using an assay for lipopolysaccharide (LPS). The LPS from C. trachomatis contained 2.2% (w/w) of ketodeoxyoctanoic acid. Five IgG monoclonal antibodies reacted in an ELISA with LPS from both species, the antigen being periodate-sensitive and heat-resistant, confirming that all antibodies were against the genus-specific antigen. All the antibodies bound to the PCP extract of C. trachomatis on an immunoblot, at a position corresponding to the periodate-Schiff-stained bands of both C. trachomatis extract and Salmonella Re-LPS. When linked to trypsin-treated sheep erthrocytes and used in reverse passive haemagglutination tests, all antibodies gave indicator cells capable of detecting chlamydial LPS or crude preparations of chlamydiae grown in McCoy cells, the sensitivity varying with the antibody used. The antibodies varied in IgG subclass (either IgG2a or IgG3), and in ability to precipitate in immunodiffusion tests. Two antibodies cross-reacted with one strain of Acinetobacter in ELISA and with Salmonella Re-LPS in both ELISA and immunodiffusion tests. The other three did not react in ELISA with Acinetobacter strains or Salmonella Re-LPS, and none of the five reacted with LPS of E. coli or Pseudomonas morsprunorum.
Antibodies, Monoclonal↗
Susceptibility of human oral anaerobic bacteria to antibiotics suitable for topical use.
17 antibiotics, with potential for topical use, were tested for their activity against the human oral flora. Concentrations (mumol/l) required to inhibit 90% of test strains are presented and drug activities are compared. The total cultivable oral flora was susceptible to the tetracyclines including tetracycline itself, minocycline, doxycycline, and oxytetracycline and to erythromycin. On the other hand, actinobolin, kanamycin, neomycin, streptomycin, spiramycin, tyrothricin, vancomycin, clindamycin, and chloramphenicol were ineffective against many of the human oral anaerobic bacteria even at high concentration. Penicillin was effective at high concentrations but could not be recommended because organisms which are not inhibited by low concentrations are penicillinase producers. Carbenicillin was effective against all organisms except Actinobacillus actinomycetemcomitans. The gram-negative organisms involved in adult periodontitis were most susceptible to the tetracyclines, tyrothricin, carbenicillin and clindamycin, while those associated with localized juvenile periodontitis were susceptible to the tetracyclines or erythromycin. These data, combined with the previous findings that some tetracyclines exhibit marked substantivity and collagenase inhibition activity, indicate that tetracycline or minocycline are likely to be good choices in the treatment or prevention of oral diseases.
Administration, Topical↗
Rapid, reliable diagnosis of chlamydial ophthalmia by means of monoclonal antibodies.
The use of fluorescein-conjugated monoclonal antibody (Syva, UK) provided a rapid reliable diagnostic test for Chlamydia trachomatis in conjunctival samples from 100 adults with acute follicular conjunctivitis and seven babies with suspected chlamydial ophthalmia neonatorum. Elementary bodies (EBs) were seen in smears from 11 of the adults, and culture confirmed C. trachomatis infection in nine of them. Both tests were positive with specimens from four of the neonates. No specimens from either group of patients produced a negative result in the smear test but a positive result by culture. However, the two adult patients with chlamydial ophthalmia who had negative cultures but were EB-positive had both had prior topical tetracycline therapy.
Adult↗
Investigation into the value of Papanicolaou stained cervical smears for the diagnosis of chlamydial cervical infection.
Forty five (37%) of 121 female contacts of men with non-gonococcal urethritis or gonorrhoea were chlamydia positive, as judged by isolation or by detecting elementary bodies in smears with a fluorescein labelled chlamydial monoclonal antibody. Only six (13%) of these, however, had Papanicolaou stained smears in which there were inclusion like changes suggestive of chlamydial infection. Furthermore, of 15 patients who had such cytological changes, chlamydiae were detected in only six and the abnormalities were found also in Papanicolaou stained smears from 10 (13%) of the 76 chlamydia negative patients. Modifying the Papanicolaou stained smears by including endocervical material did not increase sensitivity. In addition, destaining and restaining them with the monoclonal antibody was time consuming and the results were unreliable. The staining of cervical smears with Papanicolaou reagent is a technique of low sensitivity and specificity for diagnosing or screening for chlamydial cervical infection and cannot be recommended.
Cervix Mucus↗
Unsuccessful treatment of non-gonococcal urethritis with rosoxacin provides information on the aetiology of the disease.
In a controlled trial of rosoxacin in patients with non-gonococcal urethritis (NGU), 150 mg of the antibiotic given twice daily for 10 days was compared with 300 mg triple tetracycline (Deteclo) given twice daily for the same period. Only six (19%) of 31 patients treated with rosoxacin were free of urethritis after 10 days; Chlamydia trachomatis was reisolated from 12 (92%) of 13 patients who were chlamydia positive originally, and Ureaplasma urealyticum was reisolated from 12 (80%) of 15 patients who were ureaplasma positive originally. In contrast, 18 (58%) of 31 patients treated with triple tetracycline were cured clinically after 10 days; C trachomatis was not reisolated from any of 10 patients who were chlamydia positive originally, and U urealyticum was reisolated from only three (17%) of 18 patients who were ureaplasma positive originally. These results were consistent with the antimicrobial inactivity of rosoxacin in vitro and they cannot be reconciled with previous reports of successful use of this antibiotic in NGU. Ureaplasmas were isolated more frequently and in larger numbers from chlamydia negative than from chlamydia positive patients, but it is probable that ureaplasmas resistant to tetracycline were not responsible for persistent urethritis.
4-Quinolones↗
Antibiotic susceptibility of anaerobic bacteria from the human oral cavity.
Anaerobic, agar-dilution, minimal inhibitory concentrations (MICs) of 18 antibiotics are given for the numerically important bacterial groups from the human oral cavity. Strains are divided into susceptibility categories using the guidelines for interpretation of MICs suggested by the National Committee for Clinical Laboratory Standards. These guidelines are based on data on antibiotic concentrations attainable in serum following various dosage regimens. MICs are also compared with attainable gingival fluid levels where these are known. The highest percentages of strains were susceptible to tetracycline, with 89% of the 139 strains tested susceptible to serum levels and 97% conditionally susceptible to attainable gingival fluid levels. Ninety-eight percent of strains were conditionally susceptible to attainable gingival fluid levels of minocycline, but many strains, including Actinobacillus actinomycetemcomitans, were only moderately susceptible to attainable serum levels of this tetracycline analogue. Carbenicillin was effective against most groups of organisms, with the important exception of A. actinomycetemcomitans, at serum levels attainable with oral formulations of carbenicillin. Only 2% of the total strains tested were resistant to penicillin, while 33% of strains were categorized as moderately susceptible. Clindamycin was active against many strains of Gram-negative bacteria but was not active against A. actinomycetemcomitans, some Bacteroides, Eikenella corrodens, or the anaerobic vibrios. Metronidazole was active against A. actinomycetemcomitans, all five groups of oral Bacteroides tested, and against Capnocytophaga species. Chloramphenicol was active against A. actinomycetemcomitans, but not against most of the other groups of oral organisms. Nearly all groups contained strains non-susceptible to serum levels attainable with the usual doses of erythromycin, spiramycin, vancomycin, kanamycin, neomycin, streptomycin, doxycycline, oxytetracycline, or chlortetracycline; several strains were resistant to maximum attainable serum levels of each of these antibiotics except doxycycline.
Actinobacillus↗
The combined effects of pregnancy and repeated plasma exchange on serum cholinesterase activity.
Fourteen patients are described in whom repeated plasma exchange was performed as part of their treatment for Rh alloimmunisation during pregnancy. Despite administration of fresh frozen plasma at frequent intervals during therapy, serum cholinesterase activity was shown to be reduced to levels sufficient to put many of them at risk from suxamethonium sensitivity. It is recommended that if short-acting muscle relaxants are intended to be used during the delivery of such patients, a careful investigation of cholinesterase status should be undertaken beforehand.
Anesthesia, Obstetrical↗
Sensitivity of detecting Chlamydia trachomatis elementary bodies in smears by use of a fluorescein labelled monoclonal antibody: comparison with conventional chlamydial isolation.
Commercially produced fluorescein labelled monoclonal antibodies for the detection of Chlamydia trachomatis have recently become available. One is for detecting inclusions in cell culture (culture confirmation) and the other for detecting elementary bodies in smears from potentially infected sites. We have compared the two monoclonal antibodies with our routine isolation method, which utilises Giemsa staining of cycloheximide treated McCoy cell cultures. The culture confirmation system offered no advantages over Giemsa staining for the detection of inclusions in cell monolayers. By contrast, using monoclonal antibody to detect elementary bodies in smears was much quicker and simpler and slightly more sensitive than isolation of chlamydiae in cell culture. For specimens from seven babies with conjunctivitis and from 35 female contacts of men with non-gonococcal urethritis, there was complete agreement between the results of detecting inclusions in culture and those of seeking elementary bodies in smears. For samples from 100 men with non-gonococcal urethritis and from 100 men with gonorrhoea there was 99% and 94% agreement, respectively, between the results of the two tests. Other aspects and possible uses of the new detection system are discussed.
Antibodies, Monoclonal↗
On the identification and frequency of the J and K cholinesterase phenotypes in a Caucasian population.
An analysis of investigations performed between December 1978 and September 1982 into the cholinesterase status of 795 Caucasian patients has revealed an E1aE1j genotype in three (0.4%) and an E1aE1k genotype in 22 (2.8%). Both groups of patients are at increased risk of sensitivity to suxamethonium. Inhibitor numbers characteristic of these genotypes are reported which it is hoped will assist other workers to identify them more easily. While the J allele is probably rare among the general population it is suggested that as many as one person in 76 could be a KK homozygote. Our findings provide a possible explanation of the low cholinesterase activities seen in some patients for which there is no other obvious cause.
Cholinesterase Inhibitors↗
Effect of adjuvants on orally administered antigens.
Explore the source record for details and available documents.
Acetylmuramyl-Alanyl-Isoglutamine↗
Detection of chlamydiae by isolation and direct examination.
Explore the source record for details and available documents.
Bacteriological Techniques↗
Studies of body temperatures, blood lactate, cortisol and free fatty acid levels during exercise in human subjects susceptible to malignant hyperpyrexia.
Body temperature at a variety of sites (external auditory meatus, rectum, thigh, chest wall, pad of thumb), blood cortisol, lactate and free fatty acid levels and urinary adrenaline, noradrenaline and dopamine excretion were measured in five human subjects susceptible to malignant hyperpyrexia (MHS) and five normal subjects during a period of progressively severe exercise, starting at rest and going up to an exercise intensity producing heart rates in excess of 180 beats/min. In addition, results are reported of a further study of rectal temperature measurements made during a period of mild exercise in a different group of nine MH susceptible and nine nonsusceptible subjects. The results of the progressive exercise study indicated that as the exercise increased in severity, central (external auditory meatal) temperature rose more in the MHS subjects than it did in the controls. Thumb temperature in both groups rose with exercise but in the MHS subjects this rise was significantly delayed compared with the control subjects. It was thought that this was due to a delay in the onset of vasodilatation which usually accompanies high intensities of exercise. Serum free fatty acids and cortisol levels rose more in the MHS subjects than the controls and during the early stages of exercise blood lactate concentrations in the MHS subjects were higher than in the controls group. During mild exercise, rectal temperature in the MHS subjects was lower than in the controls. It was concluded that the pattern of temperature change was evidence of an abnormality of the heat dissipation mechanisms in the MHS subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Minimal inhibitory concentrations of various antimicrobial agents for human oral anaerobic bacteria.
The minimal inhibitory concentrations of a series of antimicrobial agents for human oral organisms were determined under anaerobic growth conditions by an agar dilution assay. With the exception of black-pigmented Bacteroides spp., minimal inhibitory concentrations for oral isolates were similar to those for non-oral isolates of organisms of the same or closely related species.
Anti-Bacterial Agents↗
Tetracycline and its derivatives strongly bind to and are released from the tooth surface in active form.
Several antibiotics were found to adsorb to saliva-coated enamel and to inhibit in vitro plaque formation by pure cultures of oral bacteria: Actinomyces viscosus, Actinomyces naeslundii and Streptococcus mutans. Tetracycline, minocycline and oxytetracycline adsorbed to the greatest degree, showing 100-fold higher adsorption than spiramycin, the test antibiotics with least adsorption. Inhibition of in vitro plaque formation was found to require both drug substantivity (capacity for adsorption) and antimicrobial activity. Inhibition of plaque formation in the in vitro assay employed correlated well with clinical efficacy.
Actinomyces↗