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M Logan

Publications and source records attributed to M Logan.

At least 37 records · Page 2Linked to original sources

Degradation of halogenated aliphatic compounds by the ammonia- oxidizing bacterium Nitrosomonas europaea.

Suspensions of Nitrosomonas europaea catalyzed the ammonia-stimulated aerobic transformation of the halogenated aliphatic compounds dichloromethane, dibromomethane, trichloromethane (chloroform), bromoethane, 1,2-dibromoethane (ethylene dibromide), 1,1,2-trichloroethane, 1,1,1-trichloroethane, monochloroethylene (vinyl chloride), gem-dichloroethylene, cis- and trans-dichloroethylene, cis-dibromoethylene, trichloroethylene, and 1,2,3-trichloropropane, Tetrachloromethane (carbon tetrachloride), tetrachloroethylene (perchloroethylene), and trans-dibromoethylene were not degraded.

Ammonia

The management of hydrothorax in continuous ambulatory peritoneal dialysis (CAPD).

Four patients on continuous ambulatory peritoneal dialysis (CAPD) developed large, symptomatic pleural effusions after commencing peritoneal dialysis. Pleuroperitoneal fistula in each case was diagnosed by the presence of a high glucose content in pleural fluid, with a normal corresponding blood sugar, and was confirmed by isotope or contrast peritoneography. Two patients had their effusions drained percutaneously, and then underwent pleural sclerosis with intracavitary tetracycline. Two patients had a thoracotomy performed, of which no fistula was identified in one case, and the other patient underwent pleurectomy. All four patients successfully recommenced CAPD several weeks after therapy, without recurrence of effusions. We conclude that pleuroperitoneal connections associated with CAPD do not mandate cessation of peritoneal dialysis and conversion to maintenance haemodialysis. Definitive diagnosis requires aspiration of pleural effusions for glucose estimation. Contrast or isotopic peritoneography is helpful in localising the fistula, but in our experience did not alter management. Simple sclerotherapy is effective and avoids the need for a formal thoracotomy.

Aged

Degradation of trichloroethylene by the ammonia-oxidizing bacterium Nitrosomonas europaea.

Suspensions of Nitrosomonas europaea are shown to cause the complete disappearance of 10 microM trichloroethylene at rates of 1 microM mg protein-1. The reaction continues at nearly this rate for many hours. Fresh cells catalyze the reaction in the absence of added ammonium (presumably utilizing endogenous ammonia or stored reductant). In older cells, trichloroethylene degradation depends on the addition of ammonia. Acetylene, 2-chloro 6-trichloromethylpyridine and alpha alpha'dipyridyl, which inhibit the oxidation of ammonia by cells, inhibit the degradation of trichloroethylene. Thus degradation of trichloroethylene is dependent on- and possibly catalyzed by the ammonia oxidizing enzyme.

Ammonia

A simulated "acquired" imperforate hymen following the genital trauma of sexual abuse.

Imperforate hymen, a condition in which the hymen has no aperture, usually occurs congenitally, secondary to failure of development of a lumen. A case of a documented simulated "acquired" imperforate hymen is presented in this article. The patient, a 5-year-old girl, was the victim of sexual abuse. Initial examination showed tears, scars, and distortion of the hymen, laceration of the perineal body, and loss of normal anal tone. Follow-up evaluations over the next year showed progressive healing. By 7 months after the injury, the hymen was replaced by a thick, opaque scar with no orifice. Patients with an apparent imperforate hymen require a sensitive interview and careful visual inspection of the genital and anal areas to delineate signs of injury. The finding of an apparent imperforate hymen on physical examination does not eliminate the possibility of antecedent vaginal penetration and sexual abuse.

Anus Diseases

HR 756, a highly active cephalosporin: comparison with cefazolin and carbenicillin.

HR 756, a new parenteral cephalosporin, was compared with cefazolin and carbenicillin for activity against a total of 264 strains of Pseudomonas aeruginosa, Escherichia coli, Klebsiella spp., Proteus mirabilis, Proteus spp. (indole positive), Enterobacter spp., Salmonella typhi, Serratia marcescens, Providencia stuartii, and Staphylococcus aureus. In every comparison, except that with the last organism, HR 756 was clearly more active than cefazolin and carbenicillin. All three compounds had similar activity against penicillin-susceptible staphylococci; against penicillin-resistant strains, HR 756 and cefazolin were equally active and superior to carbenicillin. HR 756 was compared with penicillin for activity against strains of Streptococcus pyogenes, Lancefield group D streptococci, and Neisseria gonorrhoeae; with ampicillin against Haemophilus influenzae; and with cefoxitin against Bacteriodes fragilis. HR 756 was clearly more active than the respective reference compounds in all of these comparisons, except those involving the streptococci. HR 756 and penicillin were essentially equally active against S. pyogenes; against Lancefield group D, penicillin was 32 times as active as HR 756. HR 756 not only compared favorably with the reference compounds with respect to relative activity, but also effected growth inhibition of essentially all test organisms (P. aeruginosa and group D streptococci excepted) at remarkably low concentrations ranging from 0.015 to 2.0 mug/ml. A series of seven transfers of selected strains of E. coli, Klebsiella spp., S. aureus, and P. aeruginosa through medium containing HR 756 led to emergence of strains with significant levels of resistance to the agent. Resistance to HR 756 was retained for at least seven transfers through plain medium.

Bacteria

The origin and behavior of two isodicentric bisatellited chromosomes.

Karyotyping revealed three cell lines in a boy with mental retardation and few other abnormalities. Thirty cells exhibited a normal karyotype, and 54 had an extra acrocentric chromosome of E group size with satellites on the long and short arms. The remaining 20 cells each had, in addition to the first marker (M1), a second tiny bisatellited chromosome (M2). C-banding demonstrated that both markers were dicentric. G-, C-, and Q-banding and satellite association data were consistent with the markers having originated from chromosome 15 material. We propose that M1 was formed from a meiotic breakage and a chromatid fusion in the proximal long arms of an acrocentric pair. This would have produced a symmetrical isodicentric chromosomes, plus one or two acentric fragments. M2 then could have resulted from a dicentric bridge-break-synthesis-reunion phenomenon. This model of abnormal meiotic exchange can be generalized to encompass the formation of other dicentric isochromosome cases of isochromosome X.

Azure Stains

Medical history.

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Dental Records