Biomedical subjects

R London

Publications and source records attributed to R London.

75 records · Page 5Linked to original sources

PubMedDate not supplied

Prognostic factors for persons with idiopathic chronic fatigue.

BACKGROUND: The simultaneous examination of a large number of patient characteristics in a prospective study of patients with chronic fatigue. OBJECTIVE: To compare the relative importance of these characteristics as prognostic factors. METHODS: The data analyzed were from 199 subjects in a registry of persons who were aged 18 years or older and had idiopathic fatigue for at least 6 months. All subjects completed an extensive baseline questionnaire that provided information about fatigue, demographic characteristics, medical conditions, lifestyle, sleeping habits, psychological characteristics, and the presence of criteria for chronic fatigue syndrome. Changes in fatigue severity from baseline to 2-year follow-up were tested for an association with risk factors at baseline and with changes in symptoms other than fatigue during the follow-up period. RESULTS: The following characteristics at baseline significantly and independently predicted greater fatigue improvement: less unclear thinking, fewer somatoform symptoms not used to define chronic fatigue syndrome, infrequent awakening, fewer hours sleeping, and being married. Of 29 subjects who at baseline reported no somatoform symptoms unrelated to chronic fatigue syndrome and who thought clearly most of the time, 8 substantially improved, compared with 1 of 29 subjects who had more than 2 somatoform symptoms and never thought clearly (P = .01). Improvements in the following symptoms were significantly and independently associated with improvements in fatigue: unclear thinking, depression, muscle aches, and trouble falling asleep. CONCLUSIONS: This study identified characteristics of subjects that seem to be of prognostic importance for idiopathic chronic fatigue. Symptoms that change concomitantly with changes in fatigue may be intrinsically linked to fatigue.

Adolescent↗

PubMedDate not supplied

Quinone methide formation from para isomers of methylphenol (cresol), ethylphenol, and isopropylphenol: relationship to toxicity.

The oxidative metabolism and toxicity of the para isomers of methylphenol (cresol), ethylphenol, and isopropylphenol were studied using male Sprague-Dawley rat liver microsomes and precision-cut liver slices. Reactive intermediates from each compound were trapped using radiolabeled glutathione and were detected and quantified by HPLC. Conjugates were collected and their structures determined by fast atom bombardment mass spectrometry and proton nuclear magnetic resonance. During microsomal incubations each test compound formed monoglutathione conjugates with structures which are consistent with the formation of quinone methide intermediates. In each case the glutathione moiety was attached to the benzylic carbon on the alkyl side chain of the phenol. With ethylphenol, which has a prochiral benzylic carbon, two isomeric conjugates were detected. The rate of formation of the glutathione conjugates in liver slice incubations was 4-isopropylphenol > 4-ethylphenol > 4-methylphenol. This correlated with the toxicity of the three compounds in liver slices. At equimolar concentrations 4-isopropylphenol was the most toxic while 4-methylphenol was the least toxic. Depletion of intracellular glutathione was observed in the presence of each test compound which preceded cell death. Enhancement of cellular thiol levels with N-acetylcysteine protected cells from the toxic effects of all three compounds as did inhibition of cytochrome P450 activity with metyrapone. These results suggest the formation of quinone methide intermediates from three alkylphenols during oxidative metabolism and demonstrate a correlation between the amount of reactive intermediate formed and toxicity observed in liver slices.

Animals↗

PubMedDate not supplied

Acute hemorrhagic cystitis due to Escherichia coli.

Acute hemorrhagic cystitis in children has been associated with adenovirus type 11 infection as well as with urinary tract infection due to Escherichia coli. In the United States, the incidence of hemorrhagic cystitis due to E. coli appears to be as high as, or higher than that due to adenovirus type 11, but few studies are available. We studied 14 episodes of acute hemorrhagic cystitis in 13 children aged 2-14 years (mean 6.2). Ten were female. Gross hematuria lasted 1-9 days (mean 2.2). Urine cultures were positive (greater than 10(5) colonies/ml) in 6 episodes (43%). One additional patient had a suspected infection. All children grew E. coli. Pyuria was present in 78.5% but did not correlate with positive cultures. IVP was normal in 82%. E. coli appears to be a much more common cause of acute hemorrhagic cystitis in children than heretofore reported.

Acute Disease↗