Biomedical subjects

P F Russell

Publications and source records attributed to P F Russell.

8 recordsLinked to original sources

PubMed1994

In vitro antiplasmodial, antiamoebic, and cytotoxic activities of a series of bisbenzylisoquinoline alkaloids.

Twenty-four bisbenzylisoquinoline alkaloids were screened for antiplasmoidal, antiamoebic, and cytotoxic activities by use of in vitro microtests. Eight of the alkaloids had antiplasmodial activity, with a 50% inhibitory concentration (IC50) of less than 1 microM against a multidrug-resistant strain of Plasmodium falciparum (chloroquine had an IC50 of 0.2 microM). The three alkaloids most active against Entamoeba histolytica, aromoline, isotrilobine, and insularine, had IC50s of 5 to 11.1 microM (metronidazole had an IC50 of 1.87 microM). None of the 24 bisbenzylisoquinoline alkaloids exhibited significant cytotoxicity against the KB cell line, the most toxic being berbamine, with an IC50 of 17.8 microM (the IC50 of podophyllotoxin was 0.008 microM). Bisbenzylisoquinoline alkaloids merit further investigation as potential novel antimalarial agents.

Alkaloids↗

PubMed1991

Plasmodium falciparum: effects of phaeanthine, a naturally-occurring bisbenzylisoquinoline alkaloid, on chloroquine-resistant and -sensitive parasites in vitro, and its influence on chloroquine activity.

Phaeanthine, a bisbenzylisoquinoline alkaloid which occurs naturally in Triclisia species, was extracted from Triclisia patens (Menispermaceae) obtained from Sierra Leone (West Africa). In vitro, phaeanthine was found to be twice as potent against a chloroquine-resistant Plasmodium falciparum strain (K1), as against a chloroquine-sensitive clone (T9-96), with 50% inhibitory concentrations of 365.85 (+/- 11.41) nM and 704.87 (+/- 81.48) nM respectively. At a sub-inhibitory concentration of 80.35 nM, chloroquine resistance was not reversed by phaeanthine. Isobolograms constructed from experiments with chloroquine/phaeanthine combinations showed antagonism in T9-96 and an additive effect in K1. In a 48-hour microtest, phaeanthine at antimalarial concentrations showed no cytotoxicity to mammalian (KB) cells in vitro.

Animals↗

PubMed1980

British Regional Heart Study: geographic variations in cardiovascular mortality, and the role of water quality.

In a study of regional variations in cardiovascular mortality in Great Britain during 1969-73 based on 253 towns the possible contributions of drinking water quality, climate, air pollution, blood groups, and socioeconomic factors were evaluated. A twofold range in mortality from stroke and ischaemic heart disease was apparent, the highest mortality being in the west of Scotland and the lowest in south-east England. A multifactorial approach identified five principal factors that substantially explained this geographic variation in cardiovascular mortality-namely, water hardness, rainfall, temperature, and two social factors (percentage of manual workers and car ownership). After adjustment for other factors cardiovascular mortality in areas with very soft water, around 0.25 mmol/l (calcium carbonate equivalent 25 mg/l), was estimated to be 10-15% higher than that in areas with medium-hard water, around 1.7 mmol/l (170 mg/l), while any further increase in hardness beyond 1.7 mmol/l did not additionally lower cardiovascular mortality.Thus a negative relation existed between water hardness and cardiovascular mortality, although climate and socioeconomic conditions also appeared to be important influences. Cross-sectional and prospective surveys of 7500 middle-aged men from 24 towns are in progress and will permit further exploration of these geographic differences, especially with regard to personal risk factors such as blood pressure, blood lipid concentrations, and cigarette smoking.

Adult↗

PubMed1977