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Biomedical subjects

G R Jones

Publications and source records attributed to G R Jones.

At least 145 records · Page 8Linked to original sources
PubMed1980

Early cutback in chemical energy production if the Crocker sarcoma (S180) undergoing haemorrhagic necrosis as a result of endotoxin administration.

Alterations in the tumor adenine nucleotide pattern (TANP) have been measured at various times in a solid murine tumor undergoing haemorrhagic necrosis in vivo as a consequence of endotoxin administration. The ATP level fell rapidly in the first few hours; the AMP content initially rose, but began to fall back at 4 h. Overall adenine nucleotide losses occurred promptly, with only 4% of the original amount remaining at 24 h. Levels of glucose, glucose 6-phosphate, pyruvate, and lactate were also measured, and, with the exception of lactate, were for the most part lower in tumors from endotoxin-treated animals. Only minor alterations in the adenine nucleotide pattern were seen after either 4 or 24 h in the livers of normal or tumor-bearing mice in response to endotoxon injection, even when the creatures were moribund. The changes reported in the tumor are believed to have arisen not as a result of capillary stasis, but from prompt and selective disturbances to mitochondrial function in the tumor which have been described previously (Jones, 1977b, 1979).

Adenine Nucleotides↗
PubMed1980

The effect of oxprenolol, acebutolol and propranolol on thyroid hormones in hyperthyroid subjects.

Serum thyroid hormone levels were measured before and during 10 days treatment with acebutolol (400 mg/day), oxprenolol (160 mg/day) and propranolol (160 mg/day) eighteen hyperthyroid patients. A significant change in thyroid hormone concentrations was seen only in the group treated with propranolol. Propranolol should be used in preference to beta-adrenoreceptor blocking drugs with partial agonist activity, in the treatment of hyperthyroidism.

Acebutolol↗
PubMed1979

Early mitochondrial damage in the induction of haemorrhagic necrosis in the Crocker sarcoma (S 180) by endotoxin.

Disturbances in the functional properties of tumor mitochondria have been studied during the course of induction of haemorrhage brought about by endotoxin in the murine Crocker sarcoma (S 180). Extensive impairment of function was already present in mitochondria isolated from control tumors, as shown by low respiratory control ratios. The existing mitochondrial damage intensified promptly in response to injection of endotoxin long before the onset of haemorrhage at 4 h. The nature of the additional damage took two forms, depending on the duration of exposure to endotoxin; first, at 30 min, a true uncoupling of oxidative phosphorylation was seen, largely reversible in vitro by pre-treatment of the isolated organelles with bovine serum albumin (BSA). Second, at 1 h and later, oxygen utilisation in the presence of succinate, ADP and inorganic phosphate (Pi) was depressed. The pre-addition of BSA consistently lowered respiration rates with succinate and Pi in all preparations. The extent of endogenous inhibition of the adenine nucleotide translocase appeared unaltered by endotoxin in vivo.

Animals↗
PubMed1979

A comparative analysis of Cannabis material.

Extracts of 100 plant-like or resinous materials were analyzed for CBD, CBC, delta 9-THC, and CBN by GC using two different column packings and by GC-MS. Our independent identification of these cannabinoids confirmed those of other forensic science analysts who used microscopic examination, the Duquenois-Levine color test, and TLC for their analyses of the same samples. The identifications of cannabinoids by forensic acience analysts using TLC were corroborated by GC-MS analysis of hexane extracts of appropriate chromatogram spots.

Cannabinoids↗
PubMed1978

Identification of a nitrone as an in vitro metabolite of N-methylamphetamine.

The relatively labile nitrone, alpha-methyl-(N-methylene) benzeneethanamine N-oxide was isolated from incubates of (+/-)-N-methylamphetamine with fortified liver honogenates from rats and rabbit. Identification of the nitrone was confirmed directly by gas chromatography and gas chromatography mass spectrometry and, after its conversion to isoxazolidine adducts by the action of methyl and ethyl acrylate. An authentic sample of the nitrone was synthesized unequivocally form N-hydroxyamphetamine and formaldehyde. The isomeric nitrone, N-(alpha-methylbenzeneethylidene) methylamine N-oxide, was also synthesized and its gas chromatographic and gas chromatographic mass spectrometric characteristics determined to confirm that the metabolically formed nitrone was not N-(alpha-methylbenzeneethylidene) methylamine N-oxide. Two previously unreported metabolites of (+/-)-Nmethylamphetamine, N-hydroxyamphetamine and 1-hydroxy-1-phenyl-2-propanone, were isolated from rat in vitro experiments; the latter metabolite was not produced in vitro by rabbit liver homogenates.

Amphetamines↗
PubMed1978

Influenza and ischaemic heart disease--a possible trigger for acute myocardial infarction?

Prompted by a clinical observation of an increase in hospital admissions for acute myocardial infarction during an influenza outbreak, a study was designed to examine the number of deaths from ischaemic heart disease (IHD) at the time of influenza. Deaths from IHD were found to be increased at all ages, and particularly in younger age groups when deaths attributed specifically to acute myocardial infarction are considered. The question of whether influenza could act as a precipitating factor in acute myocardial infarction is discussed, together with a possible mechanism.

Adult↗
PubMed1978

Degradation of (--)-ephedrine in solution and during extraction with diethyl ether.

Significant losses occurred during the extraction of small quantities of ephedrine from aqueous media using either regular or analytical grades of diethyl ether. The losses were, at least in part, caused by reaction of the ephedrine with aldehydic impurities in the ether; three substituted oxazolidines were identified, using g.l.c. and g.l.c-ms. These and one other oxazolidine were synthesized and characterized by g.l.c., g.l.c.-ms, nmr and infrared spectroscopy. Alternative mechanisms for ephedrine breakdown were considered. Ephedrine was separately oxidized by three different oxidizing agents and also irradiated by ultraviolet light; the products were characterized by g.l.c., g.l.c.-ms. A method for the purification of diethyl ether is recommended to minimize ephedrine breakdown.

Chemical Phenomena↗
PubMed1978

Species differences in the in vitro metabolic reduction of the amphetamine metabolite, 1-phenyl-2-propanone.

Marked differences were observed, in the ability of fortified 9000 g liver homogenate supernatants from three species to reduce 1-phenyl-2-propanone to the corresponding alcohol. This metabolic keto-reduction was negligible in homogenates from the rat and extensive in the rabbit; guinea-pig liver homogenates had intermediate ability. Metabolic oxidation of 1-phenyl-2-propanol was negligible in all three species. The amount of deamination of amphetamine and of N-n-propylamphetamine was approximately equal, in vitro, in rats and guinea-pigs but two to three times greater in liver homogenates from rabbits. Approximately three times more deaminated products were formed from the in vitro metabolism of N-n-propylamphetamine than from amphetamine metabolism by all three species.

Acetone↗
PubMed1977

Artificial insemination with donor semen.

Fifty-three consecutive couples requesting artificial insemination with donor semen are presented. Insemination was carried out with fresh semen. Forty-three proven pregnancies were achieved with a mean of 3-4 treatment cycles per pregnancy. Psychological and legal aspects relating to this method of treatment are discussed.

Attitude to Health↗