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Biomedical subjects

M M Jones

Publications and source records attributed to M M Jones.

At least 217 records · Page 12Linked to original sources
PubMed1982

Growth of the pectoralis muscle of the house sparrow (Passer domesticus).

The pectoralis muscle from growing house sparrows was investigated using linear, gravimetric, histological and ultrastructural techniques. The structure of the muscle at different stages of development was discussed in relation to known behavioural activities, such as the onset of regular wing exercising and thermogenic shivering in the nestlings. Fibres in the pectoralis muscle of birds about to fledge (15 day nestlings) were similar in composition to fibres in muscles from fully fledged juveniles, with two exceptions. Firstly, numerous lipid droplets had accumulated adjacent to mitochondria in fibres from the pectoralis muscle of the nestlings. This lipid could act as a readily available source of energy for the birds on fledging. Secondly, masses of ribosomes and irregularly shaped myofibrils were present, indicating the continued elaboration of the contractile apparatus in fibres from the pectoralis muscle of the 15 day nestlings. The inefficient flight of newly fledged house sparrows may be accounted for by the size of the pectoralis muscle relative to total body weight. The total contractile material in the muscle of the birds about to fledge was estimated to be 60% or less of that found in fully fledged juveniles, while the body weight was nearly that of an adult bird.

Aging↗
PubMed1982

Antidotes for acute beryllium sulfate intoxication in mice.

Eleven water soluble chelating agents were tested as antidotes for acute beryllium sulfate intoxication in mice. The most effective of these was sodium 4,5-dihydroxy-1,3-benzenedisulfonate (Tiron). At the level of administration of beryllium used, aurin tricarboxylic acid is not an antidote.

Animals↗
PubMed1982

The effect of 2,3-dimercaptopropionic acid on distribution and excretion of 115mCd and 203Hg in rats.

The effect of 2,3-dimercaptopropionic acid (DMPA) on the excretion and distribution of 115mCd and 203Hg was studied in rats. After a single intravenous injection of 115mCdCl2 (at the dose of 500 micrograms of Cd2+.kg-1 b.wt.) no effect of DMPA on the distribution and excretion of 115mCd was observed. DMPA administration increased biliary and urinary excretion and decreased the content of 115mCd in liver and kidney in rats injected two subcutaneous doses of 115mCdCl2 (each dose 2500 micrograms of Cd2+.kg-1 b.wt.) at 48-hour intervals, five days before DMPA administration. DMPA administration 3 and 6 hours after a single intravenous injection of 203HgCl2 (at the dose of 600 micrograms of Hg2+.kg-1 b.wt.) increased significantly the urinary excretion of 203Hg and decreased 203Hg content in the liver and kidney. Distribution of 203Hg between the high- and low-molecular weight bile fractions (bile fractions 1 and 2) was influenced by DMPA more than in the case of 115mCd. This effect was more pronounced in in vitro than in in vivo experiments.

Animals↗
PubMed1982

Antagonism of acute copper(II)-induced renal lesions by sodium 2,3-dimercaptopropanesulfonate.

Acute copper(II) sulfate poisoning in the mouse induces renal tubular degeneration and necrosis. Timely administration of sodium 2,3-dimercaptopropane-sulfonate (DMPS) effectively prevented the development of the morphological renal sequelae of copper intoxication. During the time course of this study (5 days), no copper-induced hepatic lesions were observed. DMPS and its preformed copper complex possess low inherent toxicity with no hepatorenal lesions occurring over a 5-day period. These findings suggest that DMPS may be an effective antidote in acute and chronic copper poisoning in humans.

Acute Kidney Injury↗
PubMed1981

Structural requirements for chelate antidotal efficacy in acute antimony(III) intoxication.

The LD50 for i.p. potassium antimonyl tartrate was determined to be 54.6 mg/kg in mice, with a 95% confidence range of 48.4 to 61.7 mg/kg. An examination of the antidotal efficacy of a number of different structural types of chelating agents showed that very few types were able to act as antidotes when potassium antimonyl tartrate was administered i.p. to mice at a level of 120 mg/kg. The most effective antidotes, by a substantial margin, were the water soluble vicinal dithiols: 2,3-dimercaptosuccinic acid and sodium 2.3-dimercaptopropane-1-sulfonate, with the first of these being significantly better than the second. Appreciably less effective, but still useful, was D-penicillamine. At this level of administration of antimony(III), BAL is not an effective antidote. Among other chelating agents which were also not effective at this level of antimony(III) are tartaric acid, EDTA, cysteine, sodium diethyldithiocarbamate and potassium dithiooxalate.

Animals↗
PubMed1981

Tiron (sodium 4,5-dihydroxybenzene-1,3-disulfonate) as an antidote for acute uranium intoxication in mice.

Tiron (sodium 4,5-dihydroxybenzene-1,3-disulfonate) administered intraperitoneally was found to antagonize the lethal action of intraperitoneally induced uranium(VI) toxicity. In a comparative study Tiron was evaluated against Na3CaDTPA (sodium calcium diethylenetriaminepentaacetate). The ability of these compounds to detoxify the uranyl ion in simple and complexed form and their efficacy in delayed treatment regimens and determined. Toxicities of the complexes were assessed by the administration of uranyl acetate at levels of 40 mg/kg or 80 mg/kg complexed at a mole ratio of 3:1 or 2:1 of chelating agent to uranium, prior to injection, followed by two additional doses of chelating agent given one and three hours later at a 10:1 mole ratio of chelating agent to uranium. Therapy in delayed treatment regimens consisted of three injections of antidote given 20 minutes, one hour, and three hours, at a 10:1 mole ratio of chelating agent to uranium, subsequent to an injection of 40 mg/kg uranyl acetate. Survival rates for animals receiving multiple injections of Tiron were enhanced over those receiving Na3CaDTPA. The low inherent toxicity of Tiron may make it appropriate for possible clinical application.

1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium ↗
PubMed1980

A placebo-controlled trial of ethinyl oestradiol and norethisterone in climacteric women.

A placebo-controlled trial has shown that 15 microgram of ethinyl oestradiol is as effective as 25 microgram daily in reducing both menopausal symptoms and the urinary excretion of calcium and hydroxyproline. Norethisterone 5 mg daily also showed a significant reduction in the climacteric symptoms but was less effective than either of the ethinyl oestradiol doses.

Calcium↗
PubMed1980

Rise in plasma alkaline phosphatase at the menopause.

1. Plasma alkaline phosphatase activity and urine hydroxyproline excretion were measured in age-matched premenopausal and postmenopausal women. 2. Both measurements were found to be significantly higher in postmenopausal women. 3. It is proposed that the rise in the plasma alkaline phosphatase, like that in the hydroxyproline excretion, may reflect the onset of bone loss that occurs after the menopause.

Alkaline Phosphatase↗
PubMed1980

Wakefullness and reduced rapid eye movement sleep: studies with prolintane and pemoline.

1 Effects of prolintane (15 and 30 mg) and pemoline (60 and 100 mg) on sleep were studied in six healthy adult males. Sleep was assessed by electroencephalography and by analogue scales. 2 Prolintane (15 and 30 mg) reduced rapid eye movement (REM) sleep both by delaying the first period (P < 0.05 and < 0.001 respectively) and by reducing total REM sleep (P < 0.05 and < 0.001 respectively). In some subjects there were increased awakenings during the early part of the night, and in two subjects long periods of wakefulness occurred. 3 With pemoline (60 and 100 mg) sleep duration was marked reduced (P < 0.001). There was evidence in some subjects of delay to the first REM period, and reduced percentage REM sleep (P < 0.01). Shortened and fragmented sleep with 60 and 100 mg were associated with reduced sleep efficiency indices (P < 0.001), and shorter sleep period times led to reduced REM/NREM ratios. Absence of an effect on REM latency for the subjects as a group may be related to relatively slow absorption. 4 The heterocyclic amphetamine derivatives have variable effects on sleep. The differences may be dose related, and wakefulness and reduced REM sleep may be seen together or separately. Alterations in sleep occur with doses of pemoline and prolintane which also modify performance.

Adult↗
PubMed1980

Comparison of standard chelating agents for acute mercuric chloride poisoning in mice.

A comparison in mice has been made of the effectiveness of five chelating agents used clinically for acute mercuric chloride poisoning, or recommended for such use. The compounds examined were N-Acetyl-D,L-penicillamine (NAPA), D-penicillamine (DPA), 2,3-dimercaptosuccinic acid (DMSA), sodium 2,3-dimercaptopropanesulfonate (DMPS), and 2,3-dimercaptopropanol-1 (BAL). The test of effectiveness was their ability to reduce the mortality of acute mercuric chloride poisoning when administered 20 minutes after the mercury at chelate:mercury mole ratios of 10, 15, 20, and 30. All except BAL were found to be effective at the highest mole ratio tested, but N-Acetyl-D,L-penicillamine and sodium 2,3-dimercaptopropanesulfonate were significantly more effective than DMSA and BAL at mole ratios of 10:1. The relative effectiveness does not correlate with available data on stability constants. The toxicity of BAL itself becomes apparent at mole ratios of 20:1 and above.

Animals↗
PubMed1980

The relative effectiveness of some chelating agents in acute copper intoxication in the mouse.

The relative efficacy of 9 chelating agents in offsetting the acute toxicity of ip copper sulfate has been determined. Included in this group are almost all of the compounds which have been used in, or suggested for use in human cases of acute or chronic copper toxicity. Under the conditions used, sodium 2,3-dimercapto-1-propanesulfonate is by far the most effective antidote of the compounds examined.

Animals↗
PubMed1980

Relative efficacy of chelating agents as antidotes for acute nickel(II) acetate intoxication.

The relative efficacy of 14 chelating agents in alleviating acute nickel(II) acetate (ip) intoxication has been determined. The LD50 for ip nickel(II) acetate in mice was found to be 45.7 mg/kg with a 95% confidence limit of 39.2--53.3 mg/kg. For a level of 62 mg/kg ip of nickel(II) acetate (i.e. approximately LD90 or greater), the most effective antidotes were D-penicillamine and Na2CaEDTA, but several other chelating agents with rather different arrangements of donor atoms were almost as effective. The acetylation of the amino group in penicillamine to give N-Acetyl-D,L-penicillamine effectively destroys the antidotal action, as would be expected if coordination to the nitrogen were essential to the process.

Animals↗
PubMed1979

Restrictions on the applicability of mixed ligand chelate therapy (MLC) in acute cadmium intoxication.

An experimental study of the comparative effectiveness of single and mixed ligand chelates as antidotes for acute cadmium poisoning reveals few appreciable differences when the cadmium (as cadmium chloride or acetate) is administered ip. In each case the mixed ligand chelate system showed little or no improvement over the results obtained with the most effective of the individual components. This procedure, using mixed ligand chelate systems, may well be one which is limited to conditions more narrowly similar to those reported by Schubert and Derr (1978). It does not appear to possess the broad range of applicability which might be expected from the equilibrium principles on which it is based. By comparing our data with previous studies it can be seen that Na2CaEDTA is capable of offsetting the lethality of ip cadmium chloride when the latter is administered at rather higher levels that have previously been counteracted by any of the sulfur containing chelating agents tested to date.

Acute Disease↗