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Biomedical subjects

M Thomas

Publications and source records attributed to M Thomas.

At least 937 records · Page 52Linked to original sources
PubMed1976

[Study of factors favoring infection in total hip prosthesis. Twenty-five observations].

The authors report 25 cases of infection following total hip replacement and individual factors are analysed. The role of immunological abnormalities is discussed. They distinguish early infection due to the operative conditions from late infection where individual factors are the most important. A few preventive measures are proposed, they emphasise the necessity of a large scale study of factors favouring late infection.

Hip Joint↗
PubMed1976

[Hypoglycemic complications of oral drug therapy of diabetes mellitus. 21 cases].

The authors present 21 cases of severe hypoglycaemic side effects in diabetics treated with oral sulphonylurea drugs, including two deaths. The medications involved the most frequently were glibenclamide followed by glybutamide and glicalzide. Such side effects often occur early and are unrelated to dose. The classical predisposing factors were noted : old age, renal insufficiency, hepato-cellular insufficiency, drug associations -- in particular oral anticoagulants and salicylates. The indications for such drugs in the treatment of diabetes are discussed. Their use seems doubly illogical in the case of late onset obesity diabetes since the latter is accompanied by cardiovascular complications. It is dangerous in the elderly, particularly sensitive to the risks of hypoglycaemia and in who the diagnosis of "diabetes" is too often made on inadequate grounds.

Age Factors↗
PubMed1976

Liquid chromatography of dansyl derivatives of some alkaloids and the application to the analysis of pharmaceuticals.

Derivatization of the alkaloids cephaeline, codeine, emetine, ephedrine, morphine, narcotine and others with dansyl chloride has been studied with the aim of developing a sensitive and specific liquid chromatographic method for these substances in complex pharmaceutical dosage forms. While codeine and narcotine do not react, the other compounds form completely substituted derivatives which possess maxima in their fluorescence emission spectra between 470 and 500 nm. The structure of the derivatives has been confirmed by nuclear magnetic resonance spectroscopy. The dansylated compounds have been separated by thin-layer chromatography and high-pressure liquid chromatography. The improved selectivity and sensitivity have permitted an analysis of these substances present in low concentrations in 10- 100-fold excesses of other drugs. Direct derivatization of syrups and aqueous slurries of capsules having a complex excipient and drug composition is feasible and time saving and serves as a pre-clean-up step. Detection limits are in the 1-10-ng range or better, depending on the efficiency of the detection device. The reproducibility of the method is limited by the derivatization step, but a relative standard deviation of less than 2% can be obtained. The analysis time for these pharmaceuticals may be reduced by at least one fifth of that required by conventional techniques.

Alkaloids↗
PubMed1976

Contraceptive efficacy of two different metals using a modified seven vector.

Early studies with copper suggested that few improvements in overall IUD performance could be obtained with the use of more than 200 mm2 of copper. Thus, the use of other metals paired with copper has been investigated. This report of two studies of the small Copper-7, one with zinc and the other with copper alone, suggests that the addition of zinc in the superior position of the small Cu-7 decreases the incidence of pregnancy and that the small Cu-7 may be associated with higher retention rates than the standard Cu-7.

Adult↗
PubMed1976

The LEM device in an immediate postpartum contraception program.

Experience with the LEM intrauterine device in an immediate postpartum program at the Jose Fabella Memorial Hospital, Manila, Philippines, is reported. During a 6-month period, the LEM was inserted in 1359 women immediately after normal term deliveries. The early expulsion rate was high, but removals for bleeding or pain were minimal. Pregnancy rates during the second 6 months of use were higher than those reported previously for postpartum insertions of the LEM device.

Adult↗
PubMed1976

Clinical experiences with naltrexone in 370 detoxified addicts.

Our studies have shown no evidence of toxicity and few side effects from naltrexone. It is a valuable adjunct in treating addicts who wish to be opiate free. Patients who drop out and return to treatment tend to remain longer with each successive readmission. Naltrexone has special potential for persons, such as an opiate-abusing physician for whom methadone maintenance is clearly inappropriate. A double-blind study has suggested that it may have value as a transitional treatment for detoxified methadone maintenance patients. Differences between naltrexone and cyclazocine suggest that a treatment combining these drugs should be explored.

Clinical Trials as Topic↗
PubMed1976

Solitary kidney and ageing as causes of low renin and aldosterone concentrations: relevance to "low-renin" essential hypertension.

1. As experimental models of reduced nephron population in man, (a) twelve men aged 15-32 years who had one kidney removed 1-13 years previously and (b) fourteen normotensive men aged 70-90 years were studied. Results were compared with those in eighteen normotensive men aged 18-28 years and eleven men aged 19-33 years with essential hypertension. 2. While the subjects followed a routine of normal diet and daily activity, measurements were made, after overnight recumbency and in the fasting state, of plasma volume and renin activity on one occasion in hospital and of blood pressure on five to fourteen occasions in the home. Blood pressure was also measured after standing for 2 min and plasma renin activity after 1 h standing, sitting or walking. Twenty-four hour urinary aldosterone excretion was also measured. 3. The measurements were repeated in the normotensive subjects and subjects in (a) and (b) above after 10 days of sodium-restricted diet (40 mmol of sodium/day). 4. The mean plasma renin activity (recumbent) in essential hypertensive subjects was higher than in normotensive subjects. In subjects of (a) and (b) above, it was lower than normotensive subjects, and was not increased by dietary sodium restriction in subjects of (a). 5. The mean aldosterone excretion level was lower in old normotensive subjects than in the other groups, and increased in each group after dietary sodium restriction. 6. Mean plasma volume/surface area was not different between the four groups and in normotensive, essential hypertensive and nephrectomized subjects but not subjects aged 70-90 years was negatively correlated with standing diastolic blood pressure.

Adolescent↗
PubMed1976

Hybridization of RNA to double-stranded DNA: formation of R-loops.

RNA can hybridize to double-stranded DNA in the presence of 70% formamide by displacing the identical DNA strand. The resulting structure, called an R-loop, is formed in formamide probably because of the greater thermodynamic stability of the RNA-DNA hybrid when it is near the denaturation temperature of duplex DNA. The rate of R-loop formation is maximal at the temperature at which half of the duplex DNA is irreversibly converted to single-stranded DNA (the strand separation temperature of tss) of the duplex DNA and falls precipitously a few degrees above or below that temperature. This maximal rate is similar to the rate of hybridization of RNA to single-stranded DNA under the same conditions. At temperatures above the tss the rate is proportional to the RNA concentration. However, at temperatures below tss the rate of R-loop formation is less dependent upon the RNA concentration. Once formed, the R-loops display considerable stability; the formamide can be removed and the DNA can be cleaved with restriction endonucleases without loss of R-loop structures.

Coliphages↗
PubMed1976

The use of a computer in an obstetric department.

Experience with a computer in an obstetric department is presented. A regular statistical analysis of the work of the department was readily available and computer printed summaries were produced for 86 per cent of the patients within one week of their discharge home. Solutions to problems encountered are discussed. It is concluded that a computer can be used economically and advantageously in this way even in hospitals without a computer on site. Future developments in the use of the computer are outlined.

Computers↗