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Biomedical subjects

J F Thompson

Publications and source records attributed to J F Thompson.

At least 325 records · Page 18Linked to original sources
PubMed1981

Liver resection for neoplasm.

Major hepatic resections can now be performed with much greater safety than formerly. This is largely a consequence of improved surgical and anesthetic techniques, which have in turn resulted from better understanding of the anatomy, physiology and biochemistry of the liver. The treatment of liver tumours by resection must be reappraised in the light of these advances. This paper reports twelve patients who have undergone major hepatic resection for neoplasm at the Royal Prince Alfred Hospital over a ten-year period. The current indications for such surgery in the treatment of benign and malignant liver tumours are reviewed, and the results discussed.

Adenoma↗
PubMed1981

Cimetidine-benzodiazepine drug interaction.

The effect of cimetidine on the metabolism of benzodiazepines is discussed. Studies of cimetidine's inhibition of benzodiazepine metabolism by liver microsomal enzyme pathways are described. Cimetidine is known to have this effect on the metabolism of diazepam and chlordiazepoxide, and because chlorazepate and prazepam are similarly metabolized, cimetidine is likely to have the same effect on the metabolism of these drugs. Oxazepam and lorazepam are two benzodiazepines not metabolized by liver microsomal enzymes, but are thought to be glucuronidated in peripheral tissue by glucuronyl transferase. Cimetidine has been shown not to alter the pharmacokinetics of lorazepam or oxazepam when administered concurrently with either of these benzodiazepines. When it is necessary to treat a patients receiving cimetidine with a benzodiazepine, oxazepam or lorazepam may be the drug of choice.

Animals↗
PubMed1979

Intravaginal pressure assessed by the Kegel perineometer.

A first attempt was made to provide norms for intravaginal pressure in normal women measured by the Kegel perineometer. Data obtained from 78 white females and 64 black females indicate that resting pressure approximates 5 mm Hg and pressure with appropriate pelvic musculature contracted reaches an average of 15 mm Hg. The difference between resting and contracted pressures is unrelated to the former. There is a moderate negative correlation between number of vaginal births and contracted pressure in the white sample.

Adult↗
PubMed1979

The carcinoid tumour.

Carcinoid tumours are by no means rare. The wide range of sites in which they occur is explained by their origin from APUD cells of the neural crest. These cells migrate to all parts of the alimentary tract during embryonic life, and ultimately are found as well in various gut derivatives such as the respiratory, pancreatic and biliary systems. On the basis of a series of 31 carcinoid tumours seen at the Royal Prince Alfred Hospital in a five-year period, the distinctive clinical and histological features of carcinoids of foregut, midgut and hindgut origin are reviewed. Diagnosis, treatment and results are discussed, and recommendations regarding management of the patient with a carcinoid tumour are given.

Adolescent↗
PubMed1979

Drug utilization and prescribing patterns in a skilled nursing facility: the need for a rational approach to therapeutics.

A study was made of 50 patients drawn at random from a Skilled Nursing Facility (SNF) attended by seven physicians. For 59 percent of these patients, polypharmacy was practiced but no substantiating diagnoses were recorded. Approximately half of the drugs were administered pro re nata. More drugs were prescribed in potentially toxic dosages than in subtherapeutic dosages. The risk of an adverse drug reaction (ADR) was most often associated with anticholinergic agents, sedative-hypnotic drugs, and neuroleptics (thioridazine and chlorpromazine), particularly when prescribed concurrently. Risk of an ADR was highest when a drug was prescribed without recording a definite diagnostic indication. Lack of consistency by individual physicians in their approaches to the therapy of similar disease entities in comparable patients tended to support the concept of peer review in SNFs and also the need for teaching a rational approach to therapeutics in SNFs based on clinical pharmacology as applied to the elderly.

Aged↗
PubMed1978

Isolation of polyribosomes and messenger RNA active in in vitro synthesis of soybean seed proteins.

Polyribosome preparations containing low proportions of monosomes to polyribosomes have been isolated from developing seeds of Glycine max L. Merrill using a high pH-high KCl buffer. The polyribosomes were functional in in vitro protein synthesis reactions using wheat germ 23,000g supernatant preparations. Results of experiments using aurintricarboxylic acid indicated that most or all of the amino acid incorporation in vitro resulted from the completion of nascent polypeptides associated with the isolated polyribosmes. RNA purified from polyribosome preparations by affinity chromatography on oligo(dT)-cellulose was also active in vitro, and had different Mg and K requirements for translation than did the polyribosomes. Translation of oligo(dT)-cellulose-purified mRNA was inhibited by the addition of 7-methylguanosine 5'-phosphate, suggesting that soybean mRNAs are "capped" at their 5' ends. Some, but not all, of the products of these reactions were identical in electrophoretic mobility to radioactive polypeptides of storage proteins produced in soybean cotyledons grown in culture.

Journal Article↗
PubMed1977

A multiclass, multiresidue analytical method for pesticides in water.

A procedure is reported for the multiclass, multiresidue analysis of pesticides in water. Compounds are extracted from water with methylene chloride, and the extract is concentrated by an evaporative technique utilizing reduced pressure and low temperature. Compounds are segregated into groups using a column of partially deactivated silica gel and sequential elution with four different solvent systems. Carbamate residues, converted to their 2,4-dinitrophenyl ether derivatives, are gas chromatographed via electron capture detection as are the parent compounds of the organohalogen compounds. Organophosphorus compounds are determined by gas chromatography using a flame photometric detector. Recovery studies were conducted on 42 halogenated compounds, 38 organophosphorus compounds, and 7 carbamates. Fifty-eight of 87 compounds tested produced recoveries in excess of 80%; another 13 compounds yielded recoveries exceeding 60%, while the recoveries on the remaining 16 compounds fell below 60%.

Carbamates↗
PubMed1977

Formation of N-acetylglutamate by extracts of higher plants.

The enzymic synthesis of N-acetylglutamate was studied in extracts of higher plant tissues, especially in sugar beet leaves (Beta vulgaris L.). Sugar beet leaves had an enzyme that transferred the acetyl group either from acetyl-CoA or from N(2)-acetylornithine to glutamate. The enzyme was so unstable that special precautions were necessary for its detection and appreciable purification was impossible. The Km values were 2.5 and 0.025 mM for acetyl-CoA and N(2)-acetylornithine, respectively. The Km for glutamate was 23 mM with acetylornithine-glutamate transacetylase and 2.7 mM with acetyl-CoA-glutamate transacetylase. The pH optimum for acetyl-CoA-glutamate transacetylase was about 7.2 whereas that for acetylornithine-glutamate transacetylase was about 8.3. Acetylphosphate, N(2)-acetyl-2,4-diaminobutyrate, propionyl-CoA, and succinyl-CoA were not substrates.Arginine inhibited the acetyl-CoA-glutamate transacetylase and acetylglutamate phosphokinase but had no effect on the acetylornithineglutamate transacetylase. Related compounds had either no effect or much less than arginine. Arginine had no effect on enzyme levels.Acetyl-CoA-glutamate transacetylase was also found in Raphanus sativus L., Glycine max L. Merr., Arachis hypogaea L., Brassica rapa L., and Pisum sativum L. Acetylornithine-glutamate transacetylase was found in all of the above species plus Zea mays L., Avena sativa L., and Triticum aestivum L.

Journal Article↗
PubMed1975

Prenatal sex detection with endocervical smears: successful results utilizing Y-bodyfluoroscence.

Highly equivocal results, regarding procedures for the prenatal detection of fetal sexls found in the endocervix, are reported in the literature dating from 1971. The far-reaching genetic and obstetric implications of such procedures led us to investigate endocervical smears from 36 patients (taken during all three trimesters) and study the validity and practicality of this test. Fetal sex was correctly predicted in 31 of 36cases and all 18 male predictions delivered males. In addition, many previously reported and newly found sources of error were encountered and evaluated. It is concludedthat there are indeed cells of fetal origin being shed into the endocervix and they canbe used as a reliable indicator of fetal sex in all three trimesters.

Cervix Uteri↗
PubMed1975

Acetyl coenzyme a-glutamate acetyltransferase and N-acetylornithine-glutamate acetyltransferase of chlorella.

The enzymic formation of acetylglutamate has been studied in Chlorella vulgaris extracts. Acetyl CoA and N(2)-acetyl-l-ornithine served as substrates for glutamate acetylation whereas acetylphosphate, N(5)-acetyl-l-ornithine, and N(2)-acetyl-2,4-diamino butyrate were ineffective. Acetyl CoA-glutamate transacetylase and acetylornithine-glutamate transacetylase activities have been purified over 180-fold with no indication of any separation of activities. The acetyl CoA activity was more labile than acetylornithine activity so that preparations having acetylornithine-glutamate transacetylase activity but no acetyl CoA-glutamate transacetylase activity were obtained. The two acetylating activities appear to be properties of one enzyme with one portion more easily denatured.Both acetylating activities had pH optima between 8 and 8.5. The Km value for glutamate was 3 mm for both activities. The Km values were 0.2 mm for acetylornithine and 3.2 mm for acetyl CoA. Arginine inhibited acetyl CoA-glutamate transacetylase (Ki = 0.94 mm) and acetylglutamate phosphokinase (Ki = 0.5 mm) but had no effect on acetylornithine-glutamate transacetylase. The lack of an inhibitory effect of proline on any of the three enzymic activities indicates that acetylglutamate is not a normal intermediate in proline biosynthesis. Growth of Chlorella with arginine as a nitrogen source had no effect on enzyme levels, showing that end-product repression is not a control factor in arginine biosynthesis in Chlorella. In Chlorella, arginine controls its own biosynthesis by inhibiting acetylglutamate phosphokinase and controls the level of acetylated intermediates by inhibiting acetyl CoA-glutamate transacetylase.

Journal Article↗