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Biomedical subjects

C Scott

Publications and source records attributed to C Scott.

At least 217 records · Page 12Linked to original sources

Acute haemodynamic effects of oral prenalterol in severe heart failure.

The acute haemodynamic effects of oral prenalterol were studied in 14 patients with severe heart failure (NYHA class III) due to ischaemic heart disease. All had received treatment with digoxin, diuretics, and in most cases vasodilators. Prenalterol was administered at two hourly intervals to give cumulative doses of 20, 50, and 100 mg and mean plasma concentrations of 53, 97, and 175 nmol/l. Haemodynamic measurements were made two hours after each dose with Swan-Ganz catheterisation; cardiac output was measured by thermodilution. There were no significant changes in heart rate, mean arterial pressure, or pulmonary artery diastolic pressure after the drug. Cardiac index rose significantly after 50 mg and 100 mg prenalterol. Oral prenalterol has a beneficial short term haemodynamic effect in patients with severe heart failure. If this effect is sustained prenalterol may be of value in the long term management of patients with this disabling condition.

Adrenergic beta-Agonists↗

[Value and limitations of the computed x-ray tomographic measurement of vertebral mineralization].

An experimental study of the reproducibility and exactitude of densitometric measurements obtained by CT scanning showed: 1) the existence of marked variations due to factors related to the apparatus: beam energy, filtration, electronics, direction of rotation, reconstruction software; 2) that the structure of the object was also an influencing factor: variations in tissues surrounding the vertebra, and variations in bone density as a function of the plane in the vertebral body, and in fat content in the spongy tissue. Any measurement by CT scan of the mineral density of the vertebral body requires the use of a calibration phantom, strict definition of the volume to be measured, and routine correction for hypodensity induced by fat when necessary. Results under these conditions are reproducible and useful for the diagnosis of rarefying osteopathies.

Adolescent↗

Characterization of two metastatic subpopulations originating from a single human colon carcinoma.

Two separate cell lines originating from distinct metastatic deposits in a patient with a primary colonic carcinoma have been established both in vivo and in vitro. One metastasis, OM-1, was found in the omentum, and the other, HOT-3, was located on the ovary. These two metastases differ in several significant characteristics, including growth kinetics and the production of carcinoembryonic antigen by the cultured cells. OM-1 xenograft tumors contain about 8-fold more colonic mucin antigen than do HOT-3 heterografts. Similarities also exist. Both cell lines contain extra chromosomes in the A group, and both are missing chromosomes in Pair 14 of the D group and in Pair 18 of the E group. Xenograft tumors from these two metastases contain equivalent amounts of carcinoembryonic antigen and nonspecific cross-reacting antigen. These metastases developed through a process of progression and natural selection that occurred during the course of the patient's disease. Thus, the cell lines established from them provide material which may be used to study functional intraneoplastic diversity.

Antigens, Neoplasm↗

Low-Income Energy Assistance Program.

In fiscal year 1981, Congress appropriated $1.85 billion for home heating assistance to help low-income households meet rapidly rising energy costs. Eligibility for payments was based on income and energy-cost criteria. This procedure represented a departure from the earlier Federal focus of assisting households facing emergency hardships. Funds for the Low-Income Energy Assistance Program were allocated to the 50 States and District of Columbia, six territories, and 55 Indian tribal organizations. This article presents program data and information on the characteristics of the more than 17 million persons who received aid under this program.

Air Conditioning↗

Function of the Oxford Ventilator at high pressure.

The Penlon Oxford Ventilator functioned well to 6 atmospheres absolute in an air environment and to 31 atmospheres absolute in an oxyhelium environment, as assessed remotely utilising a lung ventilator performance analyser. It features easily comprehensible controls and functions, and its use in prolonged ventilatory support could be taught to non-anaesthetists with relative ease. In addition to its relative simplicity, it is reliable, readily available, and requires only fitting with a male Schrader valve for use at high pressures. The ventilator is recommended for ventilatory support under extreme hyperbaric conditions.

Air↗

Diastrophic dysplasia: the death of a variant.

Diastrophic dysplasia is a distinct autosomal recessive disorder originally described in 1960. Since that time, a number of patients with similar but less severe involvement have been diagnosed as having a "diastrophic variant" disorder. This study reviews the radiological features of classic diastrophic dysplasia and compares them with the radiological findings in 26 patients with the diastrophic variant disorder. It is concluded that there is a wide variability in the phenotypic expression of diastrophic dysplasia even within sibships, and that cases of diastrophic variant disorder are actually mild forms of diastrophic dysplasia.

Adolescent↗

Carcinosarcoma of the bladder.

We present 2 cases of carcinosarcoma of the bladder. These tumors are considered as true admixtures of epithelial and mesenchymal neoplastic cells rather than 2 separate neoplasms that touch or marginally invade each other. Although the etiology of this tumor is unclear it tends to be aggressive and probably requires an early radical operation with adjuvant radiotherapy and chemotherapy.

Aged↗

Fluorescence properties of o-phthaldialdehyde derivatives of amino acids.

The fluorescence properties of the products formed by reaction of o-phthaldialdehyde with amino acids and their derivatives, in the presence of thiol compounds, have been studied. The emission spectra, quantum yields, and lifetimes depend on the primary amine and thiol compound used; the observations confirm the report (Simsons, S.S., Jr. and Johnson, D.F. (1978) J. Org. Chem 43, 2886--2891) that the product incorporates molecules of all three types of compounds. The fluorescence quantum yields of o-phthaldialdehyde derivatives of the naturally occuring amino acids ranged from 0.33 to 0.47, using 2-mercaptoethanol as the thiol compound. The fluorescence lifetimes were about 18--20 ns. Lower quantum yields were obtained when mercaptoethanol was replaced by dithiothreitol or ethnethiol. Derivatives of amino acid amides and peptides had quantum yeilds as low as 0.03, due to quenching by the carboxamide group. The intramolecular quenching was relieved by the detergent, sodium dodecyl sulfate, and by dimethylsulfoxide. Monosubstituted lysine exhibited a normal fluorescence, but the di-substituted product was largely quenched, presumably due to interaction between the two isoindole fluorophors. Fluorscence stopped-flow experiments showed that the alpha- and epsilon-amino groups reacted at different rates, with the epsilon-amion group reacting 10 times faster, with a t 1/2 of about 6 s under pseudo first order conditions at pH 9.0 with 10(-3) M o-phthaldialdehyde. The amount of instability shown by the o-phthaldialdehyde derivatives depended on the thiol compound used, the primary amine involved, and the solvent. Cysteine and o-phthaldialdehyde reacted to give an unstable, weakly fluorescent product; but cysteine could be assayed normally if its sulfhydryl was blocked. The o-phthaldialdehyde reagent was discussed in relation to fluorescamine, another reagent for primary amines.

Amino Acids↗

A new assay for the measurement of mediator release from rat peritoneal mast cells.

In this report, we describe a new in vitro experimental system for monitoring the release, and inhibition of release, of [3H]-serotonin from rat peritoneal mast cells, which can be used as a novel screen for evaluation of compounds effective in immediate hypersensitivity reactions. This assay is an improvement on existing assays since the cells are not required to be exposed to hormones at any time during the procedure. In this assay, 1 microgram/ml of compound 48/80 consistently produced a 6- to 8-fold-increase in release of serotonin with a low background release of 4-5%. Disodium chromoglycate (DSCG), a standard inhibitor of histamine release, effectively inhibited compound-48/80-stimulated serotonin release with an average I50 of 2.1 X 10(-4) M. Several other potential antiasthmatic agents were far more potent than DSCG.

5-Hydroxytryptophan↗

Persistent measles virus infection in vitro and in man.

The characteristics of cell lines persistently infected with measles virus are described. Molecular mechanisms for measles virus-persistence in vitro as well as in human disease include defective interfering particles, mutant virus strains, proviral DNA, and nonpermissive cell types. The role of measles virus in subacute sclerosing panencephalitis and evidence for measles virus infection in multiple sclerosis, Paget's disease, and systemic lupus erythematosus are discussed.

Antibodies, Viral↗