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Biomedical subjects

C Barnes

Publications and source records attributed to C Barnes.

At least 127 records · Page 7Linked to original sources
PubMed1990

Affinity purification of a major Alternaria allergen using a monoclonal antibody.

An extract of Alternaria (ALT) was passed through an affinity column containing a monoclonal antibody directed to ALT. After washing the column, a single glycoprotein was eluted using 0.1 M glycine (pH 3.0). This glycoprotein accounted for 13% of the dry weight of our ALT preparation and had a carbohydrate to protein ratio of 0.35 as compared with 3.2 for the whole ALT extract. Its molecular weight was 70 kD by SDS-PAGE and isoelectric point was 3.5 by IEF. Though individual sensitivities varied, 14/16 patients skin reactive to ALT were also reactive to this glycoprotein. Quantitative skin tests of extracts adjusted to the same dry weight per volume showed that it required about a four times greater concentration of the purified glycoprotein to give a wheal size equal to whole Alternaria. The ability to purify large amounts of this allergen with affinity chromatography should make its complete characterization possible.

Adolescent↗
PubMed1989

Incorporation of magnesium into rat dental enamel and its influence on crystallization.

The incorporation of magnesium into the enamel of immature rats was studied by chemical analysis and X-ray diffraction. Magnesium solutions were injected subcutaneously and later intra-orally into growing rats. Increased magnesium was detected in the enamel at the late developmental stage, and a delay in enamel mineralization resulted from increased magnesium uptake. Incisal enamel from the Mg-injected rats had significant line-broadening on X-ray diffraction, characteristic of poorly crystallized enamel.

Animals↗
PubMed1989

A controlled evaluation of arthritis education.

The benefits of patient education for those with chronic arthritis are well documented. Informed patients should practice self care more often, and may show reduced disability from their disease. An important question relates to maintenance of the knowledge and skills acquired in educational programmes. This prospective study evaluated an education programme for people with rheumatoid arthritis (RA) and osteoarthritis (OA). The intervention group participated in a comprehensively planned six session behaviourally based programme. A questionnaire was given to 100 patients and 95 matched but non-random controls before the programme, 1 month later, and at 3 and 12 months. The intervention group demonstrated improvements in knowledge, self-reported health behaviour and disability scores at 12 months, compared to the controls. No differences were reported in symptoms, compliance with therapy, pain perception, and locus of control.

Arthritis, Rheumatoid↗
PubMed1988

The effect of solvation on the ultrasonic absorption of bovine serum albumin solutions.

The role of solvation and structural equilibria in determining the ultrasonic absorption of aqueous solutions of bovine serum albumin has been investigated using chemical agents to denature the protein in solution. The agents used were methanol, ammonium sulphate, and guanidine hydrochloride. Two different techniques of measurement were used to cover the frequency range 200 kHz to 30 MHz. The results show that only guanidine hydrochloride produces a significant change in ultrasonic absorption even though the other agents were used at concentrations close to those which would produce protein precipitation. The conclusion is that in the above frequency range structural and solvation-related equilibria are unimportant and only perturbation of proton-transfer equilibria associated with the protein amino acid residues leads to the bulk of the ultrasonic absorption.

Absorption↗
PubMed1988

Low-frequency ultrasound absorption in aqueous solutions of hemoglobin, myoglobin, and bovine serum albumin: the role of structure and pH.

New measurements on ultrasound absorption of aqueous solutions of the three globular proteins, bovine hemoglobin, horse heart myoglobin, and bovine serum albumin, at 20 degrees C are reported for the frequency range below 1.2 MHz and, in the case of hemoglobin and bovine serum albumin, to a limited extent for the range 2-30 MHz. The effect of protein conformation has been investigated by use of a range of denaturants and by change of pH. A much more detailed description of protein interactions emerges from the low-frequency studies than was possible hitherto. Specific absorption processes for myoglobin and bovine serum albumin peak in the neighborhood of pH 4.2. The process for myoglobin has a relaxation frequency between 1 and 2.6 MHz, while for bovine serum albumin the frequency is as low as 70 kHz. Both processes can be related to conformational changes in the molecules. In the case of hemoglobin, an absorption process with a relaxation frequency of 600 kHz is found that can be attributed to the dissociation equilibrium of the quaternary structure of the molecule and can be considerably enhanced by denaturants or pH change from neutral to acid conditions. Measurements at frequencies down to 200 kHz have also permitted a more thorough investigation of proton-transfer reactions at carboxyl and amino groups in these proteins and of the effect of pH on these reactions.

Absorption↗
PubMed1988

Limitation of myocardial infarction by early infusion of recombinant tissue-type plasminogen activator.

In a double-blind randomized trial involving five Sydney hospitals and the city ambulance paramedical service, 145 patients with a first evolving myocardial infarction and with onset of pain less than 2.5 (mean 1.9 +/- 0.5 [SD]) hr previously were allocated to intravenous infusion of 100 mg recombinant tissue-type plasminogen activator (rt-PA) or placebo over 3 hr. The groups at entry were similar. At assessment 21 days later, left ventricular ejection fraction measured both by contrast and radionuclide ventriculography was higher in the rt-PA compared with the placebo group (61 +/- 13%, n = 64, vs 54 +/- 14%, n = 62, contrast, 2p = .006; 52 +/- 13%, n = 66, vs 48 +/- 13%, n = 62 isotope, 2p = .08). This indicates limitation of myocardial infarction by rt-PA.

Adult↗
PubMed1988

Sarcoidosis: atypical presentation associated with features of systemic lupus erythematosus.

A 52-year-old woman presented with rash, bilateral uveitis and polyarthritis of her hands. Laboratory tests were consistent with the diagnosis of systemic lupus erythematosus (SLE). Ten years later she developed dyspnea associated with bihilar lymphadenopathy. Lung function tests showed a restrictive pattern and bronchial biopsy revealed the presence of noncaseating granulomata. We report this rare concomitant appearance of SLE and sarcoidosis.

Antibodies, Antinuclear↗
PubMed1986

Water intoxication in the course of an acute schizophrenic episode.

In the course of a schizophrenic episode a woman drank a large amount of tap water. She was found nearly unconscious in her room and was admitted to the clinic. Very low sodium and potassium values in the serum were indicative of water intoxication. During hospitalization she also suffered from several convulsive seizures. After replacement of electrolytes she recovered within 12 to 17 h. This case report demonstrates that water intoxication should also be considered in cases of suspected poisoning with other substances such as drugs. In all these cases an electrolyte status is indicated.

Acute Disease↗
PubMed1986

Ultrasonic absorption of bovine serum albumin solutions in the frequency range 60 to 160 kHz.

The ultrasonic absorption of the globular protein bovine serum albumin in aqueous solution has been measured in the frequency range 60 to 160 kHz using a 2-1 spherical resonator. The effect of pH change and of the denaturants urea, guanidine hydrochloride, and sodium dodecyl sulfate on the absorption loss has been studied. It is concluded that a significant ultrasonic absorption process exists which is related to structural helix-coil transition equilibria. For native protein the maximum loss appears to occur at a frequency at least as low as 70 kHz for a pH of about 4.2. This loss process is distinct from those arising from proton-transfer equilibria perturbations which are manifest at pH 3.2 and 11.6 and at peak frequencies of 400 kHz and above.

Animals↗
PubMed1985

Ultrasonic absorption of bovine serum albumin solutions in the frequency range 200 kHz-1 MHz.

The ultrasonic absorption of solutions of two electrolytes, magnesium and manganous sulfates, and also of the globular protein bovine serum albumin, has been measured using small volume spherical resonators at frequencies in the range 200 kHz-1.2 MHz. The principles of the technique are discussed and absorption values obtained for the electrolyte solutions at 20 degrees C are compared with existing values using other methods. For BSA, measurements were made at 8 degrees C over a range of pH values. Under both acid and alkaline conditions, excess losses at megahertz frequencies were found to persist down to at least 200 kHz. A new loss peak at approximately 400 kHz has been found at pH 3.2.

Absorption↗
PubMed1978

Wescodyne: lack of activity against poliovirus in the presence of organic matter.

The National Institute of Health Guidelines for Recombinant DNA Research recommends 2% aqueous Wescodyne, an iodophore that is used in many hospitals and laboratories as a disinfectant, as a decontaminant for biological safety cabinets and 5% for a spill outside a cabinet. A contact time of 10 to 15 minutes was given for the 2% solution and 20 minutes was considered adequate for the 5% concentration. The results indicate: 1. Aqueous Wescodyne (5%) is ineffective when used for 80 minutes against poliovirus in a test mixture containing 8.5% bovine serum albumin (a mixture equivalent in protein concentration to the higher range in serum). 2. Wescodyne (10%) employed under the same conditions for 40 minutes is also ineffective. 3. Wescodyne (10% v/v) in 50% ethanol (w/w) was effective and this mixture, originally recommended for hand washing, should be considered for use in biohazard situations, particularly for decontamination of work surfaces and biological safety cabinets. These results are of significance for if a virucide cannot inactivate poliovirus one would be concerned about using the virucide against hepatitis B or SV40 viruses.

Cells, Cultured↗