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Biomedical subjects

J L White

Publications and source records attributed to J L White.

At least 19 recordsLinked to original sources

Direct angioplasty versus initial thrombolytic therapy for acute myocardial infarction: long-term follow-up and changes in practice pattern.

We retrospectively studied the outcomes of patients with acute myocardial infarction who were treated with either direct angioplasty or thrombolytics followed by angioplasty. Two patient cohorts were analyzed: a previously reported (in regard to short-term follow-up) group of 371 patients who now have long-term follow-up (mean, 3.4 years) of survival and event-free survival and a second group of 202 patients who have been treated since publication of our initial data. Both 1-year and 2-year survival were significantly better (p = 0.01 and 0.02, respectively) in the group that was treated with thrombolytics first. Event-free survival (i.e., no myocardial infarction, coronary artery bypass graft surgery, repeat angioplasty) was better overall (p < 0.01) for the group that was treated with thrombolytics first. The more recently treated group of patients also showed benefit in regard to both survival (p = 0.002) and event-free survival (p < 0.01) over a short-term follow-up period (mean, 39 weeks) for patients who were treated initially with thrombolytics as compared with those who were treated with direct angioplasty. Although the initial cohort was very similar to the treatment groups except for age (mean age for the direct angioplasty group was 62 +/- 12 years vs 57 +/- 11 years for thrombolytics first group, (p = 0.0002), several differences existed in the more recent treatment groups. The patients who were more recently treated with direct angioplasty were older, had lower mean ejection fraction, had more extensive coronary artery disease, and were more likely to have had prior coronary artery bypass grafting.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged

Contribution of soluble aluminium species to absorption of aluminium from the rat gut in situ.

1. Rat gut perfusion studies in vivo at pH 4, 6 or 8 using aluminium chloride or equimolar aluminium chloride and sodium citrate showed that elevated plasma aluminium concentrations were associated with aluminium solubility in the perfusion. Elevated plasma aluminium levels and soluble aluminium in the perfusate occurred with perfusion of equimolar aluminium chloride and sodium citrate at all three pH values. 2. Partitioning studies in vitro, utilizing water and ethyl acetate, revealed that uncomplexed aluminium exhibited maximum partitioning into the ethyl acetate phase at pH 2.5. When complexed with citrate, aluminium exhibited partitioning over a much broader pH range, pH 2.5-8.0. 3. A direct linear relationship was observed between the soluble aluminium concentration of the perfusate and the increase in the plasma aluminium level, suggesting that soluble aluminium is absorbed by a passive diffusion mechanism.

Aluminum

The location of exon boundaries in the multimeric iron-storage protein ferritin.

The nature of the amino acids whose codons border introns in ferritin genes is novel; the disposition of these intron boundaries within the three-dimensional structure of the 24-subunit molecule differs significantly from that of other proteins. These observations are discussed in relation to the functions of isoferritins.

Amino Acid Sequence

Predicting the adsorption of proteins by aluminium-containing adjuvants.

The adsorption of two model proteins, albumin and lysozyme, by boehmite or amorphous aluminium hydroxyphosphate adjuvants was studied. Electrostatic, attraction has a major role in adsorption. At physiological pH, boehmite, which has a point of zero charge above 7.35, extensively adsorbed albumin, which has an isoelectric point of 4.8, but was not effective in adsorbing lysozyme (isoelectric point, 11.0). Conversely, amorphous aluminium hydroxyphosphate (point of zero charge, 4.0) was effective in adsorbing lysozyme but adsorbed relatively little albumin. The results suggest that the selection of either boehmite or amorphous aluminium hydroxyphosphate as an adjuvant should be based in part on the isoelectric point of the antigen.

Adjuvants, Immunologic

Effect of competing anions on binding of bile salts by cholestyramine.

The binding of bile salts by cholestyramine may be influenced by other anions, as the Langmuir adsorption coefficients for three bile salts tested were similar to the model anion, citrate. However, the selectivity coefficient indicated preferential binding of cholate anion in comparison to citrate anion. Binding experiments confirmed cholestyramine's preference for bile salts as the presence of other anions reduced but did not prevent the binding of cholate anion. Binding of cholate anion was reduced in direct relationship to the citrate anion concentration. Prior exposure of cholestyramine to citrate anion caused the binding of cholate anion to decrease slightly. Sequential exposure of cholestyramine to simulated gastric fluid and simulated intestinal fluid containing cholate anion resulted in a decrease in cholate binding which was attributed to competition with anions present in the gastrointestinal fluids. Components of tomato juice and orange juice, fluids, commonly used to enhance ingestion of cholestyramine, also reduced the binding of cholate anion.

Adsorption

Aluminum compounds used as adjuvants in vaccines.

The structure of nine commercially manufactured aluminum-containing adjuvants was investigated by X-ray diffraction, infrared spectroscopy, transmission electron micrography, and energy dispersive spectrometry. Seven samples which were labeled as aluminum hydroxide were identified as boehmite, a crystalline aluminum oxyhydroxide [AlO(OH)]. However, the degree of crystallinity varied between the samples. Two samples which were labeled as aluminum phosphate were found to be amorphous aluminum hydroxyphosphate. Buffer anions and sulfate anions substitute for hydroxyls in the amorphous aluminum hydroxide formed by the in situ alum precipitation method. Finally, the aluminum-containing adjuvant in diphtheria and tetanus toxoid, U.S.P., produced by three manufacturers was characterized.

Adjuvants, Pharmaceutic

A simple method for detection of viral satellite RNAs in small plant tissue samples.

A procedure is described that allows extraction and can estimate the total amount of single-stranded and double-stranded viral satellite RNAs and viral RNA present in a minimal amount of infected plant tissue, and is capable of distinguishing different cucumber mosaic viral and nepoviral satellites by polyacrylamide gel electrophoresis under semi-denaturing or fully-denaturing conditions.

Blotting, Northern

In vitro adsorption of bile salts by colestipol hydrochloride.

The acid-base titration of colestipol hydrochloride exhibits no sharp inflection points, indicating a weakly basic anion-exchange copolymer. The swelling of colestipol hydrochloride in water and the adsorption of cholate anion are inversely related to pH and are, therefore, related to the ionization state of the copolymer. The Langmuir adsorption parameters at pH 7.5 and 37 degrees C are similar for cholate, glycocholate, and taurocholate anions. Adsorption capacity was not related to particle size and exceeded the adsorptive capacity of the external surface by three orders of magnitude. Therefore, it is believed that the swelling of colestipol hydrochloride makes extensive internal surface area available for adsorption of bile salts. The rate of adsorption depends on the concentration of sodium cholate to which the colestipol hydrochloride is exposed. Adsorption was complete within 5 min when the concentration was below the adsorptive capacity. In contrast, adsorption at levels of sodium cholate at or above the adsorptive capacity was not complete within a 3-hr test period.

Adsorption

Effect of anions on adsorption of bile salts by colestipol hydrochloride.

The Langmuir affinity constant and adsorptive capacity for the adsorption of citrate anion or cholate anion by colestipol hydrochloride at pH 7.5, 37 degrees C, were similar. Prior exposure of colestipol hydrochloride to citrate anion caused the adsorption of cholate anion to decrease slightly in comparison to a control utilizing only cholate anion. The concentration of citrate anion was found to be directly related to the decrease in cholate anion adsorption. Simultaneous exposure of colestipol hydrochloride to citrate and cholate anions at pH 7.5, 37 degrees C, resulted in the same adsorption of cholate anion as sequential exposure to citrate anion followed by cholate anion. Sequential exposure of colestipol hydrochloride to simulated gastric fluid and simulated intestinal fluid containing cholate anion resulted in a small decrease in cholate adsorption which was attributed to competition with phosphate anion in simulated intestinal fluid. Pepsin in the simulated gastric fluid did not affect adsorption of cholate anion from simulated intestinal fluid. Preexposure to components of tomato juice and orange juice also slightly reduced the adsorption of cholate anion by colestipol hydrochloride.

Adsorption

A prospective replication of the protective effects of IQ in subjects at high risk for juvenile delinquency.

The purpose of the study was to test the replicability of a protective effect of high IQ against criminality. Support has been found in prior studies for the hypotheses that Ss at high risk would have an elevated risk of serious criminal involvement, that seriously criminal Ss would have a lower mean IQ score than noncriminal Ss, and that Ss at high risk who had not become involved in serious criminal behavior would have the highest IQs. This report tests these hypotheses in a prospective design. Subjects were 1,037 members of a longitudinal investigation of a New Zealand birth cohort. IQs were examined for male and female Ss who were divided into 4 groups formed on the basis of risk status at age 5 years and delinquency outcome at ages 13 and 15. Analyses were conducted with and without mild delinquents excluded from the nondelinquent groups. We found that male and female delinquents showed significantly lower IQ scores than nondelinquents. By varying S selection procedures, we also found that a very high IQ may help boys, even those at risk, to stay free of delinquency altogether.

Child, Preschool

Interlocked intramedullary nailing of the humerus.

Indications for use of the intramedullary interlocked humeral nail are: pathologic fractures, including those with severe osteopenia alone; nonunions, especially those with bone atrophy and/or marked osteopenia; and humeral shaft fractures with comminution, bone loss, or other causes of instability not controlled by conventional treatment methods. In this series, eight patients were treated by intramedullary interlocked humeral nail. Follow up ranged up to 30 months, with an average of 12 months. Five of six patients in this series who had the potential to unite their fractures did so. The remaining patient had a painless fibrous union. While the two patients with pathologic fractures of the humeral shaft caused by malignant tumors did not unite their fractures, the pain relief, functional recovery, and lack of postoperative morbidity justified the operative procedure.

Adult

A European study of views on the use of monoamine oxidase inhibitors.

A total of 1269 psychiatrists, from 15 European countries, completed a questionnaire assessing treatment choice in depressive and anxiety disorders, with particular focus on diagnostic and other factors determining use of monoamine oxidase inhibitors (MAOIs). Tricyclic and similar antidepressants were used most commonly--MAOIs were used as first-choice therapy for depressive or anxiety disorders only by a minority but were commonly a second-choice treatment for atypical depressives. Use was inhibited by interactions and side-effects rather than by perceived ineffectiveness. Cross-national differences in treatment were considerable but diagnostic differences in case history vignettes were much smaller.

Adjustment Disorders

Validation of fiber-optic Doppler anemometry (FODA) for characterizing the droplet size of emulsions.

Fiber-optic Doppler anemometry (FODA) is a useful tool to characterize polydisperse systems such as emulsions. The mean droplet radius of a model emulsion determined by FODA matched the mean radius determined by sizing droplets from a freeze-fractured freeze-etched scanning electron photomicrograph. The mean droplet radius determined by the Coulter technique was four times too large because the small droplets were not detected. The utility of FODA was further illustrated by its ability to accurately size droplets and monitor the coalescence upon aging of an intravenous lipid emulsion.

Emulsions