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Biomedical subjects

C Lapp

Publications and source records attributed to C Lapp.

7 recordsLinked to original sources

Degree of agreement in plasma fibrinogen among two functional and one immunonephelometric assays.

The purpose of this study was to assess the interchangeability of the nephelometric (immunoassay), von Clauss, and optical (derived) fibrinogen assays. When the nephelometric assay was compared with either of the two functional assays (199 samples) and when the von Clauss and optical methods were compared (879 samples), Pearson and intraclass correlations were .96 to .97. However, there were statistically significant biases (P < .001); the mean ratios of nephelometric to functional assay values were 1.05 to 1.07, and the mean optical to von Clauss assay ratio was 1.05 (data analyzed as logs and expressed as antilogs). The 95% limits of agreement demonstrated that 5% of the ratios for the von Clauss and optical methods were outside the 0.83 to 1.32 range. Analyses restricted to cases with a fibrinogen value of less than 2.0 g/L resulted in somewhat greater biases and higher upper limits of agreement. Laboratorians need more than correlations to make informed judgments regarding the interchangeability of these methods.

Fibrinogen

Cerebrospinal fluid plasminogen activator inhibitor-1: a prognostic factor in posthaemorrhagic hydrocephalus.

Intraventricular fibrinolytic enhancement with plasminogen activators is an experimental treatment for posthaemorrhagic hydrocephalus, but some infants do not respond. The objectives of this study were to investigate whether plasminogen activator inhibitor-1 is detectable in normal or posthaemorrhagic neonatal cerebrospinal fluid and whether higher neonatal cerebrospinal fluid concentrations of plasminogen activator inhibitor-1 are associated with failure of fibrinolytic therapy. Cerebrospinal fluid samples from 7 controls and 16 infants with posthaemorrhagic hydrocephalus (15 treated with exogenous fibrinolytic agents) were analysed for plasminogen activator inhibitor-1. Plasminogen activator inhibitor-1 was not detectable in any of the control samples but was detectable in all but one of the posthaemorrhagic samples, and at significantly higher levels in the treatment failures (median 94 ng ml(-1)) than in the treatment successes (median 25 ng ml(-1)). High levels of plasminogen activator inhibitor-1 in the cerebrospinal fluid are predictive of, and provide a plausible biological explanation for, failure of intraventricular fibrinolytic therapy.

Brain Damage, Chronic

T-kininogen, processing and functions.

Studies are presented which indicate that T-kininogen, the acute phase kininogen of the rat, could be a healing protein because of its properties as a cysteine protease inhibitor. Evidence is also presented that mRNA of T-kininogen synthesis may be a function of interleukin 6 production. A regulatory mechanism is postulated by which SH cofactors could determine if T-kinin is released or whether the T-kininogen molecule would remain intact. Evidence is also presented that T-kinin acts through kinin B2 receptors. No specific binding of bradykinin or T-kinin could be detected in rat heart preparations.

Acute-Phase Proteins

Isozymes of aldolase.

A new method of starch-gel electrophoresis using a technique of staining dependent on enzyme activity has been employed to demonstrate the isozymes of aldolase from a variety of human, rat, and frog tissues. Five of these isozymes were detected in man, seven in the rat, and at least four in the frog. The abilities of these isozymes to cleave fructose-1 ,6-diphosphate and fructose-1-phosphate were compared.

Animals

Influence of hexacyanoferrate(II) based treatments upon the elimination of heavy metal traces in wine. I. The case of lead.

An investigation was undertaken to determine whether the wine treatments for elimination of iron and copper used in Western Europe--with tetrapotassium hexacyanoferrate(II): K4[Fe(CN)6]--and in the United States--with iron(II) and potassium hexacyanoferrate(II) ('Fessler compound')--are suitable for lowering the concentration of lead to within legal limits. In both series of experiments the decrease in lead concentrations remained very poor. It was concluded that the treatments using hexacyanoferrates lowered lead levels but not sufficiently to reduce completely lead contamination in wines.

Ferrocyanides