PubMed HealthSearch

Biomedical subjects

A Fleck

Publications and source records attributed to A Fleck.

At least 19 recordsLinked to original sources

Serum albumin distribution in early treated anorexia nervosa.

We investigated the effects of malnutrition and refeeding on albumin distribution and metabolism in patients undergoing treatment for anorexia nervosa. Using autologous 125I-labelled albumin, we measured the fractional catabolic rate and calculated the relative sizes of the plasma and extravascular albumin pools in 6 female anorexia nervosa subjects and 6 matched controls. We were unable to demonstrate any differences in either the catabolic rate of albumin (fractional or absolute) or in serum albumin concentration between anorexia nervosa and control subjects. There was a large expansion of the extravascular albumin pool in the anorexia nervosa subjects--36% when expressed in relation to body weight. We conclude that, at the time of study, there were no effects of anorexia nervosa on albumin catabolism in these subjects. However, the condition and its treatment are associated with a significant relative expansion of the extravascular albumin pool. This contrasts to some extent with previous work, which suggested that in protein depletion the plasma albumin pool is maintained at the expense of the extravascular albumin pool. The expansion of the extravascular albumin pool is possibly related to the relative excess of interstitial fluid seen in starvation and in the initial phases of refeeding.

Adult

Development of an enzyme-linked immunosorbent assay for human metallothionein-1 in plasma and urine.

The development of a sensitive enzyme-linked immunosorbent assay (ELISA) for human metallothionein-1 is reported. Metallothionein was purified from postmortem human liver and used to raise high-titer antibodies in rabbits. The assay was specific for human metallothionein-1 (MT-1), and there was no significant cross-reaction with human metallothionein-2. The detection limit (sensitivity) of the assay was 5 ng/ml, and the added MT-1 could be fully recovered from plasma and urine. The normal reference range for MT-1 was 32 +/- 16 ng/ml in plasma and 10 +/- 6 ng MT-1 per micromole of creatinine in random samples of urine. No significant differences were found between the values for males and females. The concentration of MT-1 was greatly increased between 24 and 48 hours after surgery, indicating that the protein behaves like an acute phase reactant in human subjects.

Acute-Phase Proteins

The effects of experimental malnutrition on albumin metabolism and distribution in rabbits.

In order to determine the extent to which the concentration of albumin in plasma is maintained at the expense of the extravascular pool during protein-energy malnutrition, the rates of exchange between albumin in plasma (IA) and the extravascular pool (EA) and consequently the distribution of albumin between intravascular and extravascular pools (expressed as EA:IA) were measured in protein-energy-depleted and control rabbits. The fractional rates of synthesis (FSR) and catabolism (FCR), the concentration of albumin and the plasma volume (PV) were also measured. In animals in which protein-energy intake was reduced by 58% the concentration of albumin in plasma remained unchanged, whereas FCR decreased by 38% and FSR by 30%. No significant changes in EA:IA or PV were found. We conclude that albumin concentration during protein-energy depletion is not maintained at the expense of extravascular albumin, but by parallel changes in the rates of catabolism and synthesis.

Algorithms

The regulatory role of external cations on human polymorphonuclear phagocyte chemiluminescence.

The effect of the external cations Na+ and Ca2+ on polymorphonuclear chemiluminescence was investigated. Both Ca2+ in the range of 0.2-2 mM and Na+ in the range of 114-143 mM showed a dose dependent increase in polymorphonuclear chemiluminescence, irrespective of the concurrent increase in osmolality. The Na+/H+ antiport inhibitor Amiloride decreased the response significantly. These effects were observed using buffers commonly used for chemiluminescence studies and indicate the importance of defining the Ca2+ and Na+ composition of the buffers used in chemiluminescence assays.

Amiloride

Clinical and nutritional aspects of changes in acute-phase proteins during inflammation.

1. When assessing the significance of altered plasma protein concentrations the various physiological factors, including posture and hormones which affect the amount and distribution of fluid in the body and the synthesis and catabolism of plasma proteins, must be kept in mind. 2. Although several cytokines, including IL-1 and TNF, are implicated in the acute-phase response, recent evidence is that the synthesis of the major acute-phase proteins (e.g. CRP) is induced by IL-6. 3. The positive acute-phase plasma proteins are useful non-specific indicators of tissue damage. 4. When there is evidence of an acute-phase response (e.g. increased CRP), decreased concentrations of plasma proteins such as albumin, transferrin, retinol-binding protein and pre-albumin cannot be assumed to reflect malnutrition. 5. Plasma albumin concentration can be a good indicator of prognosis.

Acute-Phase Proteins

Observations on the delay in onset of the acute phase protein response.

The early time course of the acute phase protein response (APPR) and mediators involved in its control were investigated in the rat and mouse. After turpentine-induced inflammation in the rat C-reactive protein and fibrinogen increased in concentration peaking at 48 h and 18-24 h, respectively. A 9 h delay prior to elevation of these protein was observed. After injection of endotoxin into mice, a 4-6 h delay was observed prior to any increase in the concentration of the acute phase protein serum amyloid P-component. This delay was shortened to 2 h after injection of leucocytic endogenous mediators (LEM) produced from rabbit peritoneal exudate cells. It is concluded that the delay between the initiating stimulus and the increases in the acute phase proteins is due to some obligatory intermediate steps which lead to the production of the final mediators of the APPR, and that these mediators are present in LEM.

Acute-Phase Reaction

Pocket computers: a new aid to nutritional support.

A program has been written to run on a pocket computer (Sharp PC-1500) that can be used at the bedside to predict the nutritional requirements of patients with a wide range of clinical conditions. The predictions of the program showed good correlation with measured values for energy and nitrogen requirements. The program was used, with good results, in the management of over 100 patients needing nutritional support. The calculation of nutritional requirements for each patient individually facilitates more appropriate treatment and may also produce financial savings when compared with administration of a standard feeding regimen to all patients.

Adolescent