Horace H. Zinneman

The association of giardiasis with reduced intestinal secretory immunoglobulin A

Patients with dysgammaglobulinemia frequently harborGiardia lamblia in the upper intestinal tract. However, in patients with symptomatic giardiasis serum immunoglobulin deficiencies have not been a constant or prevailing finding. Immunoglobulin level in duodenal aspirates from 10 patients with chronic symptomatic giardiasis and 10 control subjects were examined under controlled conditions, 3 to 9 months afterGiardia lamblia were eradicated with quinacrine and intestinal morphology and function were presumably fully recovered. Serum immunoglobulin concentrations in 10 patients with symptomatic giardiasis were within the normal range. In contrast, secretory IgA of the aspirates from the duodenojejunal junction of these patients was significantly lower (mean, 52.4 mg/100ml) than that obtained from aspirates of the 10 control subjects under identical conditions (mean, 162.3 mg/100ml) (P<0.01). The results indicate that the function of secretory immunoglobulins can be dissociated from serum immunoglobulins, and that decreased concentrations of secretory IgA predisposed our patients to colonization of intestinal mucous membranes byG lamblia with subsequent chronic diarrhea.

Effect of Endogenous Insulin on Human Amino Acid Metabolism

This study describes the effect of endogenous insulin on free plasma amino acids. The secretion of insulin was provoked by means of a standard glucose tolerance test. Four healthy males responded by a drop in the levels of all twenty-two plasma amino acids, which were measured. In four insulin-dependent diabetics the glucose tolerance experiment effected only slight decreases in nineteen of twenty-two amino acids. Ornithine and histidine decreased significantly, whereas phenylalanine increased. The over-all result indicates that endogenous insulin reduces the levels of the majority, if not all, free plasma amino acids.

Plasma and urinary amino acids in laennec's cirrhosis

Plasma amino acid concentrations and urinary excretion of free amino acids were measured in 7 patients with severe hepatic decompensation (precoma) in Laennecs cirrhosis. Upon maximal improvement these patients served as their own controls. Contrary to earlier reports, the changes were found to be unspectacular. Plasma concentrations of amino acids proved to be remarkably stable. Decreased plasma concentrations of valine, leucine, and isoleucine pointed to a component of steatonecrosis, which was found in liver biopsy specimens and laboratory parameters. The urinary excretion of threonine, serine, asparagine/glutamine, alanine, ethanolamine, and histidine was increased significantly during hepatic decompensation when compared to the excretion values of the same patients at maximal compensation; but even here the changes were within the normal range. General aminoaciduria was observed in 3 cirrhotic patients who had undergone surgical portacaval shunts. It is possible that these changes are a sequence of the surgical procedure.

Evaluation of Three Newer Methods for Investigating Protein Interactions of Penicillin G

The interaction of penicillin G with human serum proteins was evaluated by three different techniques: rate of dialysis, cross-linked dextran exclusion, and ultracentrifugation. The rate-of-dialysis technique demonstrated that penicillin G binding to serum was immediate but incompletely reversible. Cross-linked dextran adsorbed or trapped significant amounts of penicillin G, necessitating correction factors of more than 10%. Ultracentrifugation was found to be the most reliable method for quantitative protein-binding determinations of penicillins.

Some biochemical properties of a cryomacroglobulin

Abstract Cryoglobulin McE precipitated below 30° in the pH range of 5 to 10.5. Immunoelectrophoresis and ultracentrifugation showed it to be an IgMK which aggregated to 24 S and 35 S at pH 7.0. Cryoprecipitation was abolished by disulfide reduction and 6 M urea, both reversible by removal of the agents. Sodium dodecyl sulfate abolished cryoprecipitation irreversibly but not the tendency to aggregate. The carbohydrate content of IgMK (McE) was normal. Amino acid analysis showed low tyrosine (28 moles) and methionine (6 moles) per IgMK (McE) subunit. l -chains were found to have normal anino acid composition, but H-chains had only 6 moles of tyrosine and 3 moles of methionine and tended to form aggregates of 13 S. Nitration with TNM showed that IgMK (McE) had 13 moles of tyrosine per subunit in exposed position, compared to 9 moles in the nitration of normal IgMs, although its total tyrosine content was only 28 moles per subunit, compared to 39 of normal IgMs. These findings are compatible with a deletion in the hypervariable region of the H-chain between residues of 100 and 113.

Cryoglobulins and Pyroglobulins

A heterogeneous group of immunoglobulins (Ig’s), each member of which exhibits a temperature-dependent solubility abnormality, are known as cryoglobulins. A single Ig with the property of reversible cryoprecipitation is usually monoclonal. More frequently, two Ig’s combine by noncovalent bonds to form a mixed cryoglobulin, but when separated, neither is a cryoglobulin by itself. Cryoglobulins are usually found in blood serum, but occasionally may appear in body fluids and urine.

Dietary Methionine and Its Influence on Cystine Excretion in Cystinuric Patients

Abstract The intake of methionine containing foods was restricted in 1 cystinuric patient. L-methionine was administered to 3 other cystinuric patients in amounts of 1 Gm. daily. Neither experiment influenced the urinary excretion of cystine to an appreciable extent. The results of this study suggest that the dietary restriction of methionine is of doubtful merit in the management of cystinuric patients.