Proteolipid and human aorta calcification, in vitro.

The objective of this study was to determine whether in vitro calcification of human aorta is proteolipid dependent. Homogenates were prepared from tissue with no gross pathologic manifestations. Samples were examined for calcifiability in a metastable calcium phosphate solution before and after lipid extraction. Fractions of the extracted lipid were similarly examined. The tissue calcified before but not after lipid extraction. Calcifiability was restricted to the proteolipid portion of the lipid extract. Under the conditions employed, therefore, proteolipid is required for calcification of human aorta, in vitro.

Urinary amino acid excretion: comparison of normal individuals and patients with bladder cancer.

The excretion levels of urinary amino acids obtained from acid hydrolysates were studied by gas chromatographic analysis in 29 normal individuals and 118 patients with bladder carcinoma. Leucine and isoleucine excretion were elevated in patients with bladder carcinoma as compared with normal subjects under the same experimental condition. Mathematical computer-assisted programs developed to aid in determining clusters of amino acid variables suggested that excretion of glycine, leucine, proline, and glutamic acid in men and concentrations of valine, serine, aspartic acid, phenylalanine, and lysine in women vary according to the invasiveness of the disease. These findings suggest that measurements of urinary amino acids may provide a useful parameter for the detection and aid in the staging of bladder carcinoma.

Urinary amino acid excretion patterns in cancer of prostate.

The excretion of urinary amino acids obtained from acid hydrolysates were studied by gas chromatographic analysis in 16 normal male subjects and 48 patients with cancer of the prostate. There were no significant differences of the most commonly excreted amimo acids in normal or patient groups or between patients with different stages of the disease because of the large variances of excretion within groups as a whole. However, with few exceptions, the patient group excreted isoleucine whereas isoleucine excretion was not detected in the normal subjects under the same experimental conditions. These findings suggest that measurement of the urinary excretion of isoleucine may be a useful parameter for the early detection of prostatic cancer.

Urinary amino acid excretion in acute leukemia.

Urinary amino acid excretion was determined in 31 leukemic patients and 29 normal individuals by rapid gas chromatographic analysis of 16 amino acids as their N-acetyl-n-propyl esters. The leukemic patients were concurrently undergoing, or had recently completed, chemotherapy. It was found that aspartic acid, threonine, and serine were of significance in distinguishing between patients "on" therapy and those "off" therapy. Patients with advanced disease have the greatest aminoaciduria, although both the normal and leukemic populations have wide individual ranges. Within both populations, men excrete a greater variety and quantity of amino acids than women. It is concluded that analysis of urinary amino acids represents a history of complex metabolic events, which is potentially useful for evaluating patient response to chemotherapy in leukemia.

An improved isolation procedure for the gas chromatographic analysis of urinary polyamines.

The isolation of polyamines from urinary hydrolysates in a sufficiently pure state for subsequent analysis by gas chromatography has proved to be difficult. However, by using columns of Porapak-Q and ion-exchange resins, urinary hydrolysates are readily purified and formation of trifluoroacetyl derivatives of polyamines proceeds in high yield without carryover of artifacts in the gas chromatographic elution profile. Good yields from the trifluoroacetylation reaction are not achieved if large quantities of salts or urinary pigments are present. By obtaining the polyamine carbonates in the final stages of the method described, the trifluoroacetylation reaction yields excellent derivatives of nanogram or microgram amounts, particularly after standing over-night at room temperature. The procedure described in detail should permit routine urinary polyamine analysis where rapidity, ease of handling many samples, freedom from complications and artifacts are a consideration.