Subject excretion

The ability of the liver to act as a depot for vitamin Bi2 (B28, G13) enables us to use this vitamin as an index of proper hepatic function. Hepatic disorders lead to an increased Bi2-binding in the serum (J5, R3), suggesting that the blood assumes a greater role in the conservation of B12. We have reported that patients with liver disease excreted invariably less than 10 fig of Bi2> 8 hours after a 50-[ig intramuscular load dose of the vitamin. In contrast, normal subjects excreted 24-40 pg, i.e., 50-80% of the vitamin in the same test (B14). These results were correlated with various chemical determinations indicative of hepatic disorders (Bl). In Table 16 the clinical diagnosis and the various liver-... 

C from 1- C-2-hexanone applied to the forearms of two human volunteers was found in the breath and urine (DiVincenzo et al. 1978). In one subject, excretion was similar by both routes in the other subject, the levels were much higher (about 3 1) in the breath. Levels of radioactivity in feces were not measured. 

Hadidi et al. (1997) gave members of a family 2 mg coumarin orally and collected their urine for 8 h. One subject excreted < 0.03% of the dose as 7-hydroxy coumarin and 50% as ort/io-hydroxyphenylacetic acid, but three others excreted mainly 7-hydroxy-coumarin (> 41% of dose) and 4-10% as ort/io-hydroxyphenylacetic acid. Oscarson et al. (1998) refer to two individuals (among a population of two hundred) who were totally deficient in 7-hydroxycoumarin excretion after an oral dose of 5 mg coumarin. 

Methylmalonyl-CoA mutase is a cobalamin-linked enzyme of mitochondria that catalyzes the isomerization of methylmalonyl-CoA to succinyl-CoA. A reduction of this enzyme due to vitamin B12 deficiency will result in a metabolic block with the urinary excretion of methylmalonic acid, and the measurement of this metabolite has been used to confirm a deficiency of vitamin B12. The test has also been useful in investigating rare abnormalities of this enzyme that result in the excretion of methylmalonic acid in the presence of adequate vitamin B12. Given an oral loading dose of valine or isoleucine will increase the urinary excretion of methylmalonic acid in patients with a vitamin B12 deficiency (G4). However, Chanarin and his colleagues (CIO) found that one-quarter of their patients with pernicious anemia excreted a normal concentration of methylmalonic acid even after a loading dose of valine. Normal subjects excrete up to 15 mg of methylmalonic acid in their urine over a 24-hour period (Cll). 

The excretion of a test dose of thiamin has also been used as an index of status after a parenteral dose of 5 mg (19 /rmol) of thiamin, adequately nourished subjects excrete more than 300 nmol of the vitamin over 4 hours, whereas deficient subjects excrete less than 75 nmol. 

The absorption of vitamin B12 can be determined by the Schilling test. An oral dose of [ Co] or [ Co]vitamin B12 is given with a parenteral flushing dose of 1 mg of nonradioactive vitamin, and the urinary excretion of radioactivity is followed as an index of absorption of the oral material. Normal subjects excrete 16% to 45% of the radioactivity over 24 hours, whereas patients lacking intrinsic factor or with antiintrinsic factor antibodies excrete less than 5%. 

The fecal marker (PEG) was analyzed by the turbidimetric method of Malaware and Powell ( ). Total recoveries of ingested PEG in feces ranged from 20% to 99 7%. Three subjects excreted less than 60% of the ingested PEG, whereas the rest had an average recovery of 85.3% (range 73%-99.7%). 

According to all authors, normal subjects excrete only a few mg daily of the more important tryptophan metabolites. 

Gershoff and Prien (G6) found that normal subjects excrete significantly less xanthurenic acid and 4-pyridoxic acid and more citric acid than patients with chronic formation of calcium oxalate. A marked rise in excretion of calcium oxalate followed administration of tryptophan in these patients, whereas ingestion of pyridoxine was followed by a decrease in urinary oxalate. 

In a cross-sectional study by Boujemaa et al. [67], who evaluated early indicators of renal dysfunction in silicotic workers (n=116), recorded a delay after cessation of exposure up to 30 years (mean 23 years). The silicotic subjects excreted, on average, slightly higher amounts of albumin, retinol binding protein and N-acetyl-P-D-glucosaminidase [66, 67, 69]. 

Silicic acid is readily absorbed, and plasma levels rise rapidly following intake. In normal subjects excretion is rapid, average plasma levels are 5-10 pM, and all cells and tissues contain silicon, which may be concentrated in some cells or cellular compartments, for example, in the osteoblast. Little is known of the interactions between this silicic acid and internalized aluminum. With aluminum bound strongly to transferrin and the low plasma silicic acid levels, interaction is unlikely except at sites of local concentration. Codeposited aluminum and silicon (as amorphous aluminosilicate) has, so far as is known, been reported only at the core of senile plaques. Separate groups of workers report silicon in artery walls (44) and aluminum (45) in artery walls, but no studies have been made of the association and balance of the two elements in tissue. Such studies will be required if progress is to be made. Some workers have reported an... 

Urinary excretion during the first 6 hr. accounted for 29-74 % of the injected morphine, and for 56-91 % at 24 hr. (see Table 5). Three of the 5 subjects excreted 5-7 % during the 2nd day and all excreted small amounts the 3rd day. The addict excreted morphine at the most rapid rate and had the greatest urine output. Nontolerant subjects excreted 7-10% of the dose in the feces in 3-4 days. In contrast, the feces of the addict contained only a negligible amount of radioactivity. 

All subjects excreted 4-6% of injected radioactivity in the expired air during the first 24 hr. This was in contrast to rats where the females excreted very little C by this route. In man the peak rate of respiratory excretion was during the 2nd hr., and fell to low levels at 6-8 hrs. However, measurable levels of radioactivity were present in the expired air of 2 subjects for 4-5 days. 

Silicic acid is readily absorbed, and plasma levels rise rapidly following intake. In normal subjects excretion is... 

Castration and testosterone replacement significantly influenced the concentrations of Imwe and Peak 2 esterase in the urine from SWR males (Table 2). All ten subjects excreted both esterases prior to castration and after testosterone replacement, but only three males did so two weeks after castration. While concentrations of these two esterases did not differ from each other prior to or following castration, Imwe concentrations were significantly greater than Peak 2 concentrations following testosterone replacement. 

Normal fasting adult subjects excrete 250 to 500 mg of phenyl-acetylglutamine per day [29]. Amounts are Increased following ingestion of phenylacetic acid [41] and in patients with phenylketonuria who produce increased quantities of phenylacetic acid [29] The reactions concerned have been defined by Moldave and Melster [42] in human liver mitochondria ... 

Pyridoxine deficiency has been induced by administration of desoxy-pyridoxine to adults receiving a diet low in B complex vitamins. Seborrheic skin lesions developed about the eyes, nose, and mouth, and cheilosis, glossitis, and stomatitis were observed. Although these findings resemble those commonly seen in riboflavin and niacin deficiency, healing was dependent on administration of pyridoxine. The deficient subjects excreted large amounts of xanthurenic acid in the urine after a test dose of tryptophan, but ability to convert tryptophan to niacin was unimpaired. 

Colorectal cancer subjects excrete higher concentrations of fecal bile acids[19,57] and carry more organisms able to dehydrogenate these substrates[59]. Although the correlation has not been confirmed in all studies[62,63] this may be due to some patient groups containing a disproportionate number of advanced and metastasized tumors. These conditions may be associated with impaired liver function and bile acid secretion, and is supported by the observation that subjects with Dukes C cancer excrete significantly lower concen-... 

Acid Concentration range (mg per g of creatinine ) Number of subjects excreting detectable amounts... 

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