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Biomedical subjects

J T McCall

Publications and source records attributed to J T McCall.

At least 19 recordsLinked to original sources
PubMed1991

Increased urinary zinc excretion after thermal injury.

Urinary zinc excretion normally plays a minor role in zinc homeostasis; however, urinary zinc excretion is markedly elevated after trauma or surgery, and mechanism(s) for this zinc loss are poorly defined. In this study we evaluated multiple potential mechanisms for increased urinary zinc excretion in patients with thermal injury. We documented that patients with severe thermal injury had markedly elevated urinary zinc excretion. Above 20% total body surface area burn, however, the severity of thermal injury did not correlate with urinary zinc excretion. Serum zinc concentrations were depressed on initial evaluation and gradually increased during the hospital course, whereas peak urinary zinc excretion occurred 2 to 5 weeks after injury. Thus the depression in serum zinc concentration did not temporally relate to the observed pattern of hyperzincuria. Increased urinary zinc excretion also did not temporally relate to urinary excretion of the amino acids cysteine and histidine (both of which tightly bind zinc) nor to urinary 3-methylhistidine excretion, a marker of muscle breakdown. Urinary amylase excretion, a marker of renal tubular dysfunction, did follow the pattern of urinary zinc loss to some extent, although this correlation was not perfect. Increased oral intake of zinc via zinc supplements resulted in significantly increased urinary zinc excretion. Patients receiving total parenteral nutrition (TPN) did not have significantly increased urinary zinc excretion when compared with people receiving their total nutrient intake by mouth.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Serum zinc response in thermal injury.

Zinc is an essential trace element required for RNA and DNA synthesis and the function of over 200 zinc metalloenzymes. After surgery or trauma, the serum zinc concentration usually decreases. The magnitude and duration of this hypozincemia after thermal injury are unclear, as are mechanisms for this hypozincemia. In this study we evaluated, over the duration of their hospital course, serum zinc concentrations in 23 thermal injury patients. The initial mean serum zinc concentration was significantly depressed (42 +/- micrograms/dl; normal 66-110 micrograms/dl). By the second week of hospitalization, serum zinc concentrations gradually increased into the normal range in the majority of patients. Mechanisms for this hypozincemia were evaluated. Decreases in the serum zinc concentration did not correlate with increased urinary zinc excretion; thus increased urinary zinc excretion was an unlikely mechanism for the observed hypozincemia. Values for albumin, the major zinc binding protein in serum, generally were inversely correlated with the serum zinc concentration. Thus, hypoalbuminemia could not explain the decreased serum zinc concentration. Certain cytokines such as interleukin-1 are known to cause a decrease in the serum zinc concentration as part of the acute phase response. Therefore, we measured serum C reactive protein concentrations as an indicator of the acute phase response. Thermally injured patients initially had markedly elevated C-reactive protein levels which gradually decreased during hospitalization. We suggest that the initial hypozincemia observed in thermally injured patients may be a reflection of interleukin-1 mediated acute phase response. Whether one should vigorously attempt to correct this initial marked hypozincemia requires further investigation.

Adult↗
PubMed1987

Cardiac iron deposition in idiopathic hemochromatosis: histologic and analytic assessment of 14 hearts from autopsy.

In each heart taken from autopsies of 14 men with idiopathic hemochromatosis, the conduction system, atria and 10 sites in the ventricles were histologically graded for stainable iron. Stainable iron was exclusively sarcoplasmic; none was observed in the interstitium. The histologic grade for the same anatomic site varied among hearts and among different anatomic sites in the same heart. Ten hearts had stainable iron in all ventricular sites; one of the three hearts from patients who had undergone therapeutic phlebotomy had no iron at any site. Seven hearts had iron in the atria but at a lesser grade than that found in the ventricles; six hearts had mild focal iron deposition in the atrioventricular conduction system. None of the 14 hearts had stainable iron in the sinus node. Elemental iron was quantitated by atomic absorption spectroscopy in ventricular specimens contiguous to those studied histologically and also in age-matched control hearts. Elemental iron content was markedly increased in hearts with idiopathic hemochromatosis compared with control hearts (p less than 0.01). The quantity of elemental iron varied greatly, similar to stainable iron, but was highest subepicardially. Among the hearts from the 11 patients without prior phlebotomy, three had no stainable iron in the right ventricular septal subendocardium, suggesting that sampling error may be a problem in the evaluation of hemochromatosis by endomyocardial biopsy. The sarcoplasmic location of the iron indicates that cardiac involvement in idiopathic hemochromatosis represents a storage disease and not an infiltrative process; this finding is consistent with the normal ventricular wall thicknesses observed.

Adult↗
PubMed1987

Serum and urinary silver levels in thermal injury patients.

Although silver sulfadiazine has been used extensively as an effective topical antimicrobial agent in thermal injury patients, little is known about the cutaneous absorption of the silver moiety in these patients. Therefore, we longitudinally evaluated both serum silver concentration and 24-hour urinary excretion of silver in 23 patients with second- and third-degree thermal burns. Mean serum silver concentrations were modestly elevated throughout the patients' hospital course. Urinary excretion of silver was markedly elevated, especially in those patients with more severe burns. Indeed, in patients who had burns covering more than 60% of the total body surface area mean peak silver excretion was 1100 micrograms/24 hr (normal, less than 1 micrograms/24 hr). Thus, silver ion is absorbed across the burn wound in thermal injury patients treated with silver sulfadiazine. The 24-hour urinary excretion of silver appears to be a very sensitive indicator of cutaneous absorption in these patients. Possible implications of this cutaneous silver absorption warrant further evaluation.

Administration, Topical↗
PubMed1986

Serum and urinary selenium levels in thermal injury.

Information concerning selenium status in thermal injury patients is limited. Therefore, both serum selenium concentration and 24 h urinary excretion of selenium were evaluated throughout the hospital course for 23 patients with partial and full skin thickness thermal burns. Serum selenium levels were depressed throughout the hospital course in the majority of patients, and only two patients' serum selenium levels had reached the normal range by discharge. Urinary selenium losses were essentially within normal range throughout the same period and thus were not responsible for the observed depression in serum selenium levels. A possible antagonistic relationship between selenium and silver is discussed.

Adult↗
PubMed1986

Serum copper and ceruloplasmin levels and urinary copper excretion in thermal injury.

Conflicting reports regarding copper status in thermal injury patients have been published. We determined serial serum-copper and serum-ceruloplasmin levels and 24-h urinary excretion of copper in 23 patients with second- and third-degree thermal burns. Throughout hospitalization, mean serum-copper concentration was significantly depressed; lowest levels were found in patients with greater than 40% total body surface area burns. Serum ceruloplasmin was also depressed, an unexpected finding because this protein is a positive acute-phase reactant poststress. Mean urinary excretion of copper was elevated, reaching 2.5 times the upper limit of normal 2 wk postburn. Depressed serum-copper levels paralleled the serum-ceruloplasmin levels rather than the increased urinary-copper losses. Further studies are required to determine the mechanism(s) of this altered copper metabolism and whether physiological or biochemical evidence of copper deficiency accompanies the observed hypocupremia.

Adult↗
PubMed1986

Routine measurement of calcium, magnesium, copper, zinc, and iron in urine and serum by inductively coupled plasma emission spectroscopy.

We describe an inductively coupled plasma atomic emission spectrometer that has been adapted to perform routine, simultaneous, direct analyses of calcium, magnesium, copper, zinc, and iron in serum or urine without sample digestion or pretreatment. The system, constructed with inexpensive, readily available components, can analyze 1-mL or smaller samples. Results correlate nearly perfectly with those derived by standard atomic absorption techniques (r = 0.98 to 0.997). Using certified serum and urine samples from various sources, we demonstrate that the instrument yields accurate results with a precision better than certified values. The instrument is sensitive to one order of magnitude less than the lower limit of the normal range in serum or urine for all elements tested, and responds linearly to concentrations two orders of magnitude higher than the upper limit of the normal range. With the system described here, these five elements can be assayed with the same or less technical effort than needed for a single element by atomic absorption.

Autoanalysis↗
PubMed1985

Trial of penicillamine in advanced primary biliary cirrhosis.

A total of 227 patients with histologically advanced primary biliary cirrhosis entered a double-blind, randomized, controlled trial to determine whether penicillamine (1 g per day) was therapeutically effective; 111 patients received the drug, and 116 received placebo. The two groups were highly comparable at entry with regard to clinical, biochemical, and histologic features. Penicillamine therapy did not result in an overall improvement in survival as compared with placebo. Clinical symptoms and serial hepatic laboratory values reflected the progressive nature of the disease and were similar in both groups. There were no substantial differences between treatment groups in the morphologic features of sequential biopsy specimens. The development of major side effects led to permanent discontinuation of penicillamine in 22 per cent of the patients taking the drug. We conclude that penicillamine is not useful for patients with histologically advanced primary biliary cirrhosis. The trial is being continued in patients with early histologic disease whose better prognosis necessitates longer follow-up.

Clinical Trials as Topic↗
PubMed1985

Abnormalities in tests of copper metabolism in primary sclerosing cholangitis.

Primary sclerosing cholangitis is a chronic, cholestatic syndrome characterized by fibrosing inflammation of the bile ducts that may lead to cirrhosis and death from liver failure. Previous reports have suggested abnormal hepatic copper metabolism in this disease. Therefore, in 70 patients, we prospectively determined the levels of hepatic copper, serum copper, and serum ceruloplasmin, and the rate of urinary copper excretion to assess the diagnostic and prognostic usefulness of these tests. Virtually all patients had at least one abnormal copper test. Hepatic copper levels were elevated in 87% of patients [292 +/- 38 micrograms/g dry wt (mean +/- SE)] and 24-h urinary copper levels in 64% of patients [135 +/- 15 micrograms/24 h (mean +/- SE)] to values comparable to those seen in Wilson's disease or primary biliary cirrhosis. In advanced histologic stages of primary sclerosing cholangitis, progressively higher mean levels of hepatic and urinary copper were found. In the liver, mean copper content (in micrograms per gram dry weight) in disease stages I and II was 147 +/- 36 (mean +/- SE); in stage III (fibrosis), 302 +/- 68; and in stage IV (cirrhosis), 379 +/- 69. In the urine, mean copper excretion (in micrograms per 24 h) in stages I and II was 72 +/- 14 (mean +/- SE); in stage III, 100 +/- 14; and in stage IV, 207 +/- 30. Higher hepatic and urinary copper levels at initial evaluation were associated with decreased survival during a median follow-up period of 2.6 yr: patients with hepatic copper greater than 250 micrograms/g dry wt and urinary copper excretion greater than 200 micrograms/24 h at initial evaluation had an 18-mo survival of less than 60%. We conclude that abnormal copper metabolism is a universal feature of primary sclerosing cholangitis, that hepatic copper accumulates and urinary copper excretion increases as the disease progresses, and that the hepatic copper concentration and the 24-h urinary copper determination are useful prognostic indicators in this disease.

Ceruloplasmin↗
PubMed1985

Elevated bone aluminum content in dialysis patients without osteomalacia.

In almost all dialysis patients, bone aluminum content (BAC) is elevated in comparison with levels in normal subjects. Extremely high BAC (200 micrograms or more of aluminum per gram of bone) is significantly associated with classic aluminum-related osteomalacia. We noted three patients with elevated BAC but without histologic evidence of typical osteomalacia. Two of the patients had moderately severe osteitis fibrosa (hyperparathyroidism), and one patient had mixed uremic bone disease--predominantly hyperparathyroidism but some impairment of bone mineralization as well. As has recently been reported by others, the deferoxamine infusion test yielded unusual results in these patients. On the basis of our observations, we believe that an isolated measurement of BAC to determine whether aluminum-related osteomalacia is present has certain limitations. Aluminum-related bone disease can be accurately diagnosed only with use of bone histomorphometry. Elevated levels of immunoreactive parathyroid hormone may offer protection from the toxic effects of aluminum.

Adult↗
PubMed1983

Hemochromatosis: genetic or alcohol-induced?

To evaluate the roles of alcohol and genetic factors in hepatic iron overload, we studied prospectively 61 patients selected solely on the basis of increased stainable hepatic iron (grade 3 or 4). Independent comparisons were made between alcoholic (n = 20) and nonalcoholic (n = 41) patients, and between patients wih affected relatives (n = 25) and those without (n = 36). For the entire group, the mean value for mobilizable iron was 19.6 g and the prevalence of HLA-A3 was 69.6%, both findings compatible with genetic hemochromatosis. Subgroups were no different in clinical features (diabetes, pigmentation, cardiomyopathy, hypogonadism, or arthropaty), histologic findings (fat, inflammation, fibrosis), indexes of iron metabolism (serum iron, transferrin saturation, chelatable iron, and mobilizable iron stores), or frequency of HLA-A3 and HLA-B7. The only exception was that mean hepatic iron concentration was lower in alcoholic patients than in nonalcoholic patients (17,344 vs. 28,553 micrograms/g dry wt, p less than 0.001). Similarity between subgroups in almost all parameters examined is consistent with the hypothesis that heavy deposition of hepatic iron, as observed in our patients, is an indication of genetic hemochromatosis, regardless of alcohol consumption or the findings of affected relatives. The lower concentrations of hepatic iron in alcoholic patients, despite equal body stores in both groups, suggest that alcohol may alter the distribution of storage iron in genetic hemochromatosis.

Adult↗
PubMed1983

Diagnosis of Wilson's disease presenting as fulminant hepatic failure.

The clinical course, results of standard laboratory tests, parameters of copper metabolism, and hepatic morphology in 9 cases (3 of our own and 6 from the literature) of Wilson's disease presenting as fulminant hepatic failure were compared with the findings in 5 cases of idiopathic fulminant hepatic failure. Patients with Wilson's disease were usually younger, and 7 of the 9 patients had Kayser-Fleischer rings. Patients with idiopathic fulminant hepatic failure had elevated 24-h urinary copper, decreased ceruloplasmin, and low or normal serum copper. Fulminant hepatic failure with Wilson's disease differed from idiopathic fulminant hepatic failure by the following biochemical findings: (a) higher copper levels in serum, urine and liver; (b) less pronounced elevations of transaminase levels; (c) higher concentrations of total bilirubin; and (d) lower hemoglobin values. Serum copper was the most useful biochemical test in diagnosing Wilson's disease before death. At autopsy, only hepatic copper concentrations clearly separated the two groups. Serial serum copper levels (antemortem) and quantitative analysis of hepatic copper (after recovery or postmortem) in patients with fulminant hepatic failure should help to exclude Wilson's disease.

Adolescent↗
PubMed1983

Identification of the carrier of the Bedlington Terrier copper disease.

Copper (Cu) was assayed in serial liver biopsy specimens of 5 pups resulting from a mating of 2 Bedlington Terrier carriers of inherited Cu toxicosis; the latter were sibling offspring of an affected Bedlington Terrier and a normal dog. Between 5 and 7 months of age, 1 of the pups had acceptable hepatic Cu values in each of 6 specimens. The hepatic concentration of Cu in another pup increased steadily from 801 to 3,874 micrograms/g dry weight. The other 3 pups may be heterozygotes (carriers); in 1--the hepatic Cu peaked at 1,043 micrograms/g at 9 months, in the 2nd--at 636 micrograms/g at 7 months, and in the 3rd--at 492 micrograms/g at 7 months. Acceptable concentrations were present in these 3 dogs at 9 to 14 months. Results in the present study indicate that heterozygotes may have 1 normal and 1 abnormal controller gene for regulating their hepatic Cu metabolism, thus accounting for the increased hepatic Cu concentration only in the early months of life. The affected Bedlington Terrier with 2 abnormal genes was unable to suppress the progressive hepatic accumulation of Cu. Paired liver biopsy specimens obtained at 5 to 7 months and at 14 or 15 months of are might distinguish the heterozygote from the normal and the affected Bedlington Terrier pups.

Animals↗
PubMed1982

Ionic shift in cerebral ischemia.

Electrolyte and water contents were measured in gerbil brain after unilateral cerebral ischemia. Increase of Na+ and water, and decrease of K+ occurred after an ischemic period of 30 minutes. However, these abnormalities disappeared within 3 hours. When the ischemic period was extended to 3 hours, the abnormalities observed after ischemia for 30 minutes were again encountered, but more significant alterations occurred immediately after re-establishment of blood flow. In addition to more pronounced increase of Na+ and decrease of K+, Ca2+ became significantly elevated after recirculation for 15 minutes and progressively increased during recirculation for 3 hours. The steady rise of Ca2+ appears to be related to the irreversibility of cerebral ischemia.

Animals↗
PubMed1982

A comparison of copper-loading disease in Bedlington terriers and Wilson's disease in humans.

Eleven Bedlington terriers were found to have a mean hepatic copper concentration of 6,321 micrograms/g dry wt (normal, 200 micrograms/g dry wt) and renal copper concentration that was three or four times normal. Brain copper levels were normal in younger dogs, were elevated in two older dogs, and were 100 times normal in one dog that died of the disease. Increased concentrations of copper in the liver, kidney, and brain also characterize Wilson's disease. Erythrocyte survival was normal in three affected dogs, but serum glutamic-pyruvic transaminase levels were usually elevated. Unlike the hypoceruloplasminemia of patients with Wilson's disease, plasma ceruloplasmin activity was not only normal but was also slightly elevated in the terriers. Despite their normal or excessive ceruloplasmin, the Bedlington terriers could convert ionic 64Cu to radioceruloplasmin but did so only very slowly. These dogs accumulated significantly more 64Cu in their livers than normal, much like patients with Wilson's disease do before symptoms develop.

Animals↗
PubMed1982

Quantification of the fate of dietary fiber in humans by a newly developed radiolabeled fiber marker.

A radiolabeled cellulose (131I-fiber) that retains the essential physical and chemical properties of this class of fiber was developed in our laboratory. We quantified the fate of orally ingested 131I-fiber in healthy individuals by external gamma camera monitoring and fecal collections. The marker passes virtually intact through the human gastrointestinal tract with negligible release and absorption of the label in the gut. Comparison of the gastric emptying rate of 131I-fiber with that of a predominantly aqueous marker, 99mTc-diethylenetriamine pentaacetic acid (99mTc-DTPA), showed that 131I-fiber strands were evacuated more slowly than intragastric fluids. An important finding was that some 131I-fiber emptying occurred during most time periods, even before liquids were completely evacuated. This suggests that the human stomach is able to empty simultaneously liquids and fiber strands (1-15 mm in length) that are resistant to grinding by antral mechanical forces and to digestion by acid-peptic secretion. Thus, some nondigestible solids may be emptied with the bulk of a meal, although at a slower rate. 131I-Fiber may be a useful marker for quantifying gastric emptying of nondigestible solids. Further, the stability of 131I-fiber in the gut, as opposed to most other physiologic solid labels, should enable future investigation of intestinal and colonic transit of fiber, which is an important component of the human diet.

Adult↗
PubMed1982

Selenium deficiency and fatal cardiomyopathy in a patient on home parenteral nutrition.

An adult patient with chronic idiopathic intestinal pseudo-obstruction maintained on home parenteral nutrition for 6 consecutive years died from cardiomyopathy and ventricular fibrillation. Postmortem examination of the heart revealed widespread myocytolysis and replacement fibrosis similar to that seen in the selenium deficient cardiomyopathy in China (Keshan disease) and animal models. Selenium deficiency in this patient was documented with extremely low concentrations of selenium and decreased activity of the selenoprotein, glutathione peroxidase, in blood, heart, liver, and skeletal muscle. Reports of selenium deficient diets causing myocardial damage in humans and animals and the findings in our patient strongly suggest that his fatal cardiomyopathy was caused by selenium deficiency.

Adult↗