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Biomedical subjects

W K Schubert

Publications and source records attributed to W K Schubert.

At least 19 recordsLinked to original sources
PubMed1984

Grade I Reye's syndrome--outcome and predictors of progression to deeper coma grades.

We studied 83 biopsy-proved cases of Grade I Reye's syndrome to determine the outcome, possible clinical or laboratory predictors of progression to deeper coma grades, and hepatic ultrastructural findings. Seventy-eight patients had no change in coma grade during hospitalization, whereas five (6 per cent) had progression to deeper coma grades. All the patients survived without sequelae except one who sustained severe brain damage. The mean (+/- S.E.) level of serum ammonia on admission was significantly higher (P = 0.005) in patients whose disease progressed to deeper neurologic grades (291 +/- 42 micrograms per deciliter) than in those whose disease did not so progress (53 +/- 5 micrograms per deciliter), and the corrected prothrombin time was significantly more prolonged (P = 0.005) in patients with progressing coma (3.9 +/- 0.5 seconds) than in those whose coma grade did not change (1.6 +/- 0.2 seconds). The combination of a prothrombin time 3 seconds or longer than that of the control and a serum level of ammonia on admission of 100 micrograms per deciliter or more correctly predicted progression in 71.5 per cent of the cases (sensitivity, 100 per cent; specificity, 97.6 per cent). Our findings suggest that the prognosis is excellent for survival without sequelae in Grade I Reye's syndrome (98.8 per cent) when management includes hospital surveillance and intravenous glucose and electrolyte infusion.

Ammonia↗
PubMed1984

Cholesterol ester storage disease and mesenteric lipodystrophy.

Cholesterol ester storage disease is a rare, inherited metabolic disorder of lipid associated with acid cholesteryl ester hydrolase deficiency. Thus far, 15 cases have been reported in the world literature. Reported here is the autopsy study of the oldest patient with this disease. The lipid storage occurred in the forms of birefringent needle-shaped crystals limited to hepatocytes and non-birefringent autofluorescent granules accumulated within the foam cells of the hepatic portal triads, duodenum, and ovaries. The cholesterol content of the liver was 16 times normal, primarily caused by increased cholesterol ester. Only trace cholesteryl ester hydrolase activity was demonstrated in the liver. An additional unique finding in our case was the presence of mesenteric lipodystrophy. Whether these two rare disorders observed in our patient represent unrelated conditions or have an etiologic association remains unknown.

Acid Phosphatase↗
PubMed1983

Hypocalcemia and steatorrhea--clues to etiology.

Two boys with idiopathic hypoparathyroidism had extensive studies of gastrointestinal function during hypocalcemia accompanied by steatorrhea. No evidence of generalized gastrointestinal moniliasis or abnormal mucosal structure or function was observed. Studies of pancreatic function and bile salt metabolism during hypocalcemia demonstrated deficient meal-stimulated intraluminal pancreatic enzyme concentrations in both subjects and reduced bile salt concentrations in one subject. However, following stimulation with exogenous octapeptide of cholecystokinin, intraluminal pancreatic enzyme and bile salt concentrations were normal in both. Cholic acid pool sizes were markedly increased in both subjects during hypocalcemia (9 and 12 times larger than during normocalcemia) and cholic acid turnover was reduced during hypocalcemia in one subject. Our findings suggest that during hypocalcemia, insufficient endogenous cholecystokinin is released by the duodenal mucosa during a meal stimulus to stimulate normal gallbladder contraction and pancreatic enzyme secretion.

Adolescent↗
PubMed1982

Serum salicylate concentrations in Reye's disease. A study of 130 biopsy-proven cases.

Serum salicylate concentration was measured at admission in 130 children with liver-biopsy-confirmed Reye's disease. Mean serum salicylate was 12.3 mg/dl and mean salicylate concentrations by neurological grade (Lovejoy) were: stage I, 12, stage II, 13, stage III, 11, stage IV, 13, and stage V, 13 mg/dl. However, mean serum salicylate (15 mg/dl) at admission in 21 patients who died or had serious neurological deficits was significantly higher than that in 103 patients who survived without neurological sequelae (10 mg/dl). Serum salicylate in a group of 27 age-matched, community-matched control children collected consecutively over the period 1978-80 was less than 2 mg/dl, and children with varicella or influenza had salicylate concentrations indistinguishable from apparently well classmates or siblings. It is impossible to determine from this data whether salicylates are involved in the aetiology of or in determining the outcome of Reye's disease. Increased concentrations of salicylates at admission could be the result of excessive dosage because of a greater severity of the prodromal illness, or to diminished excretion because of impaired hepatic metabolism. It seems likely that serum salicylate concentrations entered the toxic range in many patients with Reye's disease before they presented for treatment. Most had been vomiting and had diminished oral intake for 33-55 h before hospital admission. Since the average number of hours from the beginning of vomiting to admission was no different in non-comatose and comatose cases, the time at which salicylate concentration was measured in relation to the last dose was probably similar in the two groups and therefore does not account for the higher levels in children with poor outcome. Salicylates are mitochondrial toxins and mitochondria are known to be significantly injured in Reye's disease; therefore, it seems wise to avoid the use of aspirin in children during outbreaks of Reye's disease.

Biopsy↗
PubMed1982

Diagnosis of phenylalanine hydroxylase deficiency (phenylketonuria).

Needle liver biopsies were carried out on patients with phenylketonuria (PKU) to establish a diagnosis either of partial or complete phenylalanine hydroxylase (PH) deficiency. Ten phenylketonuric patients and two parents were studied. Nine of the ten patients had completed a three-day oral phenylalanine challenge. Each met the accepted criteria as having classic PKU, based on a sustained rise in the serum phenylalanine level greater than 20 mg/dL. A diagnosis of classic PKU was confirmed in six patients by the absence of hepatic PH activity. Four of the PKU patients had PH activity ranging from 9% to 24% of that found in liver from non-PKU control subjects. The two parents had 27% and 42% of the PH activity found in the control subjects; their child had no activity. Current methods for distinguishing partial from complete PH deficiency are not always reliable, and the degree of the deficiency can best be established by direct measurement of the enzyme in liver.

Biopsy, Needle↗
PubMed1982

Primary bile acid malabsorption: defective in vitro ileal active bile acid transport.

Two boys with congenital diarrhea, steatorrhea, and growth failure were studied. Preliminary investigations indicated that the enterohepatic circulation of bile acids was interrupted. Radiographically, ileal structure was normal; ileal function was normal when assessed by vitamin B12 absorption. To confirm our clinical suspicion that the patients had an isolated defect of ileal active bile acid transport, peroral terminal ileal biopsies were performed. Ileal mucosa was incubated in vitro in oxygenated Krebs-Ringer bicarbonate buffer containing 10 mM glucose and 0.1, 1.0, or 10.0 mM taurocholic acid at 37 degrees C. Ileal uptake from the patients was 0.10 and 0.34 mumol/g dry wt . min in 0.1 mM taurocholic acid, 1.20 and 2.39 mumol/g dry wt . min in 1.0 mM taurocholic acid, and 21.19 and 11.14 mumol/g dry wt . min in 10.0 mM taurocholic acid. At every concentration, significant (p less than 0.05) reductions were present compared with ileum from 7 ileostomy controls, 0.5 to 27 yr old whose uptake was 1.40 +/- 0.28 mumol/g dry wt . min (mean +/- SEM) at 0.1 mM; 6.36 +/- 1.33 mumol/g dry wt . min at 1.0 mM, and 76.20 +/- 19.30 mumol/g dry wt . min at 10.0 mM taurocholic acid. Ultrastructural examination of the ileal mucosa failed to demonstrate a significant structural abnormality. Significant reduction in ileal uptake of taurocholic acid accompanying clinical and biochemical findings of interruption of the enterohepatic circulation in the absence of mucosal disease suggests that these children have a previously undescribed, congenital transport defect that includes absence of active ileal bile acid transport presenting as diarrhea in infancy.

Bile Acids and Salts↗
PubMed1981

Arginine deficiency syndrome. Its occurrence in carbamyl phosphate synthetase deficiency.

A child with carbamyl phosphate synthetase deficiency was studied. During attempts at dietary control, a peculiar rash and cessation of growth were noted concomitant with a very low serum arginine level. A prospective study was designed so that the only variable would be the addition of 400 mg of arginine to his diet. During the two-week period without arginine, the rash and growth failure recurred and paralleled a drop in the serum arginine level from 0.048 to 0.034 nmol/mL. Then with the addition of arginine, his rash dramatically cleared and he resumed normal growth. Later, it became necessary to raise his arginine intake to 800 mg/day to maintain continued growth. These data support the concept that arginine becomes an "essential" amino acid in persons with urea cycle defects, which may partially explain the extremely variable clinical manifestations and courses seen in these patients.

Amino Acids, Essential↗
PubMed1980

Enterohepatic circulation of bile acids in infants and children with ileal resection.

Seven children who had undergone ileal resection of varying lengths as neonates were studied to determine later gastrointestinal function with specific emphasis on the enterohepatic circulation of bile acids. Fecal homogenate and aqueous supernatant bile acid concentrations and serum bile acids were analyzed. Cholic acid kinetics were measured by the isotopic dilution technique, with multiple duodenal bile samples obtained within 48 hr after intravenous 14C--cholic acid. As compared to those of age-matched controls, significantly increased fecal homogenate bile acid concentrations (p less than 0.05) and fecal aqueous supernatant bile acid concentrations (p less than 0.01) were present. Fasting and postcibal serum bile acid concentrations were significantly reduced (p less than 0.001). Increased FTRs for cholic acid (p less than 0.001) were present in children with resection. The FTR correlated significantly with resection length (p = 0.012). Fasting pool sizes of chenodeoxycholic and cholic acid measured after an overnight fast were variable. Three children had significantly reduced cholic acid and chenodeoxycholic acid pools, and one had a reduction in the cholic acid pool only. The cholic acid pool size correlated directly with the postprandial rise in serum CG concentration (p = 0.003). The fecal coefficient of fat excretion and fecal weights were only moderately increased. Although rapid turnover of bile acids was present following neonatal ileal resection, efficient compensatory mechanisms during infancy and childhood allowed adequate intraluminal bile salt concentrations for normal fat solubilization throughout the day and resultant mild steatorrhea and diarrhea in our study patients.

Bile Acids and Salts↗
PubMed1979

Refractory infantile diarrhea due to primary bile acid malabsorption.

A boy is described who had severe, refractory diarrhea beginning soon after birth. Prolonged parenteral alimentation was required to support life. Investigations of bile acid metabolism showed impaired intestinal absorption of bile acids. Contracted bile acid pool sizes resulted, with low intraluminal bile acid concentrations and severe, malabsorption of water and fat. Bile acid malabsorption is a cause of refractory infantile diarrhea.

Bile Acids and Salts↗
PubMed1979

Neuropsychologic consequences of Reye syndrome.

Behavioral measurement of brain function was conducted in 40 children, one or more years after their recovery of Reye syndrome. Test measures included standard indices of intelligence, school achievement, visual-motor coordination and social maturity, plus the Halstead-Reitan Neuropsychological Batteries. There was a strong correlation between the degree of impaired neuropsychologic function and clinical grade at admission, the duration of impaired consciousness, and the number of exchange transfusions required. Patients with milder disease had normal brain function and fewer school problems. Language and perceptual-motor performance significantly improved with increasing years in recovery, suggesting that some of the disturbances of brain functioning are transient. The statistical analysis indicated that there are lasting, often subtle disturbances of higher cognitive function as a result of Reye syndrome. These deficits, not always apparent on clinical examination, are clearly correlated with the extent of neurologic involvement. This quantitative assessment of neuropsychologic function is a basis for determining the "quality of survival" in Reye syndrome, and such measurements should be included in the comparative evaluation of Reye syndrome treatment programs.

Achievement↗
PubMed1979

Small intestinal mucosal fatty acid uptake and esterification in infants and children.

Oleic acid uptake and esterification in intact intestinal mucosa were studied in 14 infants and children with chronic non-specific diarrhea, but histologically normal small intestinal mucosal biopsies, using an in vitro technique. The uptake rate was 5.876 +/- 1.942 nmol fatty acid/mg Nigrogen/minute and the esterification rate was 4.060 +/- 1.010 nmol fatty acid/mg Nitrogen/minute, comparable to previous adult esterification studies. No effect of age on either esterification or uptake was present. Mucosal injury resulted in significant reductions in esterification (p less than 0.001) and uptake (p less than 0.05) compared to controls. Bile acid deficiencies led to reductions in mucosal esterification (p less than 0.05) but not uptake.

Bile Acids and Salts↗