Hepatic storage of glycogen in Niemann-Pick disease type B.

We report 2 patients with confirmed Niemann-Pick disease, type B, with previous diagnoses of glycogen storage disease based on excessive glycogen on liver biopsy specimens. These cases emphasize the importance of a complete evaluation, including biochemical confirmation, for patients with suspected metabolic storage diseases.

Chewing gum bezoars of the gastrointestinal tract.

Children have chewed gum since the Stone Age. Black lumps of prehistoric tar with human tooth impressions have been found in Northern Europe dating from approximately 7000 BC (Middle Stone Age) to 2000 BC (Bronze Age). The bite impressions suggest that most chewers were between 6 and 15 years of age. The Greeks chewed resin from the mastic tree (mastic gum). North American Indians chewed spruce gum. The first manufacturing patent for chewing gum was issued in 1869 for a natural gum, chicle, derived from the Sopadilla tree, indigenous to Central America. Chewing gum sold today is a mixture of natural and synthetic gums and resins, with added color and flavor sweetened with corn syrup and sugar. Chewing gum is big business. A significant amount of the $21 billion US candy industry sales is from chewing gums, many of which appeal almost exclusively to children. Despite the history and prevalence of gum chewing, the medical literature contains very little information about the adverse effects of chewing gum. In the present report, we briefly review gum-chewing complications and describe three children who developed intestinal tract and esophageal obstruction as a consequence of swallowing gum.

Use of erythropoietin in Jehovah's Witness children following acute gastrointestinal blood loss.

The decision to transfuse children in families practicing the Jehovah's Witness faith with human blood products raises medical, legal, and moral questions. Two cases are presented in which recombinant human erythropoietin was used in pediatric patients as an alternative following acute gastrointestinal hemorrhage. The patients demonstrated increased hematocrit levels obviating the need for blood transfusion. Although erythropoietin is not an alternative to hemotransfusion in the unstable patient, it may be an option in the hemodynamically uncompromised Jehovah's Witness patient following acute blood loss.

The effect of bile salts on carbonic anhydrase.

Bile salts are potent inhibitors of bovine carbonic anhydrase and human carbonic anhydrase I and human carbonic anhydrase II. To further characterize the binding of bile salts to carbonic anhydrase, rate constants for the CO2 hydration reaction in the presence of deoxycholate, cholate, glycocholate and taurocholate were determined using stop-flow experiments. Values for the Michaelis-Menton dissociation constant for bovine carbonic anhydrase, human carbonic anhydrase I and human carbonic anhydrase II were found to be 5.2, 9.2 and 13.2 mmol/L, respectively. The inhibition constant values for the various bile salts tested ranged from 0.1 to 1 mmol/L for bovine carbonic anhydrase, 1.6 to 2.4 mmol/L for human carbonic anhydrase I and 0.09 to 0.7 mmol/L for human carbonic anhydrase II. Our results suggest a mechanism of noncompetitive carbonic anhydrase inhibition for bile salts. Bile-salt binding to carbonic anhydrases as measured by scanning molecular sieve chromatography resulted in an increase in partition radius, molecular volume and surface area. The partition radius increased from 24 A to 28 A in the presence of 2.5 mmol/L sodium deoxycholate at critical micelle concentration. As determined by sedimentation equilibrium measurements, approximately 1 gm of carbonic anhydrase will bind 0.03 gm of deoxycholate, suggesting three to six binding sites for bile salt on the carbonic anhydrase molecule. The conformational changes and inhibition of carbonic anhydrases resulting from bile-salt binding may be important to the regulation of enzymatic activity in tissues along the enterohepatic circulation; by limiting bicarbonate availability this interaction may also contribute to the metabolic derangements seen in patients with cholestatic liver disease.

Chest pain in teenagers. When is it significant?

Chest pain in teenagers often has no obvious organic cause. Onset of symptoms with an emotionally stressful situation may indicate psychogenic chest pain. The differential diagnosis also includes cardiac, musculoskeletal, gastrointestinal, and respiratory disorders. Routine testing generally does not help to establish a diagnosis and may even do harm by reinforcing a patient's unspoken fear of serious illness. Most teenagers with chest pain have no such illness, and symptoms usually resolve without therapy. An important role for primary care physicians is to provide support during evaluation and follow-up.

Quantitative reappraisal of general expressions for multivalent protein binding in subunit-exchange chromatography.

Quantitative expressions have been derived for bivalent equilibria with immobilized ligand systems and for the equilibria for an immobilized protein whose self-association is modified by binding with a soluble ligand, as analyzed by affinity chromatography. These general expressions have been applied in a reexamination of multivalency in the affinity chromatography of antibodies, as reported by Eilat and Chaiken (Biochemistry 18 (1979) 790) and also to studies of neurophysin-peptide hormone interactions using glass matrices reported by Swaisgood and Chaiken (Biochemistry 25 (1986) 4148).

Chest pain and dysphagia in adolescents caused by diffuse esophageal spasm.

Five adolescents, 13-18 years of age, underwent esophageal manometric studies because of chronic symptoms suggestive of esophageal dysfunction. Four of five patients had episodic nonexertional midchest pain; two patients experienced intermittent dysphagia. The manometric findings for these adolescents were consistent with a primary motility disorder known as diffuse esophageal spasm, a condition not previously reported in this age group. This represents approximately 1% of all pediatric patients undergoing esophageal manometry at our institution for the past 5 years. They have been followed for at least 2 years and three have experienced gradual resolution of their symptoms with normalization of manometric findings. Our report emphasizes two main points: (a) Diffuse esophageal spasm may cause chest pain and dysphagia in adolescents; and (b) the clinical history and esophageal manometric findings establish the diagnosis of diffuse esophageal spasm.

Measurement of plasma prednisolone level to evaluate a prednisone treatment failure in an adolescent with Crohn's disease.

A 14-year-old boy experienced multiple hospitalizations because of symptoms due to Crohn's disease involving the stomach, duodenum, and ileum. He maintained that oral corticosteroids were not effective for control of his symptoms. However, i.v. corticosteroids always relieved his symptoms. To resolve the question of noncompliance versus altered corticosteroid absorption or metabolism, our patient underwent an oral prednisone absorption study. Prednisolone, the active metabolite of prednisone, was measured in his plasma using a high-pressure liquid chromatography technique. The results led to the discovery of an elaborate deception by the patient and his subsequent need for psychotherapy. This report documents the importance of measuring plasma prednisolone concentrations to diagnose noncompliance, especially in adolescents who are overly concerned about their body image.

Effect of vitamin E deficiency on neurologic function in patients with cystic fibrosis.

We evaluated neurologic function in 18 patients, ages 5 to 26 years, with cystic fibrosis. Eight were deficient in vitamin E. Sural nerve conduction latency was increased and nerve action potential amplitude decreased in the vitamin E-deficient group in comparison with the vitamin E-sufficient group. Two vitamin E-deficient patients had absent deep tendon reflexes; findings of clinical neurologic examinations were otherwise normal. We recommend early supplementation with vitamin E for patients with cystic fibrosis who have pancreatic insufficiency, to prevent neurologic dysfunction.