Harry L. Greene

A controlled comparison of continuous versus intermittent feeding in the treatment of infants with intestinal disease

We compared two feeding regimens, continuous intragastric feedings and intermittent oral feeding, in nine infants with protracted diarrhea and malnutrition and two infants with surgically created short bowel. Continuous nasogastric feeding caused significant increases in enteral balance of the major nutrients, whereas intermittent feedings resulted in negative or only slightly positive enteral balance. The improvements in enteral balance from intermittent to continuous feeding in infants with diarrhea were as follows: Fat from 13 +/- 0.8 to 22 +/- 2.0 gm/24 hours; nitrogen from 0.63 +/- 0.2 to 1.7 +/- 0.2 gm/24 hours; calcium from -63 +/- 20 to 145 +/- 4 mg/24 hours; zinc from -0.57 +/- 0.2 to 1.3 +/- 0.2 mg/24 hours; and copper from -0.09 +/- 0.03 to 0.21 +/- 0.02 mg/24 hours. There was also a significant increase in body weight during the continuous feeding (168 +/- 16 gm/72 hours) as compared to the intermittent feeding (-171 +/- 26 gm/72 hours). Similar improvements in enteral balance were seen in the two infants with short bowel. These findings document that improved enteral balance can be achieved with continuous feeding in infants with bowel disease.

Intravenous lipid emulsions and human neutrophil function

THE BENEFHS to be gained by adequate nutri t ion in host defense are well recognized? ~ Although the use of fat emulsions has been of value to increase nutrient intake, these emulsions have been noted to markedly impair neutrophil function as judged by in vitro chemotaxis and bactericidal assays? Consequently, the use of alternate means of supplementing nutri t ion has been suggested. 7 To better define the legitimate place for lipid emulsions in parenteral nutr i t ion therapy, we assessed the effect of two commonly used preparations on several neutrophil functions and addressed the mechanism by which the emulsions interfere with cell function.

Chronic relapsing pancreatitis in childhood

We report 10 children with chronic relapsing pancreatitis. These patients can be divided into three groups, based on their clinical history, manifestations, and radiographic findings. Group 1 includes four patients with hereditary pancreatitis; these patients have had recurrent abdominal pain since early childhood, and have a positive family history for pancreatitis. Group 2 includes two patients with clinical and radiographic findings similar to those in patients with hereditary pancreatitis but without a family history of pancreatitis. Group 3 includes four patients with fibrosing pancreatitis who had symptoms and signs of obstructive jaundice. Our report emphasizes three points: (1) that chronic pancreatitis does occur in young children and is most commonly caused by hereditary pancreatitis or fibrosing pancreatitis; (2) that endoscopic retrograde cholangiopancreatiography is a safe and valuable tool for the study of pancreatic and common bile ducts; and (3) that surgical intervention is indicated to drain the pancreatic duct in patients with hereditary pancreatitis, and sphincterotomy is an effective therapy for patients with fibrosing pancreatitis.

Isolated Congenital Enterokinase Deficiency Recent Findings and Review of the Literature

We report a 13-mo-old patient with isolated congenital enterokinase deficiency and review the clinical features, diagnostic approach, and management of all 8 reported patients. Our patient presented with failure to thrive, diarrhea, and hypoproteinemia since birth. A normal sweat chloride with small intestinal histology, and nondetectable trypsin activity in the duodenal fluid should alert the physician to the possibility of isolated enterokinase deficiency. All reported patients, including our own, responded favorably to pancreatic enzyme replacement. In vitro studies of the small intestinal mucosal biopsy specimen suggest that enterokinase deficiency at least in part is due to altered enzymes with low enterokinase activity.

Analysis of aldehydic lipid peroxidation products by TLC/densitometry

We have explored the use of thin-layer chromatography (TLC)/densitometry in both the reflectance and fluorescence mode for quantitation of specific products of lipid peroxidation. Aldehydic peroxidation products were generated by exposure of arachidonic acid to iron and ascorbic acid for 24 hr. Several methods for the quantitative analysis of peroxidation products by TLC/densitometry were compared using two different aldehydespecific derivatizing reagents, namely dinitrophenylhydrazine (DNPH) and cyclohexanedione (CHD). DNPH hydrazones of the arachidonic acid-peroxidation products, upon TLC separation on silica gel, revealed prominent alkanal and hydroxyalkenal bands. Reverse phase high performance liquid chromatography confirmed that the primary alkanal component was hexanal, while the primary hydroxyalkenal was 4-hydroxynonenal. Semiquantitative methods for the direct analysis of these products by TLC/densitometry were worked out based on the use of external hydrazone standards. TLC/densitometry (fluorescence mode) was used to measure CHD adducts of aldehydes by forming the derivatives in the presence of decanal (used as an internal standard) and separating the derivatives by reverse phase TLC. Hexanal-CHD was detectable upon application of 0.5 nanomoles while 4-hydroxynomenal showed a lower response and was detectable with 10 nanomoles. Using appropriate response factors, hexanal and 4-hydroxynonenal were measured in the aldehyde sample from arachidonic acid and results were similar to those obtained by the DNPH method.Similar approaches were used to analyze the peroxidation products of docosahexaenoic acid (24-hr exposure) The DHA peroxidation products contained extremely low levels of alkanals, while polar aldehydes and hydroxyalkenals were prominent. Formation of alkanals, osazones, hydroxyalkenals and phospholipid aldehydes from iron-exposed microsomes was also demonstrated. Uses and limitations of these methods of aldehyde measurement are discussed.

Valproate hepatotoxicity: Two new cases, a summary of others, and recommendations

There are two types of hepatotoxicity associated with valproate therapy--dose-related and idiosyncratic. The former may cause alterations in liver function as determined by laboratory examinations and is not associated with death. Idiosyncratic hepatotoxicity is rare, usually irreversible, and not predictable on the basis of laboratory monitoring. Two new cases are reported along with a selected, brief literature review and the authors suggestions for the use of valproate.

Biphasic changes in phospholipid hydroperoxide levels during renal ischemia/reperfusion☆

The involvement of lipid peroxidation in renal ischemia/reperfusion was explored by measuring changes in the cortical content of specific primary lipid hydroperoxides (using chemluminescent detection with HPLC) following ischemia and reperfusion and by correlating the changes in hydroperoxide content with measurements of renal blood flow. Phosphatidylcholine and phosphatidylethanolamine hydroperoxide concentrations were significantly lowered during 30 or 60 min of ischemia (to levels less than 50% of control at 60 min). Following 30 min of renal ischemia, reperfusion resulted in a rebound of phospholipid hydroperoxide tissue content to levels higher than controls. Increased phospholipid hydroperoxide formation was not, however, observed in response to reperfusion following long-term (60 min) ischemia. In separate animals it was demonstrated that following 30 min ischemia and reperfusion, renal blood flow recovers to about 65% of control in 1 h. In contrast, following 60 min ischemia and reperfusion, the renal blood flow remains more highly impaired (less than 25% recovery for periods up to 24 h). These results imply that phospholipid hydroperoxides are produced and accumulate in the kidneys under normal aerobic conditions and that lipid peroxidative activity increases during renal ischemia/reperfusion to an extent dependent on the degree of local blood perfusion.

Tube Feeding of Infants and Children

Advances in tube feeding methods, equipment, and formulas have helped to make this form of nutritional support appropriate for and well tolerated by children with a wide variety of clinical problems. This article describes advances in the field of enteral feeding and discusses the management of common problems associated with this technique.

Identification of hydroxyalkenals formed from omega-3 fatty acids

The highly toxic lipid peroxidation product, 4-hydroxynonenal, is formed from the decomposition of hydroperoxides of omega-6 fatty acids. In this study the analogous hydroxyalkenals formed from the decomposition of hydroperoxides of omega-3 fatty acids (eicosapentaenoic acid and docosahexaenoic acid) were isolated and identified using TLC densitometry, HPLC and GC/Mass Spectrometry. The major hydroxyalkenal formed from both fatty acids was a diene analog of 4-hydroxynonenal, 4-hydroxynona(2,6)dienal, while 4-hydroxyhexanal was a minor product. Measurement of specific omega-3 lipid peroxidation products may be important in studies using dietary fish oil.

Intestinal transport of zinc in the diabetic rat

Zinc has been implicated to play a role in the pathogenesis and management of diabetes. Since the intestinal transport of several minerals as calcium, magnesium and strontium was found to be altered in the diabetic rats, we postulated that intestinal zinc transport may be also altered in the diabetic rat. Therefore, using invivo single pass perfusion technique we determined lumen to mucosa flux, net absorption and the mucosa to lumen flux of zinc in the small and large intestinal segments of diabetic rats, diabetic rats treated with insulin and in control rats. Tissue distribution of transported 65Zn into various organs and tissue concentrations of native zinc in the groups of rats studied were determined. Our results indicate that lumen to mucosa flux (μmole/h/g wet weight) was decreased in all intestinal segments of the diabetic rats compared to controls. However, the total capacity (mμmole/h/cm length) was similar. The specific activity and total capacity of net absorption of zinc was similar in all intestinal segments of the rats studied. The reverse mucosa to lumen flux was significantly decreased in all segments of diabetic rats compared to corresponding values in control rats. Tissue distribution of 65Zn following the perfusion study showed increased retention of 65Zn in the liver, kidney and femurs of the diabetic rats compared to controls. Serum and tissue concentration of native zinc in various organs were similar in all groups of rats studied. The mechanism(s) responsible for these findings are discussed.