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Biomedical subjects

J A Kerner

Publications and source records attributed to J A Kerner.

At least 37 records · Page 2Linked to original sources
PubMed1991

Microvillous inclusion disease. The importance of electron microscopy for diagnosis.

We report two cases of microvillous inclusion disease (MID) occurring in a set of siblings. Although it is a rare disorder, MID appears to be a common cause of familial intractable secretory diarrhea. Diagnosis rests on the ultrastructural finding of intracytoplasmic inclusions that are lined by intact microvilli. These inclusions are present in the absorptive surface epithelial cells of the small and large intestine and are associated with poorly developed surface brush border microvilli. The prognosis of MID is poor and curative therapy is not currently available. Because MID appears to be a hereditary disorder, genetic counseling of affected families is essential.

Biopsy↗
PubMed1991

Anthropometry and bilirubin production.

Anthropometric measurements and total bilirubin formation (TBF) estimates were performed on infants born to normal and diabetic mothers. Although we do not exclude the theoretical possibility of a low-frequency occurrence of increased TBF in macrosomic infants of normal mothers, we can conclude that infants of mothers whose diabetes is well managed may have normal TBF.

Anthropometry↗
PubMed1990

Regulation of intestinal ontogeny by intraluminal nutrients.

Major events in gastrointestinal ontogeny occur in the infant rat in association with weaning, resulting in striking alterations in small intestinal structure and function. Although the dietary changes attendant to weaning are not essential for the initiation of these events, dietary nutrients have been shown to participate in the maturation of some intestinal parameters. In order to define more precisely the role of intraluminal nutrients in the regulation of small intestinal ontogeny, a longitudinal study was conducted using a unique animal model in which intraluminal nutrients were excluded from the intact maturing intestine in vivo throughout the entire weaning period without major compromise in nutritional status. The absence of intraluminal nutrients over the weaning period resulted in diminished lengthening and accretion of mucosal mass, suggesting a slower rate of intestinal growth. Lower mucosal DNA, protein, and mitotic indices in intestines of animals receiving no intraluminal nutrients suggested that the lack of intraluminal nutrients resulted in the blunting of the striking increases in cellular proliferation normally exhibited by the developing intestinal mucosa at this time. Maturation of intestinal lactase-phlorizin hydrolase and maltase-glucoamylase was not affected by the absence of intraluminal nutrients. Although the appearance of sucrase-isomaltase was not altered by the absence of intraluminal nutrients, activity levels rose to only 50% of control levels. These data suggest that during this period of rapid intestinal maturation, intestinal growth is more dependent upon intraluminal nutrients than are the characteristic enzymic alterations normally expressed during this period.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Carbon monoxide production by nonbacterial sources after heme feeding of neonatal rats.

We determined the relative potential for nonbacterial CO production after oral heme feeding of 12-hour-old rats. The intestinal flora was eliminated by treatment with kanamycin, ampicillin, and neomycin. CO excretion (VeCO) was measured after oral administration of heme (0.64 mumol/animal). Antibiotic treatment alone did not significantly affect the VeCO of rats gavaged with saline. Heme administration increased (p less than 0.05) the VeCO during t = 1-11 h with a peak at 3 h. Antibiotic treatment reduced this VeCO (p less than 0.05) during t = 2-8 h, but its level (peak at t = 2-3 h) was still significantly (p less than 0.05) above its nonheme control. The results confirm that bacterial degradation of heme is an important source of CO in suckling rats not pretreated with broad-spectrum antibiotics. However, oral heme feeding of gut-sterilized animals yielded transiently significantly increased VeCO. HO-mediated degradation of enteral heme is a likely nonbacterial source of CO and possibly bilirubin in the neonate.

Administration, Oral↗
PubMed1985

The nature of maturational decline of intestinal lactase activity.

We have examined the nature of the decline of lactase (EC 3.2.1.23) activity in the maturing rat intestine. It was established in an initial study that the activity decline reflected a proportional reduction in the concentration of the enzyme protein. Accumulation patterns of label into lactase, total intestinal proteins and sucrase (EC 3.2.1.48)-isomaltase (EC 3.2.1.10) were compared, 4 h following administration of a tracer dose of [3H]leucine to weanling rats exhibiting a wide range of lactase decline. Accumulation of increasing amounts of label in total intestinal proteins and sucrase-isomaltase pools was found to accompany the lactase decline, in contrast to accumulation of a constant amount of label in the declining lactase pools. The pattern of increased label accumulation in total intestinal proteins was shown in a corollary study to reflect a corresponding acceleration of total protein synthesis. On this basis, the finding of a constant amount of label in the declining lactase pools suggested a constant synthesis of lactase. We proposed earlier that associated reductions in enterocyte life-span (leading to correspondingly less lactase accumulation) rather than suppressed synthesis may provide the primary causal basis of lactase decline in the postweaned mammal.

Aging↗
PubMed1985

Intestinal flora in the second week of life in hospitalized preterm infants fed stored frozen breast milk or a proprietary formula.

Twenty infants fed stored frozen breast milk or a proprietary formula only had both aerobic and anaerobic cultures performed at a chronologic age of 8 to 14 days. Nine out of 10 stools from the infants fed stored frozen breast milk contained Enterobacteriaceae and one stool was sterile. One contained a Pseudomonas species; one contained anaerobic gram-positive rods; one contained anaerobic gram-negative rods; and four contained anaerobic gram-positive cocci. No anaerobes were found in six stools. Six stools had aerobic gram-positive cocci, none of which was hemolytic. Nine out of 10 stools from infants fed a proprietary formula had Enterobacteriaceae. Six stools had anaerobic gram-positive rods, three had anaerobic gram-negative rods, and four had gram-positive cocci. Four stools had no anaerobic bacteria. All 10 stools had nonhemolytic aerobic gram-positive cocci. Enterobacteriaceae were predominant in the stools of the infants fed either stored frozen breast milk or a proprietary formula, and the colony counts of aerobic bacteria were similar in both groups. This pattern of intestinal flora in hospitalized preterm infants in the second week of life is very different from that of normal term infants and may contribute to their increased incidence of systemic and localized infections. The use of stored frozen breast milk for the purpose of suppressing coliform and other potentially pathogenic organisms may not be effective in hospitalized preterm infants who have been treated previously with broad-spectrum, parenteral antibiotics.

Bacteria↗
PubMed1984

Bilirubin binding in the plasma of newborns: critical evaluation of a fluorescence quenching method and comparison to the peroxidase method.

Bilirubin binding affinities and capacities and apparent unbound ("free") bilirubin levels were determined in serum samples from 47 high-risk newborns, in 22 samples of cord serum, and in serum samples from 15 Greek children with marked hyperbilirubinemia, by both fluorescence quenching and peroxidase methods. The free fatty acid:albumin molar ratio was also determined for serum samples from high-risk newborns. In vitro and in vivo measurements suggest that free fatty acids are rarely present at levels that produce significant displacement of bilirubin, which is in agreement with previous studies. The two bilirubin binding assays showed only fair correlation with sizable discrepancies for many specimens. Technical difficulties inherent in the fluorescence quenching method and possible sources of error are discussed. Our observations suggest that routine application of these two assays as the primary criterion for therapeutic intervention (e.g., exchange transfusion) is premature.

Bilirubin↗
PubMed1983

Breath hydrogen analysis: a review of the methodologies and clinical applications.

Hydrogen gas (H2) is a product of the fermentation of dietary carbohydrate (CHO) by bacteria in the lumen of the gastrointestinal tract in man. Thus, H2 is actually an exogenously produced gas, which either is passed as flatus, or diffuses into the body and is exhaled. In the adult, a fairly constant fraction is expired, providing a reliable indicator of total colonic H2 production. Breath H2 analysis currently represents a useful clinical means of testing adults and older children for the malabsorption of CHO. Noninvasive and easy procedures for the collection of expired air have encouraged their increasingly widespread use in pediatrics. Evidence to date suggests that breath H2 analysis may provide the best available method for estimating semiquantitatively the degree of CHO malabsorption. The association of the results of breath H2 analysis with other clinical measures of CHO digestion and absorption is expected, but discrepancies can also be anticipated based on the nature of this particular trace gas method. The interpretation of the results of breath H2 analysis in neonates and young infants remains especially problematic because of confounding variables which are difficult to control and are measured infrequently.

Adult↗
PubMed1982

Evidence for the possible relationship of neonatal skinfold thickness to maternal glucose metabolism during the third trimester.

Forty-eight infants, including 14 premature infants who were appropriate size for gestational age (AGA), 10 full-term AGA infants, 18 full-term infants who were large for gestational age (LGA), and six premature LGA infants of diabetic mothers (IDMs), had measurements of skinfold thickness (SFT) in the first 72 h of life. For the 24 LGA infants, there was a significant positive correlation between maternal glycohemoglobin (Hb AIc) in the post-partum period and SFT (r = 0.42, p less than 0.05). Our observations in this study support those of others, demonstrating that SFT increases with increasing gestational age. In addition, they support the hypothesis that, in diabetic pregnancies, or pregnancies associated with an elevated Hb AIc, a reflection of the time-integrated blood glucose level over the weeks preceding parturition, fetal hyperglycemia and hyperinsulinemia stimulate increased triglyceride synthesis in adipose cells and lead to an increase in fetal subcutaneous fat.

Birth Weight↗
PubMed1982

A sensitive analytical apparatus for measuring hydrogen production rates. II. Application to studies in human infants.

We estimated hydrogen (H2) production by determining simultaneously the end-tidal concentration (ETH2) and the direct pulmonary excretion rate (VeH2) in normal-sized, healthy, term and preterm neonates between 2 days and 7 weeks of life who were receiving all their calories enterally as breast milk or a proprietary formula. We found that there was no peak or pattern in H2 production during the first 3 postprandial hours (mean VeH2 = 1.00 +/- 0.97 SD ml/kg/h; mean ETH2 = 40.3 +/- 33.1 SD ppm). Frequently, there was marked short-term variability of the ETH2 in a given infant (coefficient of variation = 13.4% +/- 18.7%). H2 production was elevated in normal neonates without signs of malabsorption. We found that VeH2 correlated with ETH2 using both nasopharyngeal catheter (r = 0.63; p less than 0.001) and nasal prong (r = 0.71; p less than 0.001) collection techniques. We conclude that breath hydrogen determinations in neonates are not readily comparable to similar studies in older patients. Longitudinal studies of individual infants may reveal changes in breath H2 excretion of sufficient magnitude to be distinguishable from moment-to-moment variations, and correlatable with certain intercurrent clinical problems affecting intestinal H2 production or pulmonary H2 excretion. However, interpretation of breath H2 determinations in human infants will be difficult.

Breath Tests↗