[Uniform intervention criteria for jaundice in hyperbilirubinemia in preterm infants]

OBJECTIVE

To compare the guidelines of the 10 Dutch neonatal intensive care units (NICUs) for the treatment of preterm infants with hyperbilirubinemia, in order to develop uniform threshold levels for the total serum concentration of bilirubin (TSB) above which treatment with phototherapy or exchange transfusion is indicated.

DESIGN

Survey.

METHODS

Guidelines for hyperbilirubinemia in preterm infants (gestational age < 32 weeks) from all 10 Dutch NICUs were obtained and compared with each other and with international guidelines.

RESULTS

All 10 NICUs used intervention criteria based on TSB. 9 NICUs used TSB thresholds based on birth weight (1 used gestational age) with 2, 3 or 5 categories. 6 NICUs used age-specific TSB thresholds and 4 NICUs used a constant TSB threshold. The maximum range in TSB thresholds was 170 micromol/l for phototherapy and 125 micromol/l for exchange transfusion. Acidosis, sepsis, asphyxia, active haemolysis and intraventricular haemorrhage were the risk factors most frequently used. During a consensus meeting with representatives of the 10 NICUs, a guideline was agreed upon that will now be used for all neonates with a gestational age < 35 weeks.

CONCLUSION

There was considerable variation in the TSB thresholds used to date by the 10 NICUs. Now in the Netherlands, in addition to guideline 'Hyperbilirubinemia' for children with a gestational age >or= 35 weeks, 'uniform yellow thresholds' shall be used for jaundiced preterm infants with a gestational age < 35 weeks.

Usefulness of the bilirubin/albumin ratio for predicting bilirubin-induced neurotoxicity in premature infants

Unconjugated hyperbilirubinaemia occurs in almost all premature infants and is potentially neurotoxic. Treatment is based on total serum bilirubin (TSB), but treatment thresholds are not evidence based. Free bilirubin (Bf)-that is, not bound to albumin, seems a better parameter for bilirubin neurotoxicity, but measurements of Bf are not available in clinical practice. The bilirubin/albumin (B/A) ratio is considered a surrogate parameter for Bf and an interesting additional parameter in the management of hyperbilirubinaemia. This paper reviewed the evidence supporting the use of B/A ratios for predicting bilirubin-induced neurological dysfunction (BIND) including neurodevelopmental delay in jaundiced premature infants (gestational age less than 32 weeks). A literature search was performed and six publications reviewed regarding B/A ratios in the management and outcome of jaundiced premature infants. No prospective clinical trials had been undertaken to show whether bilirubin-induced neurotoxicity is reduced or whether unnecessary treatment is avoided by using the B/A ratio in addition to TSB. Recently, a randomised controlled trial evaluating the effect of the additional use of the B/A ratio on neurodevelopmental outcome in jaundiced premature infants has been initiated. Based on the prevailing evidence many authorities suggest that the additional use of the B/A ratio may be valuable when evaluating jaundiced premature infants.

Energy requirements

The determination of the appropriate energy and nutritional requirements of a newborn infant requires a clear goal of the energy and other compounds to be administered, valid methods to measure energy balance and body composition, and knowledge of the neonatal metabolic capacities. Providing an appropriate amount of energy to newborn infants remains a challenge considering the great number of newborn infants who suffer in-hospital growth retardation. The energy requirements of a newborn infant are influenced by several factors - basal metabolism, growth, energy expenditure, and energy losses - which change continuously during development. Calculating the energy requirements of preterm infants is subject to error if general recommendations are applied without recognition of the large variation in factors that influence, for example, energy expenditure. Therefore, energy recommendations should be individualized and preferably based on measurements of energy expenditure. In particular, extremely low birth-weight and very low birth-weight infants are prone to develop negative energy and nutrient balances, due to low energy intake, low energy reserves and high energy demands. Early energy accretion is not only essential for growth but also influences neurodevelopmental outcome and physical health in the long term, thereby underlining the importance of adequate neonatal nutrition.

Mosaic isodicentric chromosome 18q: sixth report and review

We describe a girl with a mosaic isodicentric chromosome 18q with discrete features of trisomy 18. She presented with prenatal growth retardation, prominent occiput, small face, high nasal bridge, large nose, thin lips, a perimembranous ventricular septal defect, and subsequent slow psychomotor development and slow growth. Amosaic isopseudodicentric chromosome 18q was detected in cultured lymphocytes: mos 46,XX,psu idic(18)(q23)[74]/ 46,XX[26]. Monosomy of the distal end of 18q23 could not be confirmed by fluorescent in situ hybridization (FISH) with RP 1l-565D23, one of the most telomere located probes of 18q23. Isopseudodicentric chromosome 18q is very rare. Most cases are mosaics. The phenotype varies. More or less distinct features of trisomy 18 and monosomy 18q can be found depending on the degree of mosaicism and the breakpoint in 18q.

Bile duct proliferation associated with bile salt-induced hypercholeresis in Mdr2 P-glycoprotein-deficient mice

BACKGROUND/AIMS

Bile flow consists of bile salt-dependent bile flow (BSDF), generated by canalicular secretion of bile salts, and bile salt-independent flow (BSIF), probably of combined canalicular and ductular origin. Bile salt transport proteins have been identified in cholangiocytes, suggesting a role in control of BSDF and/or in control of bile salt synthesis through cholehepatic shunting.

METHODS

We studied effects of bile duct proliferation under non-cholestatic conditions in multidrug resistance-2 P-glycoprotein (Abcb4)-deficient multidrug resistance gene-2 (Mdr2(-/-)) mice. BSDF and BSIF were determined in wild-type and Mdr2(-/-) mice during infusion of step-wise increasing dosages of tauroursodeoxycholate (TUDC). Cholate synthesis rate was determined by 2H4-cholate dilution. Results were related to expression of transport proteins in liver and intestine.

RESULTS

During TUDC infusion, BSDF was increased by approximately 50% and BSIF by approximately 100% in Mdr2(-/-) mice compared with controls. Cholate synthesis rate was unaffected in Mdr2(-/-) mice. Hepatic expression of the apical sodium-dependent bile salt transporter (Asbt), its truncated form (tAsbt) and the multidrug resistance-related protein 3 were upregulated in Mdr2(-/-) mice.

CONCLUSIONS

Bile duct proliferation in Mdr2(-/-) mice enhances cholehepatic shunting of bile salts, which is associated with a disproportionally high bile flow but does not affect bile salt synthesis.

Progressive facial hemiatrophy: a complex disorder not only affecting the face. A report in a monozygotic male twin pair

Progressive facial hemiatrophy (PFH) is a ubiquitous disease, characterized by hyperpigmentation of skin followed by unilateral craniofacial atrophy of subcutaneous tissues, including fat, muscle and bone. Hereditary factors have been postulated to be involved in the aetiology of PFH. Yet, the occurrence of PFH in one of two identical male twins reported here makes this possibility unlikely. PFH usually occurs in the first two decades of life, and the clinical presentation resembles linear scleroderma. PFH may be complicate by autoimmune, neurological, ocular and dental disorders. Management of PFH comprises a long term follow-up of somatic disorders, and prevention of psychological problems. Treatment of PFH is symptomatic and consists of plastic surgery after the disease activity has stopped.

CONCLUSION

The occurrence of PFH in one of monozygotic twin pair suggests that genetic factors are not involved in its aetiology. Early diagnosis of PFH and accurate follow-up is essential to disclose the occurrence of complications.

Cyclosporine A-induced reduction of bile salt synthesis associated with increased plasma lipids in children after liver transplantation

Hyperlipidemia is a common side effect of cyclosporine A (CsA) after solid organ transplantation. CsA also markedly reduces the synthesis rate of bile salts in rats and can inhibit biliary bile salt secretion. It is not known, however, whether CsA inhibits the synthesis of bile salts in humans, and whether the hyperlipidemic effects of CsA are related to bile salt metabolism. Our objective was to assess the effects of CsA on the synthesis rate of bile salts and on plasma triglycerides and cholesterol levels in pediatric liver transplant patients. Before and after discontinuation of CsA treatment after liver transplantation, synthesis rate and pool size of the primary bile salts cholate and chenodeoxycholate were determined using a stable isotope dilution technique and related to plasma lipids. In 6 children (age: 3-16 years) CsA treatment was discontinued at 2 years (median 2.3 years) after liver transplantation. Discontinuation of CsA increased synthesis rate of chenodeoxycholate (+38%, P <.001) and cholate (+21%, P <.05) and the pool size of chenodeoxycholate (+54%, P <.001). Discontinuation of CsA decreased plasma levels of cholesterol (-18%, P <.05) and triglycerides (-23%, P <.05). Bile salt synthesis rate appeared to be inversely correlated with plasma cholesterol (Spearman rank correlation coefficient [r(s)] = -0.82, P <.01) and plasma triglyceride levels (r(s) = -0.62, P <.05). In conclusion, CsA inhibits bile salt synthesis and increases plasma concentration of cholesterol and triglycerides in pediatric liver transplant patients. Suppression of bile salt synthesis by long-term CsA treatment may contribute to hyperlipidemia and thus to increased risk for cardiovascular disease.

Enterohepatic circulation of bile salts in farnesoid X receptor-deficient mice: efficient intestinal bile salt absorption in the absence of ileal bile acid-binding protein

The bile salt-activated farnesoid X receptor (FXR; NR1H4) controls expression of several genes considered crucial in maintenance of bile salt homeostasis. We evaluated the physiological consequences of FXR deficiency on bile formation and on the kinetics of the enterohepatic circulation of cholate, the major bile salt species in mice. The pool size, fractional turnover rate, synthesis rate, and intestinal absorption of cholate were determined by stable isotope dilution and were related to expression of relevant transporters in the livers and intestines of FXR-deficient (Fxr-/-) mice. Fxr-/- mice showed only mildly elevated plasma bile salt concentrations associated with a 2.4-fold higher biliary bile salt output, whereas hepatic mRNA levels of the bile salt export pump were decreased. Cholate pool size and total bile salt pool size were increased by 67 and 39%, respectively, in Fxr-/- mice compared with wild-type mice. The cholate synthesis rate was increased by 85% in Fxr-/- mice, coinciding with a 2.5-fold increase in cholesterol 7alpha-hydroxylase (Cyp7a1) and unchanged sterol 12alpha-hydroxylase (Cyp8b1) expression in the liver. Despite a complete absence of ileal bile acid-binding protein mRNA and protein, the fractional turnover rate and cycling time of the cholate pool were not affected. The calculated amount of cholate reabsorbed from the intestine per day was approximately 2-fold higher in Fxr-/- mice than in wild-type mice. Thus, the absence of FXR in mice is associated with defective feedback inhibition of hepatic cholate synthesis, which leads to enlargement of the circulating cholate pool with an unaltered fractional turnover rate. The absence of ileal bile acid-binding protein does not negatively interfere with the enterohepatic circulation of cholate in mice.

Cyclosporin a and enterohepatic circulation of bile salts in rats: decreased cholate synthesis but increased intestinal reabsorption

Cyclosporin A (CsA) has been shown to inhibit synthesis and hepatobiliary transport of bile salts. However, effects of CsA on the enterohepatic circulation of bile salts in vivo are largely unknown. We characterized the effects of CsA on the enterohepatic circulation of cholate, with respect to synthesis rate, pool size, cycling time, intestinal absorption, and the expression of relevant transporters in liver and intestine in rats. CsA (1 mg. 100 g(-1). day(-1) s.c.) or its solvent was administered daily to male rats for 10 days. Cholate synthesis rate and pool size were determined by a 2H4-cholate dilution technique. Bile and feces were collected for determination of cholate and total bile salts, respectively. Cycling time and intestinal absorption of cholate were calculated. The mRNA levels and corresponding transporter protein levels in liver and intestine were assessed by real-time polymerase chain reaction and Western analysis, respectively. CsA treatment decreased cholate synthesis rate by 71%, but did not affect pool size or cycling time. CsA reduced the amount of cholate lost per enterohepatic cycle by approximately 70%. Protein levels of the apical sodium-dependent bile salt transporter (Asbt) were 2-fold increased in distal ileum of CsA-treated rats, due to post-transcriptional events. In conclusion, chronic CsA treatment markedly reduces cholate synthesis rate in rats, but does not affect cholate pool size or cycling time. Our results strongly suggest that CsA enhances efficacy of intestinal cholate reabsorption through increased Asbt protein expression in the distal ileum, which contributes to maintenance of cholate pool size in CsA-treated rats.

Measurement of parameters of cholic acid kinetics in plasma using a microscale stable isotope dilution technique: application to rodents and humans

A stable isotope dilution method is described that allows measurement of cholic acid (CA) kinetics, that is, pool size, fractional turnover rate (FTR), and synthesis rate in mice, rats, and humans. Decay of administered [2,2,4,4-2H4]CA enrichment was measured in time in 50-microl plasma samples by gas-liquid chromatography/electron capture negative chemical ionization-mass spectrometry, applying the pentafluorobenzyl-trimethylsilyl derivative. The kinetic data expressed species-dependent differences. The CA pool sizes were 16.8 +/- 2.1, 10.6 +/- 1.2, and 2.4 +/- 0.7 micromol/100 g body weight for mice, rats, and humans, respectively. The FTR values were 0.44 +/- 0.03, 0.88 +/- 0.10, and 0.46 +/- 0.14 per day for mice, rats, and humans. The corresponding synthesis rates were 7.3 +/- 1.6, 9.3 +/- 0.1, and 1.0 +/- 0.2 micromol/100 g body weight per day. The human data agreed well with literature data obtained by conventional isotope dilution techniques. For rats and mice these are the first reported isotope dilution data. The method was validated by confirmation of isotopic equilibrium between biliary CA and plasma CA in the rat. Its applicability was demonstrated by the observation of increased CA FTR and CA synthesis rate in rats fed cholestyramine, which is known to increase fecal bile acid excretion. The presented stable isotope dilution method enables the determination of CA kinetic parameters in small plasma samples. The method can be applied in unanesthetized rodents with an intact enterohepatic circulation and may also be valuable when studying the development of human neonatal bile acid kinetics.

Vertebral osteomyelitis associated with cat-scratch disease

We describe a patient with vertebral osteomyelitis and paravertebral soft-tissue collections associated with cat-scratch disease (CSD). Diagnosis was established on the basis of histologic examination and serological and polymerase chain reaction (PCR) tests. Treatment consisted of administration of antibiotics, and although skeletal lesions were persistently evident on radiography the patient showed complete clinical recovery. In addition, 15 cases of documented osteomyelitis associated with CSD are reviewed.

[Accidental ingestion of cigarettes by children]

Accidental ingestion of cigarettes (and butts) is mainly seen in young children. Nicotine in tobacco products is easily absorbed by the oral mucosa and intestines; absorption depends on nicotine content and pH of tobacco. Symptoms are caused by the nicotine component and usually develop rapidly (< 4 hours). The most common symptom is vomiting. Although cigarettes are potentially toxic, their ingestion by children is generally benign. Decontamination of the mouth with water may be useful. Induction of emesis is not advised. Gastric lavage is not needed in asymptomatic patients (with an unreliable history) or after vomiting. Children who ingested cigarettes should receive medical observation for four hours after ingestion. Children with significant symptoms should be admitted and eventually treated by supportive care. In symptomatic children or children with a reliable history of ingestion of large quantities who have not vomited gastric lavage with administration of activated charcoal has to be performed. When after vomiting other symptoms persist activated charcoal can be given via a nasogastric tube.

[Urinary antigen test as a screen for the diagnosis of beta-hemolytic streptococcal infections in newborn infants]

OBJECTIVE

To differentiate between neonates with high and low risk of infections caused by group B beta-haemolytic streptococci (GBS), by using the urinary group B streptococcal antigen test.

DESIGN

Retrospective.

SETTING

Medical Centre Leeuwarden and Public Health Laboratory, Friesland, the Netherlands.

METHODS

In a period of two years clinical, haematological and microbiological (including urinary group B streptococcal antigen detection) data were collected in newborns and their mothers who met one or more of the following criteria: a previous affected child, prolonged (> or = 12 hrs) rupture of membranes, fever in labour, unexpected preterm delivery, unexplained perinatal asphyxia. On the basis of surveillance cultures a colonization rate was made. GBS infection was 'suspected' in an unwell infant with a 'high' colonization rate; infection with GBS was 'proved' by a positive blood culture with GBS.

RESULTS

6 of 342 neonates had an infection with GBS. Risk of invasive infection increased with higher colonization rates. Sensitivity of the antigen test to detect colonization was low, sensitivity to detect neonatal infection was high (51 versus 100%). The negative predictive value of urinary antigen testing was 100%. Prolonged rupture of membranes (1.5% risk of infection) and maternal fever (5%) were the most important risk factors.

CONCLUSION

In healthy neonates with risk factors but with a negative antigen detection test the risk of GBS infection is extremely low. In children with a risk factor a positive test result can indicate heavy colonization or infection. These children should be carefully observed and examined.

Splenic epithelial cysts and splenomegaly: diagnosis and management

Splenomegaly is a common problem. In the absence of systemic illness or malignancy splenic cysts must be considered, especially the epithelial variety. For large cysts total splenectomy has long been recommended. Recognition of the risk of an overwhelming postsplenectomy infection (OPSI), especially in children, has led to spleen conserving surgery. We describe the use of an absorbable Vicryl net after partial splenectomy with total cystectomy in the management of splenic epithelial cysts.

[Progressive partial lipodystrophy; an external problem with internal anomalies]

Progressive partial lipodystrophy (PPL) was diagnosed in two girls aged 6 and 8 years. PPL is characterized by loss of subcutaneous fat, starting in the face and progressing to trunk and arms. Diagnosis is based upon the cachectic appearance and the normal growth parameters. It is a rare disease of unknown aetiology, usually beginning in childhood and more frequent in females. An association with diabetes mellitus, hypertriglyceridaemia and glomerulonephritis has been described. Follow-up should be focused on these and on psychological effects. No causal therapy is available. The facial appearance can be restored by injection of liquid silicones. Life expectancy does not appear to be affected.