[Teaching medical students informed consent]. / Chirurgisches Aufklärungsgespräch in der studentischen Lehre.

BACKGROUND AND OBJECTIVES: Teaching competencies in communication are important for medical education, but implementation in the surgical curriculum is still deficient. Communication during informed consent is one main issue. The aim of the study was to implement a reproducible teaching module for informed consent, which closely represents reality. MATERIAL AND METHODS: In the existing practical surgical course we implemented a module for practising communication during surgical informed consent with the help of standardized patients and feedback rounds. The outcome was assessed during a clinical examination and the students evaluated the module. RESULTS: The module was evaluated by the students positively and deemed helpful for their later work as a doctor. The outcome at clinical examination was 63% (mean) for content and structure of the informed consent and 92% for competency in communication. CONCLUSION: For improving the quality of informed consent, teaching competencies in communication during informed consent should be implemented in the curriculum of medical studies, but legal and content-based aspects should not be ignored.

Pulmonary flow reserve in children with idiopathic pulmonary arterial hypertension: implications for diagnosis and therapy.

AIMS: Endothelial dysfunction is likely to contribute to the pathogenesis of idiopathic Pulmonary Arterial Hypertension (iPAH). We hypothesize that there are different patterns of endothelial cell function, which we studied in 17 children with iPAH. METHODS AND RESULTS: Pulmonary flow reserve was determined by acetylcholine infusion into segmental pulmonary arteries utilizing quantitative angiography and intra-arterial Doppler flow wire. Depending on the reactivity of the pulmonary to systemic arterial pressure ratio to short-term oxygen and intravenous epoprostenol or aerosolized iloprost responders and nonresponders were classified. In 7 responders to oxygen-prostanoid administration the pressure ratio decreased from 0.9 +/- 0.2 to 0.31 +/- 0.11 (p = 0.01), the mean pulmonary flow reserve showed an excessive increase to 3.6 +/- 2.0 (p = 0.01) after infusion of acetylcholine. In 10 non-responders the pressure ratios remained unchanged during oxygen-prostanoid testing. 4 of 5 patients without any effect to acetylcholine died despite long-term epoprostenol treatment. The other 5 nonresponders to oxygen-prostanoid showed an impaired but significant increase of the pulmonary flow reserve of 1.6 +/- 1.1 (p = 0.01). 2 of these patients did not only improve clinically, but regained vascular reactivity by additional therapy with sildenafil. CONCLUSION: Endothelial reactivity in iPAH is either extensive, impaired or absent. Acetylcholine infusion casts a light on the pathogenesis and has implications for therapy.

PTPN11 mutations play a minor role in isolated congenital heart disease.

PTPN11 missense mutations cause approximately 50% of Noonan syndrome, an autosomal dominant disorder presenting with various congenital heart defects, most commonly valvar pulmonary stenosis, and hypertrophic cardiomyopathy. Atrioventricular septal defects and coarctation of the aorta occur in 15% and 9%, respectively. The aim of this study was to determine if PTPN11 mutations exist in non-syndromic patients with these two relevant forms of congenital heart disease. The 15 coding PTPN11 exons and their intron boundaries from subjects with atrioventricular septal defects (n = 24) and coarctation of the aorta (n = 157) were analyzed using denaturing high performance liquid chromatography and sequenced if abnormal. One subject with an atrioventricular septal defect but no other known medical problems had a c.127C > T transition in exon 2, predicting a p.L43F substitution. This mutation affected the phosphotyrosine-binding region in the N-terminal src homology 2 domain and was close to a Noonan syndrome mutation (p.T42A). An otherwise healthy patient with aortic coarctation had a silent c.540C > T change in exon 5 corresponding to p.D180D. Our study showed that PTPN11 mutations are rarely found in two isolated forms of congenital heart disease that commonly occur in Noonan syndrome. The p.L43F mutation belongs to a rare class of PTPN11 mutations altering the phosphotyrosine-binding region. These mutations are not predicted to alter the autoinhibition of the PTPN11 protein product, SHP-2, which is the mechanism for the vast majority of mutations causing Noonan syndrome. Future studies will be directed towards understanding these rare phosphotyrosine binding region mutants.

Misleading diagnosis of partial N-acetylglutamate synthase deficiency based on enzyme measurement corrected by mutation analysis.

UNLABELLED: N-acetylglutamate synthase (NAGS) deficiency is a rare urea cycle disorder. Most of the patients present in the early neonatal period with severe hyperammonaemia and marked neurological impairment. We report on a Turkish family with an index patient, who died due to hyperammonemia, and another three siblings, who received a prophylactic treatment consisting of arginine hydrochloride, sodium benzoate and phenylbutyrate directly after birth. Enzyme measurement in a liver biopsy suggested a diagnosis of partial NAGS deficiency in all three siblings. Thereafter, N-carbamylglutamate was added to the treatment. None of the patients developed hyperammonaemia. After the human NAGS gene was identified, mutation analysis revealed that the consanguineous parents and two siblings were heterozygous for a private mutation (W484R), whereas the wild-type gene was found in the eldest sibling. Therapy was stopped without any deterioration of urea cycle function. CONCLUSION: Diagnosis of partial NAGS deficiency based on enzyme measurement may be misleading and should be completed by mutation analysis.

Primary carnitine deficiency: adult onset lipid storage myopathy with a mild clinical course.

We studied two adult patients with myalgia and muscular fatigability during prolonged physical exercise. Serum creatine kinase was increased and muscle biopsy revealed a lipid storage myopathy affecting predominantly the type I fibres. Skeletal muscle carnitine content was reduced to 15% and 21% of the normal mean values, while serum carnitine levels were either normal or decreased. Four months of oral therapy with L-carnitine (3 g per day) resolved the clinical symptoms completely in both patients, and a subsequent muscle biopsy confirmed a marked reduction of lipid storage, along with increased muscle carnitine levels. The analysis of renal carnitine excretion and the exclusion of possible secondary carnitine deficiencies in both patients are compatible with mild defects of the carnitine transporter in one patient and of carnitine biosynthesis in the other. Since myalgia and muscular fatigue are frequent but unspecified complaints of otherwise clinically unremarkable adult patients, it is important to identify myopathies associated with primary carnitine deficiency because they may be amenable to treatment.

Plasma arginine and urinary nitrate and nitrite excretion in bronchopulmonary dysplasia.

The aim of this prospective study was to determine whether preterm infants with bronchopulmonary dysplasia (BPD) and signs of increased pulmonary artery pressure have a deficiency of plasma arginine (ARG) and systemic nitric oxide (NO) synthesis. Plasma amino acid concentrations, Doppler pulmonary systolic time intervals (ratio of acceleration time and ejection time corrected for heart rate: AT/ET(C)) and urinary nitrate and nitrite concentrations were determined at the 28th day postnatal age and at 36 weeks postmenstrual age in 73 preterm infants less than 30 weeks gestational age. The AT/ET(C) ratios were significantly lower in infants with BPD (n = 32) compared to controls. However, total amino acid concentrations, ARG intake as well as plasma ARG concentrations were not different between groups (median (interquartile-range) micromol/l): control: 58 (42.5-75.5) and 54.5 (42-71) at day 28 and 36 weeks; BPD: 54.5 (31.5-70.5) and 43 (35-62), respectively. Urinary nitrate and nitrite concentrations, were not different between groups at day 28, but significantly higher in infants with BPD at 36 weeks (p = 0.014). In conclusion, plasma ARG concentrations and systemic NO synthesis were not deficient in preterm infants with BPD and signs of elevated pulmonary artery pressure.

Stenting of the ductus arteriosus and banding of the pulmonary arteries: basis for various surgical strategies in newborns with multiple left heart obstructive lesions.

OBJECTIVE: To present an institutional experience with stent placement in the arterial duct combined with bilateral banding of the pulmonary artery branches as a basis for various surgical strategies in newborns with hypoplastic left heart obstructive lesions. DESIGN: Observational study. SETTING: Paediatric heart centre in a university hospital. PATIENTS: 20 newborns with various forms of left heart obstructive lesions and duct dependent systemic blood flow. INTERVENTIONS: Patients underwent percutaneous ductal stenting and surgical bilateral pulmonary artery banding. Atrial septotomy by balloon dilatation was performed as required, in one premature baby by the transhepatic approach. MAIN OUTCOME MEASURES: Survival; numbers of and reasons for palliative and corrective cardiac surgery. RESULTS: One patient died immediately after percutaneous ductal stenting. One patient died in connection with the surgical approach of bilateral pulmonary banding. Stent and ductal patency were achieved for up to 331 days. Two patients underwent heart transplantation and two patients died on the waiting list. Ten patients had a palliative one stage procedure with reconstruction of the aortic arch and bidirectional cavopulmonary connection at the age of 3.5-6 months. There was one death. One patient is still awaiting this approach. Two patients received biventricular repair. In one, biventricular repair will soon be provided. CONCLUSIONS: Stenting the arterial duct combined with bilateral pulmonary artery banding in newborns with hypoplastic left heart or multiple left heart obstructive lesions allows a broad variation of surgical strategies depending on morphological findings, postnatal clinical conditions, and potential ventricular growth.

Influence of gestational age and intrauterine growth on leptin concentrations in venous cord blood of human newborns.

BACKGROUND: The ob gene product leptin is involved in the regulation of body weight and energy expenditure, suggesting a potential role of leptin in embryonal and fetal development and progression of pregnancy. In term infants, leptin concentrations showed a positive correlation with birth weight. We aimed at comparing leptin cord blood levels in AGA (appropriate for gestational age) to SGA (small for gestational age) preterm and term newborns. PATIENTS AND METHODS: Ninety-seven human newborns, 47 females and 50 males, 33 born at term and 64 born before 36 weeks of gestation, were studied prospectively. Leptin concentrations in venous cord blood were determined using a specific RIA (radioimmunoassay). RESULTS: In term newborns, mean gestational age (GA) was 39 weeks (wk) (+/- 0.7 wk) and mean birth weight (BW) was 3316 g (+/- 473 g); in preterm newborns (n = 64), mean GA was 30 wk (+/- 5.0 wk) and mean BW was 1398 g (+/- 505 g). Mean standard deviation score of birth weight (BW SDS) was calculated as - 0.47. Mean leptin concentrations in term newborns differed significantly from those in preterm newborns (9.21 +/- 2.63 ng/ml vs. 1.58 +/- 0.88 ng/ml; p < 0.0001). In preterm and term infants, leptin concentrations showed a linear correlation with BW (r = 0.46; p < 0.0001) and GA (r = 0.48; p < 0.0001), respectively. Leptin levels were best predicted by an exponential regression model with GA (Leptin = exp(- 4.41 + 0.14 x GA); r = 0.61; p < 0.0001). Using multivariate regression analysis (r = 0.57; p < 0.0001), we found significant influences of GA (p < 0.00001) and BW SDS (p < 0.05) on leptin levels. No difference was observed between leptin values in AGA versus SGA preterm infants. CONCLUSION: These data suggest fetal leptin levels to be primarily determined by GA and additionally modulated by growth restriction in term newborns. We found a dramatic increase at weeks 33 to 35 of gestation and no modulation by BW SDS in very preterm infants.

[Cardiac troponin I after heart surgery corrective operation in infancy and childhood]. / Kardiales Troponin I nach kardiochirurgischer Korrekturoperation im Säuglings- und Kindesalter.

BACKGROUND: Perioperative myocardial damage is an important determinant for postoperative cardiac function and recovery. Cardiac troponin I (cTNI) is a specific marker for myocardial damage. The aim of our study was to evaluate pre- and postoperative cTNI levels, the pattern of elevation in the first four postoperative days and the prognostic value after pediatric cardiac operation. METHODS: Cardiac troponin I levels were measured in 115 children mean age 36 +/- 45 months (range 4 days to 189 months) undergoing elective operation of a congenital heart defect. Routine measurements were made preoperatively, immediately after cardiopulmonary bypass and serially 8, 18, 42, 90, 138 hours thereafter. Data from 13 patients undergoing surgery without cardiopulmonary bypass served as controls. Postoperative cTNI levels were correlated with intra- and postoperative parameters (such as duration of aortic crossclamping, cardiopulmonary bypass time and need for postoperative inotropic support). RESULTS: All preoperative cTNI levels were in the normal range. Postoperatively, the highest median cTNI levels were found in patients after repair of tetralogy of Fallot (TOF), atrioventricular septal defect (AVSD) and implantation of a homo- or xenograft. Postoperative cTNI levels correlated significantly with duration of cardiopulmonary bypass and aortic crossclamping, operative approach (ventriculotomy versus atriotomy) and inotropic support (p < 0.0001). Peak cTNI levels were found immediately after surgery in 77.4% of our patients, 8 hours postoperative in 13.9% and at 18 hours after the surgery in 5.2% of the patients. In three children cTNI continued to increase; a secondary increase was found in one patient. Two of these children died, two had a prolonged postoperative recovery. CONCLUSION: The postoperative level of cardiac troponin I could be used as a marker of perioperative myocardial injury caused by ischemia and operative trauma. Peak levels usually could be obtained immediately after surgery, but a further increase of cTNI during the following 18 hours may occur and is not necessarily related to impaired recovery. However still increasing cTNI levels after 18 hours postoperatively and a secondary increase as well may be used as indicators of poor outcome.

[Cutaneous lesions and blood count changes in a 9-month old girl with glutaric aciduria type I]. / Effloreszenzen und Blutbildveränderungen bei einem 9 Monate alten Säugling mit Glutarazidurie Typ I.

Non-specific cutaneous lesions are common in patients suffering from acute myeloid leukemia (AML). Leukemic skin infiltrates are present in about 30% of cases of monoblastic or myelomonocytic leukemia. The appearance of specific skin lesions can precede bone marrow involvement. We report the case of a 9-month-old girl with acute myelogenous leukemia (FAB M5) and glutaric aciduria type I which initially presented with cutaneous lesions, anemia and leukopenia.

Carnitine transporter OCTN2 mutations in systemic primary carnitine deficiency: a novel Arg169Gln mutation and a recurrent Arg282ter mutation associated with an unconventional splicing abnormality.

Systemic primary carnitine deficiency (CDSP, MIM 212140) is a disorder of fatty acid oxidation manifesting in acute metabolic decompensation or in progressive cardiomyopathy and muscle weakness. Mutations in the plasmalemmal organic cation/carnitine transporter OCTN2 were recently identified in CDSP patients of diverse ethnic backgrounds. We have performed OCTN2 mutation analysis in two unrelated German patients with primary carnitine deficiency and identified three molecular abnormalities. On one of the four chromosomes analyzed, we detected an Arg169Gln missense mutation that affects an arginine residue absolutely conserved in the entire transporter superfamily to which OCTN2 belongs. On the three other chromosomes, we found an Arg282ter nonsense mutation in exon 5. This mutation is embedded into different haplotypes of closely spaced intragenic dimorphisms in our two patients and was recently described in a patient of Asiatic Indian background, so it appears to be a recurrent or ancient founder mutation that may account for more CDSP cases. Finally, we found that the Arg282ter nonsense mutation is associated with a splicing abnormality at the intron 6/exon 7 junction. However, no mutations are present in exon 6, intron 6, or exon 7, suggesting that defective splicing of exon 7 on the Arg282ter allele is due to an unconventional, long-distance mechanism.

Transcription of hepatitis B virus in peripheral blood mononuclear cells from persistently infected patients.

Hepatitis B virus (HBV) has been reported to exist in peripheral blood mononuclear cells (PBMC), but it is not clear whether it replicates there. A precondition for replication should be the formation of covalently closed viral DNA and transcription of all essential viral mRNAs. The mRNAs of HBV form a nested box with common 3' ends. In order to detect even low levels of potential replication, we developed a quantitative reverse transcription-PCR method for detection of a smaller HBV mRNA species in the presence of the larger ones. All three highly viremic patients tested so far had mRNAs for the large and the small surface proteins and the X protein of the virus within PBMC but not in the virus from their sera. Furthermore, we detected by PCR covalently closed viral DNA in their PBMC. These data suggest that HBV may be not only taken up but also replicated by mononuclear blood cells and that these cells may be an extrahepatic site of viral persistence. X mRNA was detected in the largest amount. Possibly, X protein interferes with functions of the mononuclear cells during the immune response against the virus.

Developmental patterns of serum 3 alpha-androstanediol glucuronide.

3 alpha-androstanediol glucuronide (3 alpha diolG) is a marker of peripheral tissue androgen metabolism. There are no previous data regarding complete paediatric reference ranges for 3 alpha diolG. In order to obtain reference values for 3 alpha diolG we have measured serum levels of 3 alpha diolG in 283 healthy children and adolescents, 146 boys and 137 girls, age 1 month to 20 years and 28 adults. A non-extraction, solid phase radioimmunoassay employing a polyclonal antiserum that is specific for 3 alpha diolG was used to measure serum 3 alpha diolG levels (intra assay variation 5.1-10.1%, inter assay variation 2.7-9.0%). There was a strong sex and age dependence (r = 0.8; p < 0.0001) of 3 alpha diolG levels throughout childhood and adolescence with males showing significantly higher levels of the androgen than females (p < 0.05). 3 alpha diolG serum levels (nmol/l +/- SD) correlated significantly with pubertal stage (p < 0.01). Interestingly, in 35 children with CAH serum 3 alpha diolG levels correlated well with clinical and metabolic status, i.e. 17OHP serum levels. In summary, we have established percentile curves for 3 alpha diolG levels in healthy children and adolescents. We hypothesize that on the basis of our reference values the single measurement of serum 3 alpha diolG could serve as a means to determine androgen status in children with disorders of puberty and sexual development.

Developmental patterns of serum 3 alpha-androstanediol glucuronide.

3 alpha-androstanediol glucuronide (3 alpha diolG) is a marker of peripheral tissue androgen metabolism. There are no previous data regarding complete paediatric reference ranges for 3 alpha diolG. In order to obtain reference values for 3 alpha diolG we have measured serum levels of 3 alpha diolG in 283 healthy children and adolescents, 146 boys and 137 girls, age 1 month to 20 years and 28 adults. A non-extraction, solid phase radioimmunoassay employing a polyclonal antiserum that is specific for 3 alpha diolG was used to measure serum 3 alpha diolG levels (intra assay variation 5.1-10.1%, inter assay variation 2.7-9.0%). There was a strong sex and age dependence (r = 0.8; p < 0.0001) of 3 alpha diolG levels throughout childhood and adolescence with males showing significantly higher levels of the androgen than females (p < 0.05). 3 alpha diolG serum levels (nmol/l +/- SD) correlated significantly with pubertal stage (p < 0.01). Interestingly, in 35 children with CAH serum 3 alpha diolG levels correlated well with clinical and metabolic status, i.e. 17OHP serum levels. In summary, we have established percentile curves for 3 alpha diolG levels in healthy children and adolescents. We hypothesize that on the basis of our reference values the single measurement of serum 3 alpha diolG could serve as a means to determine androgen status in children with disorders of puberty and sexual development.

Cloning and characterization of AFX, the gene that fuses to MLL in acute leukemias with a t(X;11)(q13;q23).

We report the cloning and characterization of the entire AFX gene which fuses to MLL in acute leukemias with a t(X;ll)(q13;q23). AFX consists of two exons and encodes for a protein of 501 amino acids. We found that normal B- and T-cells contain similar levels of AFX mRNA and that both the MLL/AFX as well as the AFX/MLL fusion transcripts are present in the cell line and the ANLL sample with a t(X;11)(q13;q23). The single intron of the AFX gene consists of 3706 nucleotides. It contains five simple sequence repeats with lengths of at least 12 bps, a chi-like octamer sequence (GCA/TGGA/TGG) and several immunoglobulin heptamer-like sequences (GATAGTG) that are distributed throughout the entire AFX intron sequence. In the KARPAS 45 cell line the breakpoints occur at nucleotides 2913/2914 of the AFX intron and at nucleotides 4900/4901 of the breakpoint cluster region of the MLL gene. The AFX protein belongs to the forkhead protein family. It is highly homologous to the human FKHR protein, the gene of which is disrupted by the t(2;13)(q35;q14), a chromosome rearrangement characteristic of alveolar rhabdomyosarcomas. It is noteworthy that the t(X;11)(q13;q23) in the KARPAS 45 cell line and in one acute nonlymphoblastic leukemia (ANLL) disrupts the forkhead domain of the AFX protein exactly at the same amino acids as does the t(2;13)(q35;q14) in case of the FKHR protein. In addition, the 5'-part of the AFX protein contains a conserved hexapeptide motif (QIYEWM) that is homologous to the functionally important conserved hexapeptide QIYPWM upstream of the homeobox domain in Hox proteins. This motif mediates the co-operative DNA binding of Pbx family members and Hox proteins and, therefore, plays an important role in physiologic and oncogenic processes. In acute leukemias with a t(X;11)(q13;q23), this hexapeptide motif is separated from the remaining forkhead domain within the AFX protein. The predicted amino acid sequence of AFX differs significantly from the partial AFX protein sequence published previously (Genes, Chromosomes and Cancer, 1994, 11, 79-84). This discrepancy can be explained by the occurrence of two sequencing errors in the earlier work at nucleotide number 783 and 844 (loss of a cytosine residue or guanosine residue, respectively) that lead to two reading frame shifts.

Short stature and low IGF-1 and IGFBP-3 despite normal growth hormone secretion in a 4 year-old girl with primary empty sella syndrome.

A 4.1 year-old girl presented with short stature, cleft lip and additional upper incisor. Magnetic resonance imaging showed an empty sella due to a hypoplastic anterior pituitary. IGF-I and IGFBP-3 were at and below the 1st percentile, respectively. In contrast, normal spontaneous growth hormone (GH) secretion (5.5-h nocturnal sampling) was observed and pharmacological provocation raised (GH to levels between 15.4 and 53 micrograms/l. GH-binding protein levels were normal (210 pM). GH therapy led to an increase of growth velocity from 4.5 to 10.8 cm/year and a normalization of IGF-I and IGFBP-3 levels. The findings may imply an abnormal GH secretion pattern or a bioinactive GH in our patient. The data indicate that measurements of IGF-1 and IGFBP-3 may be a more sensitive test for integrative GH activity than GH testing itself.