Severe Neonatal Metabolic Decompensation in Methylmalonic Acidemia Caused by CblD Defect

CblD disorder is an autosomal recessive, rare, heterogeneous disease with variable clinical presentations, depending on the nature and location of the MMADHC gene mutations. Mutations in MMADHC lead to three distinct phenotypes: cblD-MMA, cblD-HC, and cblD-MMA/HC. To date, 18 cblD patients have been reported. Six of them were affected by cblD-MMA, but only three had a known clinical history. One of these patients presented with a metabolic decompensation at 11 months; the second one, born prematurely, was diagnosed with cblD after being treated for intracranial hemorrhage, respiratory distress syndrome, necrotizing enterocolitis, and convulsions at birth; the third one was diagnosed at 5 years of age.Here we present a case of a cblD-MMA patient who had an acute neonatal onset with severe hyperammonemia requiring hemodiafiltration. To the best of our knowledge, this is the first cblD-MMA patient who presented acutely in the newborn period. He has developed well upon treatment with B12, carnitine, and hypoproteic diet. At present time, at the age of 7, he shows normal growth and cognitive development. Thus, it is likely that the aggressive treatment of this child with hemodiafiltration might have prevented him from long-term neurological sequelae. Overall, this case shows that even severe, neonatal-onset patients may display a vitamin B12-responsive MMA. Furthermore, it suggests that an early treatment with vitamins might be beneficial for patients presenting with neonatal-onset hyperammonemia regardless of the suspected disease and before receiving the biochemical diagnosis.

The Italian screening program for primary congenital hypothyroidism: actions to improve screening, diagnosis, follow-up, and surveillance

The Italian screening program for primary congenital hypothyroidism (CH) is an integrated system including neonatal screening, diagnosis, treatment, follow-up, and nationwide surveillance of the disease. The aim of the Italian screening program for CH is to identify not only babies with severe permanent CH (core target), but also babies with mild persistent and transient forms of CH who could have a benefit from an early replacement therapy (secondary target). In the last years, despite the important results obtained in terms of standardization of screening and follow-up procedures, it has become clear the need of optimizing the program in order to harmonize the screening strategy and the screening procedures among Regions, and to improve the diagnostic and therapeutic approach in all affected infants. On the basis of available guidelines, the experience of the Italian screening and clinical reference centers, and the knowledge derived from the nation-wide surveillance activity performed by the Italian National Registry of Infants with CH, the Italian Society for Pediatric Endocrinology and Diabetology together with the Italian Society for the Study of Metabolic Diseases and Neonatal Screening and the Italian National Institute of Health promoted actions aimed at improving diagnosis, treatment, follow-up and surveillance of CH in our country. In this paper the most important actions to improve the Italian screening program for CH are described.

Epilepsy and argininosuccinic aciduria

BACKGROUND

We have reviewed the occurrence of epilepsy in our patients with argininosuccinic aciduria (ASA) (OMIM 207900) and the possible relationship of late epilepsy to symptomatic seizures in the neonatal period, hyperammonaemia and treatments.

METHODS

We retrospectively analysed 11 ASA patients (8 neonatal onset and 3 late onset), 6 of whom had developed epilepsy.

RESULTS

Epilepsy in our sample was frequent (55 %). It developed after a seizure-free period from the onset of the metabolic disease and seizures were responsive to treatment in all cases. Arginine plasma levels were kept in the same range for the 2 groups of patients with and without epilepsy.

CONCLUSIONS

Although epilepsy is reported to be common among patients with ASA, very few long-term follow-up studies are available. The pathophysiological mechanism of epileptogenesis remains unclear. Neither hyperammonaemia nor acute symptomatic seizures at birth seem to be predictive of late epilepsy. Excessive arginine dosages as a cause of epilepsy could be reasonably excluded since our 3 late onset patients developed epilepsy before the diagnosis of ASA, at a time when they were likely to be arginine deficient. Arginine deficiency may not be excluded as cause of epilepsy, but further studies are needed to define its role.

Molecular and clinical features associated with CFTR gene rearrangements in Italian population: identification of a new duplication and recurrent deletions

Cystic fibrosis (CF) is mainly caused by small deletions or missense mutations in the CFTR gene. The CF mutation database lists more than 35 large rearrangements that may escape detection using polymerase chain reaction-base techniques. The Innogenetics assay, the denaturing high-performance liquid chromatography and sequencing screening showed a mutation detection rate of 92.6% in our population. We report here the results of multiplex ligation-dependent probe amplification (MLPA) screening for CFTR gene rearrangements, performed on the unidentified alleles of our CF patients. Our sample population consists of 692 non-related Italian CF patients (for a total of 1384 alleles), followed at CF Centres in the Lombardia Region. MLPA analysis was performed in 49 patients who still had one or two unidentified alleles (for a total of 52 unidentified alleles) after extensive analysis of CFTR gene. All patients who were studied had the classical form of CF. We characterized nine different deletions and a new duplication. The deletion of exons 22-23 (7/82) was the most frequent in our cohort. The search for deletion/duplications of the CFTR gene has made it possible to reach a 94.1% detection rate, with an improvement (1.6%) of the carrier detection rate in the Italian population.

Congenital hypothyroidism with gland in situ: diagnostic re-evaluation

In the past, most congenital hypothyroidism (CH) children with thyroid gland in situ were considered to be affected by hormonogenesis defect. Nowadays, the improved sensitivity of neonatal screening, novel insights into the pathogenic mechanisms and the advances of genetic analyses have reopened the discussion about the etiology of CH with thyroid in situ. We report the etiological re-evaluation of 31 children with thyroid in situ, who had been identified by the CH screening program. The purposes of this re-evaluation were: a) to investigate the definitive diagnosis and pathogenetic mechanism of CH with thyroid in situ in eligible children suspected of dyshormonogenetic defect and b) to verify the adequacy of the treatment schedules. Thirty out of 31 children were affected with permanent hypothyroidism and only one child was euthyroid at re-evaluation (transient CH). Thyroid hormone organification defects were present in less than half of the CH patients with thyroid in situ (13/30); a higher prevalence of partial defects of iodine organification than severe or complete forms was found. An inactivating TSH-receptor gene mutation was found in only one patient without iodine organification defect. Some questions remain unanswered concerning the adequacy of the schedules of treatment, particularly about the proper treatment of mild and borderline forms of CH.

Diagnosis of congenital cytomegalovirus infection by detection of viral DNA in dried blood spots

BACKGROUND

The reference method of cytomegalovirus (CMV) isolation from urine or saliva is not a feasible routine technique for all newborns, and laboratory diagnosis of this infection would be useful both for epidemiological purposes and to enable prompt institution of adequate measures to identify and correct late sequelae. Extraction and amplification of viral DNA from dried blood spots (DBS) collected from babies in the first days of life during routine screening for genetic and metabolic disorders has been proposed for the early diagnosis of viral congenital infections.

OBJECTIVES

To test the method for CMV DNA extraction from DBS and to evaluate the results obtained in newborns with and without a diagnosis of congenital infection based on viral isolation from urine and or saliva at birth.

STUDY DESIGN

DBS from Guthrie cards collected in babies who underwent virological tests for CMV infection were tested for CMV DNA by observers blinded to the virological results. DNA was extracted from DBS both in water and in cell culture medium according to Shibata et al. with minor modifications. The products of nested polymerase chain reactions (PCR) amplifying two regions in the IE1 and gp58 genes were detected by agarose gel electrophoresis. Strict control measures were adopted to avoid carryovers and contaminations.

RESULTS

DBS from the eight symptomatic and 11 asymptomatic congenitally infected babies were positive when extraction was performed in medium, whereas extraction in water failed to identify two of the asymptomatic cases. The results obtained with the two extraction methods agreed in the remaining cases; the 71 CMV negative control babies were negative and two out of 21 cases of supposed postnatal infection were diagnosed as congenital on the basis of a positive DBS. All positive cases were identified by gp58 PCR but only slightly over half of them by IE1 PCR. Extraction in medium was more efficient than in water.

CONCLUSIONS

The method of CMV DNA extraction in medium followed by amplification of the gp58 region showed 100% sensitivity and specificity compared with isolation in cell culture. Therefore, we propose this procedure to diagnose congenital CMV infection at birth and also later.

Screening for cystic fibrosis in newborn infants: results of a pilot programme based on a two tier protocol (IRT/DNA/IRT) in the Italian population

OBJECTIVE

To assess the performance of a two tier neonatal screening programme (IRT/DNA/IRT) for cystic fibrosis, based on immunoreactive trypsinogen (IRT) followed by direct cystic fibrosis transmembrane conductance regulator (CFTR) gene analysis (based on a panel of up to 31 mutations) in hypertrypsinaemic newborn infants and to compare it with a previous screening protocol.

SETTING

The study comprised all the newborn infants in the period 1 October 1998 to 31 December 1999 in the Lombardia region, north western Italy.

METHODS

The screening strategy consisted of an immunoreactive trypsinogen assay from dried blood spots, a polymerase chain reaction (PCR) followed by an oligonucleotide ligation assay (PCR-OLA), and a sequence code separation.

RESULTS

104 609 newborn infants were screened. 1457 hypertrypsinaemic infants (1.39%) were analysed with the PCR-OLA assay. 18 newborn homozygotes or compound heterozygotes for CFTR mutations were identified and referred to the cystic fibrosis (CF) centre at a mean age of 3 weeks. 125 infants presenting only one mutation were recalled for a sweat test: a diagnosis of CF was made in 13 infants, and parents of 112 neonates identified as carriers (1:13) received genetic counselling. The remaining 1314 hypertrypsinaemic newborn infants were recalled for IRT retesting and 177 were referred for a sweat test because the second IRT measurement was above the cut off value. Among this group a further two infants were diagnosed with CF (1.1%) leading to a CF prevalence of 1:3170.

CONCLUSIONS

This strategy resulted in an early and accurate diagnosis of CF. The IRT/DNA/IRT protocol with an OLA assay was shown to be useful in an Italian population with a genetic heterogeneity, leading to the identification of 94% of infants with CF.

Genetic and clinical features of false-negative infants in a neonatal screening programme for cystic fibrosis

A study was performed on the delayed diagnosis of cystic fibrosis (CF) in infants who had false-negative results in a neonatal screening programme. The genetic and clinical features of false-negative infants in this screening programme were assessed together with the efficiency of the screening procedure in the Lombardia region. In total, 774,687 newborns were screened using a two-step immunoreactive trypsinogen (IRT) (in the years 1990-1992), IRT/IRT + delF508 (1993-1998) or IRT/IRT + polymerase chain reaction (PCR) and oligonucleotide ligation assay (OLA) protocol (1998-1999). Out of 196 CF children born in the 10 y period 15 were false negative on screening (7.6%) and molecular analysis showed a high variability in the genotypes. The cystic fibrosis transmembrane regulator (CFTR) gene mutations identified were delF508, D1152H, R1066C, R334W, G542X, N1303K, F1052V, A120T, 3849 + 10kbC --> T, 2789 + 5G --> A, 5T-12TG and the novel mutation D110E. In three patients no mutation was identified after denaturing gradient gel electrophoresis of the majority of CFTR gene exons.

CONCLUSION

The clinical phenotypes of CF children diagnosed by their symptoms at different ages were very mild. None of them presented with a severe lung disease. The majority of them did not seem to have been damaged by the delayed diagnosis. The combination of IRT assay plus genotype analysis (1998-1999) appears to be a more reliable method of detecting CF than IRT measurement alone or combined with only the delF508 mutation.

CMV gB genotypes and outcome of vertical transmission: study on dried blood spots of congenitally infected babies

BACKGROUND

The role of the virulence of the infecting cytomegalovirus (CMV) strain in the transmission of the virus from mother to fetus and the outcome of the fetal infection has not received much attention yet. Molecular analysis of the gene coding for the surface glycoprotein B (gB) has been used to investigate the relationship between genotype and virulence in groups of immunosuppressed patients.

OBJECTIVES

(1) to assess the prevalence of different gB genotypes in babies with congenital CMV infection; (2) to investigate the possible relationship between genotype and severity of congenital CMV disease; (3) to evaluate the possibility of using dried blood on Guthrie cards (DBS) for genotyping.

STUDY DESIGN

CMV DNA was extracted from DBS and from urine/saliva samples collected in the first two weeks of life of 98 congenitally infected babies, half of which were symptomatic at birth. Genotyping was performed through RFLP analysis of the region corresponding to the cleavage site of the gB protein.

RESULTS

The most prevalent genotype was gB1 (42%) followed by gB3 (26%), gB2 (19%) and gB4 (13%). Rates of disease and CNS damages were higher among children infected by gB1 (35%, 17%) and gB3 (31%, 28%) than in those infected by gB2 and gB4 (20%, 17% and 13%, 15%, respectively). These differences however did not reach the statistical significance. The parallel typing of DBS and urine/saliva strains gave a full concordance of results.

CONCLUSIONS

All four major CMV gB genotypes (gB1-4) can cause a congenital infection but none seems to be associated to the development and the severity of disease. The possibility of using the neonatal DBS for genotyping opens a way to the examination of large numbers of cases of congenital CMV infection.

Cytomegalovirus DNA detection in Guthrie cards: a powerful tool for diagnosing congenital infection

BACKGROUND

A simple and reliable diagnosis of congenital cytomegalovirus infection is necessary both for clinical and epidemiological purposes. This could be accomplished through the demonstration of cytomegalovirus (CMV) DNA in blood spots (DBS) on Guthrie cards.

OBJECTIVES

(1) To assess the sensitivity and specificity of the method (DBS test) in diagnosing congenital CMV infection compared with viral isolation and (2) to evaluate the applications of the test to the late diagnosis of congenital CMV.

STUDY DESIGN

The method was tested on the cards of (1) 509 babies examined through viral isolation within their third week of life (72 positive cases) and (2) 191 children studied after 3 weeks of life (25 days to 5 years). Blood was eluted from Guthrie cards and heat extracted. The products of a nested polymerase chain reaction (PCR) amplifying one region in the CMV glycoprotein B (gB) gene were detected by agarose gel electrophoresis.

RESULTS

DBS test was positive in all 72 congenitally infected babies and in four of the 437 negative at cytomegalovirus isolation (sensitivity 100%, specificity 99%). Infection in 16 of the 92 infants with a late viral isolation was demonstrated to be congenital by the test, which also detected congenital infection in 18 of 83 children in whom viral culture was not performed (13 with and five without symptoms). Fifty-six additional control cases tested negative.

CONCLUSIONS

DBS test is a reliable assay for diagnosing congenital cytomegalovirus infection and could be used as an alternative to viral culture. It is able to reveal whether ascertained CMV infection is congenital or postnatal at an age when viral isolation is not able to do so. It can assess the role of risky procedures such as transfusion and it can ascertain the etiology of morbid conditions diagnosed late or of controversial origin.

Metabolic factors in the renal response to amino acid infusion

In order to investigate the renal effects of amino acids (AA) with different metabolic fate, we compared the changes in glomerular and tubular function, nitrogen metabolism and glucoregulatory hormones in 7 volunteers during two infusions, one of a complete solution of amino acids (MIX-AA), which included five AA electively metabolized at the splanchnic level, and the other of a solution containing only essential AA (EAA), which escape splanchnic metabolism. MIX-AA increased GFR and RPF (from 104 +/- 6 to 122 +/- 13 and from 488 +/- 46 to 572 +/- 34 ml/min/1.73 m2), stimulated splanchnic metabolism as demonstrated by rises in urinary urea excretion (from 20.7 +/- 2 to 30.6 +/- 7.5 mg/min/1.73 m2) and the plasma glucagon/insulin ratio (from 21.4 +/- 13 to 26.7 +/- 15), and caused increases in fractional excretion of AA, FeNa and free-water clearance. During MIX-AA infusion significant correlations were observed between the individual values of GFR and the urea excretion rate (r = 0.66), and between GFR modifications (DeltaGFR) and the plasma glucagon/plasma insulin ratio (r = 0.40). No change in renal function, urea excretion and the glucagon/insulin ratio was observed with EAA. An intermediate splanchnic step (increased plasma glucagon/insulin ratio and ureagenesis) seems necessary in the pathway leading to the nonessential AA-induced rise in GFR; this might stimulate an ultimate intrarenal pathway (possibly involving the diluting segment) via a still undefined mechanism.

Rapid reversal of dilated cardiomyopathy following removal of neuroblastoma

Reported is a child with dilated cardiomyopathy, in whom medical therapy resulted in a mild improvement of cardiac function. Metabolic studies suggested the presence of a catecholamine-secreting tumour; and an adrenal neuroblastoma was identified and surgically removed. Following surgery, there was progressive and complete normalization of cardiac function. Although very rare, neurogenic tumours may be involved in the development of a dilated cardiomyopathy in the infant and child.

Hypotonic saline infusion alters the renal response to amino acids in men

We investigated the effects of hypotonic saline-induced modifications of extracellular volume and sodium handling on the renal and metabolic response to amino acids (AA). Renal hemodynamics (Inutest, p-aminohippurate clearance), plasma AA, and glucagon levels, as well as urea and sodium excretion, were studied in seven adult volunteers infused for 2 h, on six separate occasions, according to the following protocols: 1) high-AA solution (300 mg. min-1. 1.73 m-2); 2) low-AA solution (150 mg. min-1. 1.73 m-2); 3) low AA + 2,000 ml/1.73 m2 of 0.23% saline solution; 4) high AA + 0. 23% saline; 5) high AA + 0.45% saline; and 6) 0.45% saline alone. The glomerular filtration rate (GFR) rise induced by the high-AA solution was similar to that induced by the low-AA solution (DeltaGFR = +24 +/- 6 and +20.2 +/- 7 ml. min-1. 1.73 m-2, respectively), whereas the plasma AA and glucagon levels and urea excretion rate increases were related to AA dose. The addition of 0. 23% saline to the low-AA solution and of 0.45% saline to the high-AA solution blunted the renal hemodynamic response (DeltaGFR = +6.6 +/- 10.1 and +11.4 +/- 8.3 ml. min-1. 1.73 m-2, respectively) without modifying the pattern of plasma AA and glucagon levels and urea excretion observed with the AA infusion alone. Urinary sodium excretion increased from baseline with each protocol and rose even further when saline was added to AA. A negative correlation (r = -0. 38, P < 0.05) was found between the changes from basal values in GFR and those in sodium excretion rate with high-AA infusion at different levels of sodium concentration. These data suggest that AA-induced hyperfiltration might be blunted by hypotonic saline infusion, possibly through an acute modification of renal sodium handling and extracellular volume.

Maternal concentrations and fetal-maternal concentration differences of plasma amino acids in normal and intrauterine growth-restricted pregnancies

OBJECTIVES

Our purpose was to determine whether maternal amino acid concentration changes during gestation in pregnancies with intrauterine growth restriction as in normal pregnancies and to verify whether these changes are related to changes in fetal-maternal differences.

STUDY DESIGN

Amino acid concentrations were measured in 5 nonpregnant women, in 11 second-trimester and 10 third-trimester pregnant women with appropriate-for-gestational-age fetuses, and in 23 pregnant women with intrauterine growth restriction. Umbilical venous amino acids were measured at the time of fetal blood sampling. The severity of intrauterine growth restriction was assessed by Doppler velocimetry and fetal heart rate and by evaluation of oxygenation and acid-base balance.

RESULTS

In normal pregnant women the maternal concentration of most amino acids was significantly lower in both the second and third trimesters compared with nonpregnant women. In intrauterine growth restriction the maternal concentrations of most essential amino acids were significantly higher than in appropriate-for-gestational-age pregnancies. This observation, coupled with lower fetal amino acid concentrations in intrauterine growth restriction, leads to significantly lower fetal-maternal differences.

CONCLUSIONS

Normal pregnant women have a significant decrease in amino acid concentrations compared with nonpregnant women, whereas in intrauterine growth restriction maternal amino acids are reduced less, Significantly lower fetal-maternal concentration differences are present in intrauterine growth restriction, independent of the degree of severity.

[Is the assessment of prothrombin fragment F1+2 for monitoring of heparin therapy in patients with deep vein thrombosis useful?]

Prothrombin fragments (F1+2) can be used to monitor oral anticoagulation; their generation is also suppressed by heparin. We studied the course of F1+2, aPTT, heparin doses administered and heparin concentrations, as well as prothrombin time, during the first 7 days of heparin therapy (target aPTT 70 s) and overlapping oral anticoagulation (target INR 2-3) in 26 patients routinely treated for deep venous thrombosis (deep venous thrombosis +/- pulmonary embolism, 23 patients) or pulmonary embolism with a history of recurring deep venous thrombosis (3 patients). Although we found significant suppression of F1+2 between all pre- and post-treatment values, a transient, significant increase was seen on days 2-4. The amount of heparin given was stable from day 1-5; the fact of a transient increase in F1+2 might thus indicate that heparin doses routinely used are too low for the treatment of hypercoagulability in deep venous thrombosis in patients. We also found a decrease in heparin concentration on day 2, which may be explicable by changed pharmacokinetics of heparin in individuals with deep venous thrombosis. In conclusion, F1+2 may be useful for monitoring heparin treatment and oral anticoagulation in deep venous thrombosis patients from a laboratory point of view. However, larger studies are necessary to confirm these results. It remains to be clarified whether monitoring of anticoagulation by molecular markers might improve therapy of deep venous thrombosis. Such studies are in progress.

Hyperammoniemic coma in an adolescent girl: an unusual case of ornithine transcarbamylase deficiency

Ornithine transcarbamylase deficiency (OTCD) is caused by an alteration of urea synthesis, linked with partial modification of the X-chromosome, whose clinical manifestations are: lethargy, nausea, vomiting and cerebral edema. While in newborn males OTCD presents with hyperammoniemia leading to cerebral palsy with profound neurological impairment and eventually death, in women who are healthy carriers, it is possible to detect the disorder only through specific tests, since heterozygote women are rarely symptomatic. We describe the case of a young woman admitted to the hospital after an episode of mental confusion with vomiting and psychomotor restlessness, which had previously occurred several times during the premenstruum and lasted a few hours. A 2 day history of stupor made admission mandatory. Tests carried out during the hospital stay showed marked hyperammoniemia and unconjugated hyperbilirubinemia, marked cerebral edema documented by a CT scan. Liver biopsy and CSF test were normal. Screening of plasma and urinary aminoacids, level of orotic acid in the urine and OTC activity in the liver, confirmed the diagnosis of OTCD. The possibility of early diagnosis and therapy of a disease which otherwise leads to death, emphasizes the importance of precise evaluation of a possible organic cause of anorexia and behaviour disorders in young women.

Plasma amino acid concentration changes during total parental nutrition in critically ill patients

In 16 critically ill patients with full-blown stress reaction and without severe organ failure, we studied the kinetics of the arterial plasma amino acid (aa) profile during the first 48 h of total parenteral nutrition (TPN) in order to assess the time necessary to reach the steady-state condition during infusion. Each patient was treated with one of three different amino acid solutions giving, with the same nitrogen load, different intakes of individual amino acids. We found four different responses to the administered amino acids. Some amino acids showed a different trend depending on the dose given. At lower doses a steady state was achieved sooner. Plasma levels of amino acids not supplied in the TPN were unaffected or decreased, achieving a steady state at various times during the study period. We conclude that, in critically ill patients, stable arterial plasma amino acid concentrations are obtained within 24 h of starting TPN. In such patients, valid studies of the effect of amino acid solutions may therefore be carried out over short periods of time, thereby minimizing errors due to a fluctuating and unstable clinical state.

Fetal amino acids in normal pregnancies and in pregnancies complicated by intrauterine growth retardation

Plasma amino acid concentrations were measured in normal (AGA) and intrauterine growth retarded (IUGR) percutaneous umbilical blood sampling (PUBS) performed for prenatal diagnosis or at elective cesarean section. IUGR fetuses present significantly lower concentrations of most amino acids, with a significant reduction of the umbilical veno-arterial difference for total alpha-amino nitrogen. These findings are present early in growth retarded fetuses and may be potentially responsible for the growth retardation.

[Recovery after serious mushroom poisoning (grade IV encephalopathy) with intensive care support and without liver transplantation. Clinical case]

Despite consistent improvement in its treatment, amatoxin poisoning still extolls an elevated overall mortality, ranging between 10 and 15%, which approaches 100% when severe (grade 3-4 encephalopathy) hepatic failure supervened. Therefore, the proper treatment of intoxication by amatoxin containing mushrooms, and particularly of its complications, remains a challenge in emergency medicine. Klein and coworkers reviewed the role of liver transplantation in amatoxin poisoning as a useful therapeutic tool for patients with severe impairment of liver function. Their indication for intervention is the presence of any of the following signs: grade 2 encephalopathy or higher; prothrombin time twice than normal, despite fresh frozen plasma infusion; hypoglycemia requiring hypertonic glucose infusion; hyperbilirubinemia (greater than 25 mg/dl). During the past autumn two patients with fulminant hepatic failure due to amatoxin poisoning were referred to our institutions as candidates for liver transplantation, since both satisfied Klein's criteria. However, due to shortage of organ donors it was impossible to transplant them over the following days. Despite they did not receive liver transplantation, both patients wakened from coma, their liver function improved, and they recovered from terminal amatoxin poisoning. After one year, both patients are long-term survivors, in good health and without any sequelae either in brain or liver function.

Plasma and erythrocyte amino acids in mother and fetus

Plasma (P) and whole blood (WB) amino acid concentrations were measured in arterial and venous blood of 9 mothers and their fetuses at elective cesarean section and compared to values obtained in 5 normal nonpregnant women. Erythrocyte (E) amino acid concentrations were calculated from P and WB concentrations. E/P ratios were significantly greater than 1.0 in all groups studied. Alanine, glycine, and serine presented E/P ratios significantly higher in pregnant women than in control nonpregnant women. Fetuses presented significantly lower E/P ratios for lysine than pregnant and nonpregnant women. Uterine arteriovenous amino acid differences were not significantly different from zero in both plasma and erythrocytes. Umbilical venous-arterial differences were significantly positive for most essential amino acids in plasma, whereas they were not significantly different from zero in erythrocytes. This finding suggests that erythrocytes do not play a major role in the transfer of amino acids from the placenta to the fetus.

Umbilical amino acid concentrations in normal and growth-retarded fetuses sampled in utero by cordocentesis

Fetal plasma amino acid concentrations were obtained by cordocentesis at midgestation in 11 normal (appropriate for gestational age) fetuses and at late gestation in 12 small-for-gestational-age fetuses, and at cesarean section in 14 normal term infants. In normal fetuses total molar amino acid concentrations and fetal/maternal total molar concentration ratios did not change significantly between the second and third trimesters. Fetal and maternal concentrations of most amino acids were significantly correlated at both midgestation and late gestation. Small-for-gestational-age fetuses had significantly lower concentrations of total alpha-aminonitrogen; this was mainly because of a reduction of the branched chain amino acids valine, leucine, and isoleucine, and of lysine and serine. Maternal arterial concentrations of phenylalanine, arginine, histidine, and alanine were elevated in small-for-gestational-age pregnancies. Thus there are only minor changes in amino acid concentrations between midgestation and late gestation in normal fetuses with a constant fetal/maternal ratio. In small-for-gestational-age infants a significant reduction in alpha-aminonitrogen and in most essential amino acids was demonstrable in utero weeks before delivery.

Serum levels of immunoreactive trypsin during development: comparison with levels of lipase and amylase

In order to obtain additional information on serum pancreatic enzyme levels during development, we have measured immunoreactive trypsin (IRT), immunoreactive lipase (IRL), and total amylase in paired fetal and maternal sera. Samples were obtained during early gestation (14-21 week of gestation) and at the time of normal delivery. IRT levels were lower in maternal sera as compared to paired fetal and neonatal (p less than 0.005); conversely, IRL and amylase, although present in measurable concentrations, were significantly lower in fetal and neonatal sera than in the maternal (p less than 0.001). We also serially monitored serum pancreatic enzyme levels in a group of premature infants during the first 10 days of life. Concentrations of IRT showed a significant increase over time (p less than 0.05) and those of IRL remained stable while amylase levels decreased sharply, suggesting possible maternal origin of this enzyme. Serum concentrations of the three pancreatic enzymes in newborns at term (second day of life) were higher than in infants aged 0.5-6 months; however, only IRT levels were above the normal range for adults. Beyond the neonatal period, IRT levels were stable and comparable to adults, whereas amylase and IRL levels were very low in infants younger than 6 months and increased significantly with age (p less than 0.001). These data seem to indicate that "physiologic hypertrypsinemia" occurs early during development and may be accentuated by postnatal events. They provide an indirect indication of both early fetal production of trypsinogen and possible placental transfer of pancreatic enzymes from the maternal circulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Umbilical amino acid concentrations in appropriate and small for gestational age infants: a biochemical difference present in utero

Plasma amino acid concentrations were determined in 28 pregnant women and their infants at term. Samples were obtained from 17 appropriate for gestational age and eight small for gestational age infants at cesarean section, while three small for gestational age fetuses were studied in utero by transabdominal cord sampling by means of ultrasonic guidance. Small for gestational age fetuses have significantly lower concentrations of alpha-aminonitrogen, compared with those of appropriate for gestational age fetuses, in both the umbilical artery and vein. Most of the difference is accounted for by the branched chain amino acids valine, leucine, and isoleucine. In contrast, hydroxyproline concentration is significantly higher in both the umbilical artery and vein of small for gestational age fetuses. The sum of the branched chain amino acid concentrations in the umbilical vein is directly related to maternal arterial values in both appropriate for gestational age and small for gestational age fetuses. Maternal arterial concentrations were slightly lower in small for gestational age fetuses and the regression analysis of umbilical venous versus maternal arterial branched chain amino acid concentrations was significantly different for small for gestational age and appropriate for gestational age infants. Umbilical venoarterial concentration differences in normal fetuses are significantly positive for most essential amino acids and for total alpha-aminonitrogen. In contrast, these differences were significant only for four essential amino acids in small for gestational age infants, while the total alpha-aminonitrogen venoarterial difference was not significant. The data obtained by transabdominal cord sampling from relatively undisturbed fetuses were in agreement with the data obtained at cesarean section; this information suggests that these differences between small for gestational age and appropriate for gestational age infants reflected steady-state conditions.

Effect of taurine supplementation on fat and bile acid absorption in patients with cystic fibrosis

Eleven children with cystic fibrosis (CF) and pancreatic insufficiency were given supplementation with taurine (30-40 mg/kg/day) for 2 months, while taking their usual dosage of enzymatic therapy. One patient dropped out of the study because she developed severe constipation. In the other 10 patients, urinary taurine excretion (88 +/- 30.1 mg/m2s.a./24 h) was similar to that of controls (86.2 +/- 6 mg/m2s.a./24 h) before taurine and increased markedly after supplementation (618.2 +/- 79.97 mg/m2s.a./24 h), indicating efficient intestinal absorption. Their coefficient of fat absorption was 81.2 +/- 2.3% and increased significantly after taurine (91.3 +/- 1.13%; p less than 0.01); the area under the curve of plasma triglyceride postprandial levels (1 +/- 0.1 mg X min/ml) also increased significantly after taurine (1.4 +/- 0.3 mg X min/ml; p less than 0.05), showing values very similar to those of controls. Conversely, no change was observed in the serum postprandial levels of glycocholic acid: the maximum postprandial peak before (1.2 +/- 0.3 mumol/l) and after taurine (1 +/- 0.1 mumol/l) remained significantly lower than in controls (2.4 +/- 0.3 mumol/l); p less than 0.01 and p less than 0.001, respectively. Mean total fecal bile acid (BA) excretion was 10.24 +/- 2.15 mg/kg/day before taurine and 12.8 +/- 4.27 mg/kg/day after taurine (normal pediatric values, 2.91 +/- 1.1 mg/kg/day); however, in the individual patients we found a variable trend, four of them showing a net increase in fecal BA excretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Proximal tubular function and hyperfiltration during amino acid infusion in man

The relations between renal hemodynamics (Inutest, CPAH) and sodium segmental handling (sodium distal delivery, distal reabsorption, and fractional excretion) were studied in 9 healthy adults infused with an isotonic amino acid solution and in 6 subjects infused with 0.9% saline for 3 h at 0.2 ml/min/kg. During all tests maximal water diuresis was induced and maintained to effect analysis of sodium segmental transport. Both types of infusion produced a similar expansion of extracellular volume (weight increase, hematocrit fall, suppressed plasma renin activity and plasma aldosterone). The amino acid infusion increased the glomerular filtration rate (GFR) and renal blood flow without modifying the filtration fraction. With saline no hemodynamic modifications were observed. The expansion with saline depressed proximal and distal sodium reabsorption whereas during amino acid infusion sodium distal delivery was unaltered and the significantly increased sodium fractional excretion was sustained only by depressed distal reabsorption. Therefore, in parallel with the GFR increase, closely dependent on renal vasodilatation, the well-known stimulation of sodium cotransport by amino acids is able to antagonize the effects of expansion on the proximal sodium reabsorption. An explanation of glomerular hyperfiltration based on a primary metabolic stimulation of the proximal tubular function is suggested.