[Flexible programs and advanced training for rheumatological patient education]

In two research projects, rheumatological patient education programmes were updated. The first step was to develop an expert consented framework for all rheumatological patient education programmes. From this, curricula and working materials for rheumatoid arthritis (RA) and axial spondyloarthritis (AS) were derived and two exemplary patient education manuals developed. A randomized controlled trail was designed for the five-hour RA basic education program. Finally, existing train-the-trainer training courses were adapted for these patient education programmes.

Inhibitor-Immunology-Study

The development of inhibitors is one of the most important complications of replacement therapy in haemophilia, affecting mortality and morbidity. Inhibitor development is based on complex immunological factors. Cytokines and their receptors, T-cell receptors, and the Major Histocompatibility Complex may play important roles in the development of inhibitors. Earlier studies showed non significant associations between HLA class and inhibitor development. Later studies found an increased risk of inhibitor development if there was a combination between certain factor VIII mutations and HLA antigens. We performed HLA typing in 50 patients with haemophilia A in an effort to find associations with inhibitor development. Results: 25 patients had developed an inhibitor (11 low titre, 14 high titre), and 25 never had. In logistic regression analysis, HLA-A 34, DRB1 0405, DRB1 1301 seemed to be involved in inhibitor development and HLA-A 30, B 13, B15, B 57, Cw 12, DQB1 0303, DPB1 0201 protection against inhibitor development. In our patients, the HLA-associations with inhibitor development were different from those in previous publications.

Acute effects of short-chain alkylglycerols on blood-brain barrier properties of cultured brain endothelial cells

BACKGROUND AND PURPOSE

The blood-brain barrier (BBB) restricts drug penetration to the brain preventing effective treatment of patients suffering from brain tumours. Intra-arterial injection of short-chain alkylglycerols (AGs) opens the BBB and increases delivery of molecules to rodent brain parenchyma in vivo. The mechanism underlying AG-mediated modification of BBB permeability is still unknown. Here, we have tested the effects of AGs on barrier properties of cultured brain microvascular endothelial cells.

EXPERIMENTAL APPROACH

The effects of two AGs, 1-O-pentylglycerol and 2-O-hexyldiglycerol were examined using an in vitro BBB model consisting of primary cultures of rat brain endothelial cells, co-cultured with rat cerebral glial cells. Integrity of the paracellular, tight junction-based, permeation route was analysed by functional assays, immunostaining for junctional proteins, freeze-fracture electron microscopy, and analysis of claudin-claudin trans-interactions.

KEY RESULTS

AG treatment (5 min) reversibly reduced transendothelial electrical resistance and increased BBB permeability for fluorescein accompanied by changes in cell morphology and immunostaining for claudin-5 and β-catenin. These short-term changes were not accompanied by alterations of inter-endothelial tight junction strand complexity or the trans-interaction of claudin-5.

CONCLUSION AND IMPLICATIONS

AG-mediated increase in brain endothelial paracellular permeability was short, reversible and did not affect tight junction strand complexity. Redistribution of junctional proteins and alterations in the cell shape indicate the involvement of the cytoskeleton in the action of AGs. These data confirm the results from in vivo studies in rodents characterizing AGs as adjuvants that transiently open the BBB.

[Multimorbidity in elderly rheumatic patients part 2]

While diseases, such as cardiovascular diseases and osteoporosis in the elderly are categorized as comorbidities of rheumatoid arthritis, elderly rheumatic patients are often additionally affected by thyroid dysfunctions and diabetes mellitus type 2, so that the risk of multimorbidity (coexistence of at least two chronic and/or acute diseases) will increase significantly in elderly patients already suffering from systemic rheumatic diseases. Restricted cognition, adherence or compliance may additionally complicate the treatment of elderly rheumatic patients. Furthermore, the pharmacokinetics of the elderly is another challenging task. Referring to selected aspects of geriatric pharmacotherapy, the use of certain substance classes is described in this context.

Inhibitor-Immunology-Study. Different HLA-types seem to be involved in the inhibitor development in haemophilia A

The development of inhibitors is one of the most important complications of replacement therapy in haemophilia, affecting mortality and morbidity. Inhibitor development is based on complex immunological factors. Cytokines and their receptors, T-cell receptors, and the Major Histocompatibility Complex may play important roles in the development of inhibitors. Earlier studies showed non significant associations between HLA class and inhibitor development. Later studies found an increased risk of inhibitor development if there was a combination between certain factor VIII mutations and HLA antigens. We performed HLA typing in 50 patients with haemophilia A in an effort to find associations with inhibitor development.

RESULTS

25 patients had developed an inhibitor (11 low titre, 14 high titre), and 25 never had. In logistic regression analysis, HLA-A 34, DRB1 0405, DRB1 1301 seemed to be involved in inhibitor development and HLA-A 30, B 13, B15, B 57, Cw 12, DQB1 0303, DPB1 0201 protection against inhibitor development. In our patients, the HLA-associations with inhibitor development were different from those in previous publications.

[Risk factors for perioperative complications in renal surgery for Wilms' tumor]

BACKGROUND

There is controversy about preoperative chemotherapy in the treatment of Wilms' tumor. The perioperative morbidity plays a key role in this discussion. Therefore, risk factors of perioperative complications were analysed in our series of patients with Wilms' tumor with a special focus on the effects of preoperative chemotherapy.

PATIENTS AND METHODS

Case histories of 37 patients [mean age 3.9 (range: 0.6 - 14) years] were retrospectively analysed concerning follow-up, clinical and histopathological stage, size of the primary tumor, as well as duration and extent of preoperative chemotherapy.

RESULTS

35 patients underwent radical nephrectomy, 2 patients had organ-sparing surgery because of bilateral involvement. The mean maximal tumor diameter was 9.5 cm (range: 4 - 24 cm). 11/37 patients had no or shortened preoperative chemotherapy. 6/37 patients (16.2 %) had perioperative complications. There was one intraoperative tumor rupture, 4 small bowel obstructions, 1 pancreatitis. All complications occurred in patients of clinical stages III and IV, maximal tumor diameter > 10 cm after unusually extended operative procedures. 4 patients showed only poor response to preoperative chemotherapy. Patients with doxorubicin pre-treatment showed a higher risk of postoperative small bowel obstruction.

CONCLUSIONS

The risk of perioperative complications was correlated with the local extent of the primary tumor and was higher with those requiring more extensive surgical interventions. The influence of preoperative chemotherapy on the complications rate is inconstant. Considering a good response of the primary tumor, the complication rate will be decreased. However, the comorbidity of more intense preoperative chemotherapy in patients of stage IV may contribute to a higher risk of surgical complications.

Downregulation of Apaf-1 and caspase-3 by RNA interference in human glioma cells: Consequences for erucylphosphocholine-induced apoptosis

Erucylphosphocholine (ErPC) exerts strong anticancer activity in vivo and in vitroand induces apoptosis even in chemoresistant glioma cell lines. We investigated the contribution of Apaf-1 and caspase-3 to the apoptotic response to ErPC using RNA interference (RNAi) in human glioblastoma cells. We could demonstrate that human glioma cell lines are susceptible to RNAi. Apaf-1 and caspase-3 are amenable to specific small interfering RNA (siRNA)-induced degradation resulting in a reduction of protein levels to 8-33% (Apaf-1) and to 30-50% (caspase-3). Transfection of siRNA directed to Apaf-1 and caspase-3 specifically reduced caspase-3 processing induced by ErPC treatment and yielded a reduction in cells that undergo ErPC-induced apoptosis to 17-33% (Apaf-1) and to 38-50% (caspase-3). The caspase-3 siRNA experiments were corroborated in caspase-3-deficient and -reconstituted MCF-7 breast cancer cells. Survival assays and morphological observations revealed that caspase-3 reconstitution significantly sensitized MCF-7 cells to ErPC. Exploring the caspase cascade responsible for ErPC-induced apoptosis MCF-7 cells provided evidence that caspase-3 is required for the activation of caspases-2, -6 and -8 and also participates in a feedback amplification loop. Our results provide evidence that Apaf-1 and caspase-3 are major determinants of ErPC-induced apoptosis and the possible use of ErPC in a clinical setting is discussed.

Induction of differentiation and tetraploidy by long-term treatment of C6 rat glioma cells with erucylphosphocholine

Induction of differentiation represents a promising concept for chemotherapy of malignant gliomas, which are often refractory even to the combined treatment with surgery, irradiation and chemotherapy. Since anti-neoplastic alkylphosphocholines can induce differentiation of leukemic cell lines, the effects of the intravenously applicable alkylphosphocholine-derivative erucylphosphocholine (ErPC) on proliferation, morphology and differentiation of the rat glioma cell line C6 was examined in vitro. Short-term exposure to ErPC induced accumulation of the cells in the G2/M-phase of the cell cycle and apoptotic cell death. In contrast, continuous exposure of C6 rat glioma cells to sublethal ErPC doses (30 and 50 microM) caused both the formation of a slower growing tetraploid cell population and astrocytic differentiation. No resistance to in vivo obtainable ErPC concentrations was observed during this treatment. We conclude that ErPC-induced differentiation might be beneficial for a long-term adjuvant chemotherapy of low grade glioma.

Erucylphosphocholine-induced apoptosis in chemoresistant glioblastoma cell lines: involvement of caspase activation and mitochondrial alterations

Intrinsic chemoresistance constitutes a major problem in the therapy of malignant gliomas. In vitro experiments with four astrocytoma/glioblastoma (AC/GBM) cell lines revealed that the chemoresistance of two cell lines, A172 and T98G, to cisplatin and etoposide was due to resistance to drug-induced apoptosis. In contrast, all the AC/GBM cell lines tested were sensitive to treatment with the lipophilic ether lipid erucylphosphocholine, ErPC. ErPC-induced apoptosis was independent of wild-type p53-signaling and triggering of the CD95/CD95 ligand (CD95L) system. Inhibition of protein and RNA synthesis by cycloheximide and actinomycin D did not abrogate ErPC-induced apoptosis. However, expression of members of the bcl-2 protein family was modulated during ErPC treatment. Activation of caspase 3 and mitochondrial alterations were central to ErPC-induced apoptosis. We conclude that ErPC-induced activation of the mitochondrial pathway enables cell death in the chemoresistant AC/GBM cells.

Pharmacokinetics of cisplatin and relation to nephrotoxicity in paediatric patients

BACKGROUND

Cisplatin is a highly effective and frequently used drug in the chemotherapy of solid tumours in children, but only limited data are available on the pharmacokinetics of cisplatin and its associated nephrotoxicity in paediatric patients.

METHODS

We investigated the pharmacokinetics of free platinum (Pt) in 12 children (25 courses) receiving cisplatin (75-120 mg/m2) either as a continuous 72-h infusion, prolonged single 6-h infusion or repetitive 1-h infusions. Plasma and urinary Pt concentrations were analysed using atomic absorption spectroscopy. Cisplatin-induced nephrotoxicity was determined using creatinine clearance and several glomerular and tubular marker proteins.

RESULTS

Using a two-compartment model the pharmacokinetic parameters for free Pt were: initial half-life 21.6 +/- 9.6 min, terminal half-life 25.9 +/- 16.2 h, area under the plasma concentration-time curve (AUC) 13.5 +/- 4.97 (microg/ml) x h/(100 mg/m2) and cumulative renal elimination(infinity) 41.7 +/- 6.6% of dose. Higher cisplatin delivery rates led to higher peak concentrations of free Pt in plasma and urine and to lower cumulative renal Pt elimination (P < 0.01). During all courses, increases of urinary albumin and alpha1-microglobulin excretion were documented. The creatinine clearance decreased significantly to 70% of baseline values. Correlations were found between both peak free Pt concentrations in plasma and in urine and the maximum of urinary excretions of albumin and of N-acetyl-beta-D-glucosaminidase and the nadir of the glomerular filtration rate (P < 0.05).

CONCLUSIONS

With respect to nephrotoxicity, long-term infusions of cisplatin seem to be preferable over intermittent bolus administration in paediatric patients. The best predictive pharmacokinetic parameters for cisplatin-associated nephrotoxicity in children are peak free Pt concentrations in plasma and urine.

[Cranial irradiation induces premature activation of the gonadotropin-releasing-hormone]

BACKGROUND

CNS-irradiation in prepubertal children with leukemia or brain tumors can lead to precocious or in high doses to delayed puberty. The underlying mechanisms of these disorders are unknown.

METHODS

A new animal model of experimentally induced pubertal disorders by cranial irradiation has been developed. In infantile or juvenile (12 - 23 days old) female rats precocious or delayed puberty have been induced by selective cranial Co60-irradiation (4 - 18 Gy). At age of 32 - 38 days or 3 months relevant hormone parameters have been studied basal and after stimulated conditions.

RESULTS

Low radiation doses (5 or 6 Gy) led to accelerated onset of puberty as well as elevated LH- and estradiol levels. High radiation doses (9 - 18 Gy) caused retardation of sexual development, lower gonadotropin levels and growth retardation associated with growth hormone deficiency. After cranial irradiation with 5 Gy the release rates of the inhibitory neurotransmitter gamma-aminobutyric-acid (GABA) from hypothalamic explants were significantly lower (p < 0,05). The gonadotropin-releasing-hormone (GnRH) expression in the hypothalamic preoptic area of irradiated animals (5 Gy) was significantly higher than in controls (p < 0,05).

CONCLUSION

The GnRH-pulse generator is very radiosensitive as low dose irradiation causes precocious puberty, whereas high dose irradiation is associated with delayed sexual maturation. Radiation induced precocious puberty might be caused by damage to inhibitory GABAergic neurons leading to desinhibition and premature activation of GnRH neurons. Our animal model of cranial irradiation seems to be suitable to study neurotransmitter disorders, molecular mechanisms and potential preventive intervention of radiation induced pubertal changes.

Cisplatin nephrotoxicity in children after continuous 72-h and 3x1-h infusions

Little is known about the association between the rate of cisplatin administration and the severity of cisplatin-induced renal damage in children. The purpose of this study was to compare severity and reversibility of renal damage in children after continuous and repetitive bolus administration of cisplatin and to correlate these data with pharmacokinetic parameters. Study subjects included six children (ten courses) receiving cisplatin as 1-h bolus infusions on three consecutive days (3x40 mg/m2) and four children (eight courses) receiving 72-h continuous infusions (120 mg/m2). In all courses, signs of glomerular and tubular damage were seen, as evidenced by elevated urinary excretion of alpha1-microglobulin, albumin and N-acetyl-beta-D-glucosaminidase and decreased glomerular filtration rate (GFR). Comparing the two infusion regimens, the 1-h bolus administration of cisplatin was followed by significantly higher peak free platinum concentrations in plasma and urine (P<0.001), resulting in lower nadirs of the GFR (P<0.005). Correlations were found between both peak free platinum concentrations in plasma and urine and maxima of urinary albumin and N-acetyl-beta-D-glucosaminidase excretion. Within 12 months after completion of cisplatin therapy, children in the 1-h bolus group had recovered only partially from subclinical nephrotoxicity, with five out of six showing pathological proteinuria. The results provide clear evidence that long-term ciplatin infusions are less nephrotoxic than repetitive bolus infusions.

Autoregulation of the gonadotropin-releasing hormone (GnRH) system during puberty: effects of antagonistic versus agonistic GnRH analogs in a female rat model

To address whether gonadotropin-releasing hormone (GnRH) regulates its own expression and the expression of its receptor in the hypothalamus and ovary, we treated five groups of prepubertal/peripubertal female rats from postnatal days 25-36 with either the GnRH agonist triptorelin (TRIP) or the GnRH antagonist cetrorelix (CET), each 10 or 100 microgram/day, or a placebo. We compared their effects regarding pubertal development, serum gonadotropins and the expression of GnRH and GnRH-receptor in the hypothalamus, pituitary, ovary and uterus. Onset of puberty was determined by vaginal opening, and expression levels of GnRH and GnRH-receptor were determined using either quantitative real-time PCR or competitive RT-PCR. Onset of puberty was retarded by both analogs but CET (100 microgram/day) inhibited while TRIP (10 and 100 microgram/day) stimulated serum gonadotropins (P<0.05). The expression of GnRH in the preoptic area did not show significant differences among the treatment groups but ovarian GnRH mRNA levels were significantly stimulated by CET (100 microgram/day). GnRH mRNA could not be detected in the uterus by either real-time PCR or competetive RT-PCR. The GnRH-receptor expression in the hypothalamus (preoptic area and mediobasal hypothalamus) did not vary among any of the groups, whereas in the pituitary GnRH-receptor mRNA levels were stimulated by TRIP (10 microgram/day) but inhibited by CET (100 microgram/day). In contrast, in the ovary GnRH-receptor mRNA levels were inhibited by both TRIP (100 microgram/day) and CET (100 microgram/day). Interestingly, the GnRH-receptor was even expressed in the uterus where it was strongly stimulated by both CET and TRIP in a dose-related manner. This shows that in addition to their different pituitary effects, the GnRH analogs cetrorelix and triptorelin exert different actions at the hypothalamic, ovarian and uterine level. This study also demonstrates an organ-specific regulation of GnRH and GnRH-receptor gene expression which is likely part of a local autoregulatory system. We conclude that the ovarian and uterine effects of GnRH analogs must be considered in addition to their known pituitary effects when deciding which GnRH analog is most suitable for treating precocious puberty.

Molecular basis of recessive congenital methemoglobinemia, types I and II: Exon skipping and three novel missense mutations in the NADH-cytochrome b5 reductase (diaphorase 1) gene

Hereditary methemoglobinemia due to reduced nicotin amide adenine dinucleotide (NADH)-cytochrome b5 reductase (b5r) deficiency is classified into an erythrocyte type (I) and a generalized type (II). We investigated the b5r gene of three unrelated patients with types I and II and found four novel mutations. The patient with type I was homozygous for a c.535 G-->A exchange in exon 6 (A179T). The patients with type II were found to be homozygous for a c.757 G-->A transition in exon 9 (V253M) and compound heterozygous for two mutations, respectively. One allele presented a c.379 A-->G transition (M127V). The second allele carried a sequence difference at the invariant 3' splice-acceptor dinucleotide of intron 4 (IVS4-2A-->G) resulting in skipping of exon 5. To characterize a possible effect of this mutation on RNA metabolism, poly(A)(+) RNA was analyzed by RT-PCR and sequencing. The results show that RNA is made from the allele harboring the 3'-splice site mutation. Furthermore, western blot analysis revealed a complete absence of immunologically detectable b5r in skin fibroblasts of this patient. The compound heterozygosity for the splice site and the missense mutations apparently caused hereditary methemoglobinemia type II in this patient. Hum Mutat 17:348, 2001.

[The iodine supply of newborns. Comparison of iodine absorption and iodine excretion of mother and child]

BACKGROUND

Since 1989 the use of iodized salt has been allowed in Germany, additional supplementation with iodide tablets has been recommended during pregnancy and lactation. This study was undertaken to clarify whether the iodine intake of neonates and young infants improved since then.

PATIENTS AND METHODS

In the first part of the study the urinary iodine excretion of 52 newborns and their mothers in 1998 was compared to data of similar studies 1983 in the area of Göttingen and 1982 in the areas of Heidelberg and Rothenburg, Germany. All these are geographically low-iodine areas. In the second part the iodine supply of infants in 1998-1999 under feeding with mother's milk or formulas in 1998 and 1999 was obtained by measuring iodide concentrations in urine and milk using a high pressure liquid chromatography (HPLC) method.

RESULTS

45% of pregnant women were without iodide supplementation in 1998. In 1998 the median urinary iodide concentration during the first week of life was 4.3 micrograms/dl, which was more than twice that found in 1983 (1.75 micrograms/dl). Infants feeding by mother's milk without maternal iodine supplementation or by semi-elementary diet had the lowest urinary iodine excretion, whereas significantly higher values were measured when feeding formulas for term or preterm infants.

CONCLUSIONS

The iodine intake of newborns has markedly improved during 15 years. The WHO criterias for adequate iodine supply (TSH < 5 microU/ml and urinary iodine >/ = 10 micrograms/dl) were only partly fulfilled in Göttingen indicating that a mild iodine deficiency still exists with the risk of iodine deficiency disorders.

GnRH antagonist cetrorelix prevents sexual maturation of peripubertal male rats

Gonadotropin releasing-hormone (GnRH) analogues contain amino acid substitutions of the native decapeptide. Depending on the substitutions, the analogues have GnRH agonistic or antagonistic properties. GnRH agonists are the established treatment in cases of central precocious puberty caused by premature activation of the hypothalamic GnRH pulse generator. Much less data exist on the use of GnRH antagonists to influence the onset of puberty. Using the GnRH antagonist cetrorelix we conducted a 5 day treatment of peripubertal male rats (cetrorelix group n=12, 100 microg/d intraperitoneally injected; placebo n=10, NaCl 0.9% intraperitoneally injected) from postnatal day 32 to 36 and decapitated on postnatal day 37 to investigate the effects on pubertal development, serum gonadotropin and testosterone levels as well as the GnRH release from explanted hypothalami. A control group of 5 male rats was added for hypothalamus superfusion experiments on day 25. We observed no progress of testicular development in the cetrorelix group. Cetrorelix injected rats had lower testicular weights (531+/-13 versus controls 819+/-25 mg, mean+/-SEM, p<0.0001). 12 h after the last injection testosterone levels were in the castrate range (serum testosterone, median controls: 1.7 ng/ml, median cetrorelix <0.30 ng/ml, p<0.001), and they showed lower serum LH and FSH compared to the same age placebo group. After decapitation the preoptic mediobasal hypothalamic area (POA/MBH) was dissected from 5 randomly selected rats from each treatment group and the release rates of GnRH were determined in superfusion experiments: The hypothalamic GnRH secretion was comparable in the CET and the same age placebo rats but significantly higher than in the 25 day old control group.

CONCLUSION

The GnRH antagonist cetrorelix inhibits the pituitary-gonadal axis in peripubertal male rats and may be effective in treating central precocious puberty in males.

Reduction of gamma-aminobutyric acid-ergic neurotransmission as a putative mechanism of radiation induced activation of the gonadotropin releasing-hormone-pulse generator leading to precocious puberty in female rats

Brain irradiation in prepubertal children with malignomas can cause precocious puberty. A selective cranial cobalt (Co(60))-irradiation technique has been developed in rats. In two experiments early juvenile (13-15 days old) female rats received a single dose of 5 Gy or sham irradiation. At pubertal age (post-natal days 33-34) irradiated rats had higher serum estradiol and luteinizing hormone levels. In experiment 1 irradiated rats had higher gonadotropin releasing-hormone (GnRH) mRNA levels in the preoptic area compared to controls (P<0.05). In experiment 2 the release rates of gamma-aminobutyric acid (GABA) in vitro from preoptic mediobasal hypothalamic areas of irradiated rats were significantly reduced after stimulation with the GABA(A) receptor agonist muscimol (maximum values 4607+/-804 vs. 7399+/-1048 pM in controls, mean+/-SEM, P<0.05). Radiation induced central precocious puberty might be caused by damage to inhibitory GABAergic neurons leading to premature activation of the GnRH-pulse generator.

Transient and controllable opening of the blood-brain barrier to cytostatic and antibiotic agents by alkylglycerols in rats

The blood-brain barrier hinders progress in the chemotherapy of brain tumors due to insufficient penetration of anticancer drugs into the brain tissue. Short-chain alkylglycerols affect the physicochemical properties of biological membranes. The enhancement of the blood-brain barrier permeability by intra-arterial administration of alkylglycerols was investigated in tumor-free and C6 astroglioma bearing rats. The antineoplastic agents cisplatin and methotrexate and the antibiotics vancomycin and gentamicin were selectively injected into the right internal carotid artery in the absence and presence of various alkylmono-, alkyldi-, and alkyltriglycerols. In normal rats the intra-arterial administration of the drugs without alkylglycerols resulted in low drug concentrations in brain tissue. In the presence of alkylglycerols (0.01-0.3 M) a reversible (within minutes) and concentration-dependent enrichment of the coinjected agents was found, preferentially in the ipsilateral hemisphere. The extent of drug accumulation in the brain was modified by changes in the chemical structure of the alkylglycerols. The effect increased with the chain length of the alkyl group, decreased with the number of glycerols, and varied from 2- to more than 230-fold compared to controls. In rats with C6 tumors 1-O-pentylglycerol increased the delivery of methotrexate 18-fold in the tumor, 28-fold in the surrounding brain, 18-fold in the contralateral brain, and 19-fold in the cerebellum compared to controls with methotrexate in the absence of pentylglycerol. In conclusion, the intra-arterial administration of alkylglycerols represents a novel and well controllable method for enhanced drug delivery to the brain and to brain tumors.

Primary myelosarcomas are associated with a high rate of relapse: report on 34 children from the acute myeloid leukaemia-Berlin-Frankfurt-Münster studies

Primary myelosarcomas are rare manifestations of acute myeloid leukaemia (AML) that precede bone marrow involvement. Out of 744 children observed during the AML-Berlin-Frankfurt-Münster (BFM) studies 87 and 93, 34 children presented with extramedullar myelosarcomas and no blasts (n = 21; 2.8%), or a low blast count (n = 13; 1.7%) in the bone marrow. Owing to the initially mild and variable symptoms, in some children (n = 12) diagnostic procedures were delayed and treatment intensity was reduced. At 0.65 +/- 0.13, the cumulative incidence of relapse was significantly higher than in other AML patients (0.28 +/- 0.02). The 5-year event-free survival was 0.19 +/- 0.08 (compared with 0.48 +/- 0.02 in AML-BFM studies 87/93; P(log rank) < 0.03). Overall, 18 out of 34 patients died from disease (estimated 5 year survival 0.44 +/- 0.09 compared with 0.55 +/- 0.02 in the AML-BFM-studies 87/93; P(log rank) = 0.35, n.s.). An early diagnostic workup is needed in children with unusual skin lesions or tumours, considering myelosarcoma as a primary manifestation of AML. Intensive AML-specific chemotherapy is recommended soon after diagnosis.

Eight novel mutations and consequences on mRNA and protein level in pyruvate kinase-deficient patients with nonspherocytic hemolytic anemia

Pyruvate kinase (PK) deficiency (PKD) is an autosomal recessive disorder with the typical manifestation of nonspherocytic hemolytic anemia. We analyzed the mutant enzymes of 10 unrelated patients with PKD, whose symptoms ranged from a mild, chronic hemolytic anemia to a severe anemia, by sequence analysis for the presence of alterations in the PKLR gene. In all cases the patients were shown to be compound heterozygous. Eight novel mutations were identified: 458T-->C (Ile153Thr), 656T-->C (Ile219Thr), 877G-->A (Asp293Asn), 991G-->A (Asp331Asn), 1055C-->A (Ala352Asp), 1483G-->A (Ala495Thr), 1649A-->T (Asp550Val), and 183-184ins16bp. This 16 bp duplication produces a frameshift and subsequent stop codon resulting in a drastically reduced mRNA level, and probably in an unstable gene product. Surprisingly, the existence of M2-type PK could be demonstrated in the patient's red blood cells. The study of different polymorphic sites revealed, with one exception, a strict linkage of the 1705C, 1738T, IVS5(+51)T, T(10) polymorphisms and the presence of 14 ATT repeats in intron 11. Our analyses show the consequences of a distorted structure on enzyme function and we discuss the correlations between the mutations identified and the parameters indicative for enzyme function.

Cranial irradiation of female rats causes dose-dependent and age-dependent activation or inhibition of pubertal development

Cranial irradiation in prepubertal children with leukemia or brain tumors can lead to precocious or in high doses to late puberty. To unravel the underlying mechanisms, we developed a rat model with selective cranial Co60-irradiation technique. Infantile (12-16 d old) or juvenile (21-23 d old) female Sprague-Dawley rats received a single dose of 4, 5, 6, 9 or 2 x 9 Gy (at days 21 and 23). Each group consisted of 7-20 animals. High radiation doses (9 Gy and more) caused retardation of sexual development, whereas low radiation doses (5 or 6 Gy) led to accelerated onset of puberty in 20% of infantile irradiated rats animals as determined by vaginal opening. Interestingly, at peripubertal age (postnatal day 32-34), 5 or 6 Gy infantile irradiated rats had significantly higher serum LH levels stimulated by GnRH and estradiol levels (p < 0.05). 2 x 9 Gy irradiated rats had at the age of 3 mo a marked growth retardation and significantly lower GH levels than the controls (p < 0.05) whereas prolactin, FSH, TSH, T4, and corticosterone levels were comparable with controls. These studies demonstrate that the GnRH-pulse generator is very radiosensitive as precocious activation occurred after low dose irradiation (5 or 6 Gy) of infantile rats without any other endocrine disorder. High radiation doses (9 or 2 x 9 Gy) induced retardation of sexual maturation and later on growth hormone deficiency. Moreover this model of cranial irradiation seems to be suitable to study the molecular mechanisms of radiation induced pubertal changes.

Rhabdoid tumors of the central nervous system

Rhabdoid tumors of the central nervous system are rare malignancies with a still almost uniformly fatal outcome. There is still no proven curative therapy available. We report our experience with nine patients with central nervous system rhabdoid tumors. Gross complete surgical removal of the tumor was achieved in six patients. Seven patients received intensive chemotherapy. Four of these were treated in addition with both neuroaxis radiotherapy and a local boost directed to the tumor region, while two patients received local radiotherapy only. The therapy was reasonably well tolerated in most cases. Despite the aggressive therapy, eight of the nine patients died from progressive tumor disease, and one patient died from hemorrhagic brain stem lesions of unknown etiology. The mean survival time was 10 months after diagnosis. Conventional treatment, although aggressive, cannot change the fatal prognosis of central nervous system rhabdoid tumors. As these neoplasms are so rare, a coordinated register would probably be a good idea, offering a means of learning more about the tumor's biology and possible strategies of treatment.

Glucose-6-phosphate isomerase deficiency

Most of the metabolic needs of erythrocytes are covered by glycolysis, the oxidative pentose phosphate pathway and the glutathione cycle. Hereditary enzyme deficiencies of all these pathways have been identified, among which glucose-6-phosphate isomerase (GPI) deficiency is the second most frequent erythroenzymopathy in glycolysis, being associated with non-spherocytic haemolytic anaemia of variable severity. This autosomal recessive genetic disorder may be associated in some cases with neurological impairment. GPI is a dimeric enzyme that catalyses the reversible interconversion of fructose-6-phosphate and glucose-6-phosphate. Virtually all the mutant gene products reported are characterized by marked instability and normal substrate affinities, but altered catalytic activity and electrophoretic migration rates. At the nucleotide level, 29 mutations have been reported. This chapter reviews (a) the clinical pattern of the condition; (b) biochemical and molecular studies; (c) structure-function relationships; (d) the molecular basis of neurological dysfunctions sometimes associated with GPI deficiency; and (e) the correlation between the severity of the anaemia and the molecular defect.

Features of Antley-Bixler syndrome in an infant born to a mother with pregnancy luteoma

We report a female newborn with characteristic signs of Antley-Bixler syndrome (ABS) such as midface hypoplasia, radiohumeral synostosis and multiple joint contractures. The newborn also presented ambiguous genitalia, stage Prader V, and congenital adrenal hyperplasia. The mother experienced midterm virilization due to a pregnancy luteoma. Her elevated androgen levels and virilization symptoms normalized post partum without treatment. The newborn had elevated serum testosterone and 17-OH-progesterone levels which remained elevated because of a 21-hydroxylase deficiency. The child's treatment in order of priority was: hydrocortisone substitution, craniofacial/skeletal anomaly management and surgical correction of the external genitalia. Mutations in the genes for fibroblast growth factor (FGF) 8 and receptors FGFR1, FGFR2, and FGFR3 were not detected.

CONCLUSION

A newborn girl with manifestations of the Antley-Bixler syndrome showed severe virilization probably caused by the association of a mild 21-hydroxylase deficiency and maternal hyperandrogenism due to a pregnancy luteoma. Abnormalities of androgen metabolism may be responsible for virilization reported in other cases of the Antley-Bixler syndrome.

Erucylphosphocholine: pharmacokinetics, biodistribution and CNS-accumulation in the rat after intravenous administration

The clinical use of alkylphosphocholines (APC) in cancer patients is restricted because of the high gastrointestinal toxicity and the need for oral administration. Therefore we evaluated the clinical pharmacology of erucylphosphocholine (ErPC), the first derivative of the APC family suitable for intravenous administration with strong antineoplastic activity, in vitro and in vivo in rats. The pharmacokinetic parameters after a single intravenous dose of 40 mg/kg were calculated using a two-compartment model: C(max) = 1.6 +/- 0.3 micromol/ml, T(1/2alpha) = 0.18 +/- 0.09 h, T(1/2beta) = 3.3 +/- 0.88 h, clearance = 9.7 +/- 1.2 ml/h, AUC = 2.5 +/- 0.3 micromol/ml per h and Vss = 40.4 +/- 7.9 ml. Biodistribution studies were performed after repeated ErPC administration at different doses. Intravenous injections of 20 mg/kg given at intervals of 48 h for up to 4 weeks were well tolerated. Neither clinical evaluation nor laboratory parameters (haematology and clinical chemistry) revealed toxic side effects. In contrast, higher doses of ErPC (40 mg/kg per 48 h) led to weight loss. After 2 and 4 weeks of therapy with 20 mg/kg per 48 h a high ErPC accumulation was found in the adrenal glands, small intestine and brain. The brain to serum concentration ratios averaged 2.1 after 2 weeks and 4.5 after 4 weeks. Significant leucocytosis and thrombocytosis were observed after 4 weeks of ErPC treatment. The findings suggest that ErPC is a suitable candidate for clinical trials. In particular, owing to the high accumulation in brain tissue, ErPC is a potential agent for chemotherapy against malignant brain tumours.

Application of RHD and RHCE genotyping for correct blood group determination in chronically transfused patients

BACKGROUND

In chronically transfused patients, conventional blood group typing may be impossible because of mixed-field agglutination.

STUDY DESIGN AND METHODS

In 27 patients with congenital anemia and lifelong transfusion history, genotyping for D, RHD, and RHCE was performed with polymerase chain reactions. These results were compared with the blood group typing results documented in the medical record.

RESULTS

Two of 27 cases had been typed D-negative by serologic tests and D-positive by genotyping. In 20 patients, the CDE formula had been determined serologically according to the medical record; 4 of these patients were Cc by serologic tests and C/C by genotyping. One patient typed ee by serologic tests, and genotyping revealed heterozygosity (E/e).

CONCLUSION

In patients with a lifelong transfusion history, serologic blood group determination may be impossible, and pretransfusion test results are not always available or reliable. In whites, Rh-matched transfusions are possible with genotyping. The genetic background of the RH genes has to be elucidated in other ethnic groups, such as in black patients with sickle cell disease, before genotyping can be applied without restriction.

[Primary isolated myeolosarcoma in childhood]

Isolated myelosarcomas are rare first manifestations of acute myeloid leukemia (AML), preceding bone marrow involvement by weeks to months. Seventeen of 654 children observed during the studies AML-BFM 87 and 93 were diagnosed as extramedullar myelosarcomas (2.6%). The predominantly myelomonocytic or monoblastic tumor cells (M4 or M5 according to FAB classification) mainly infiltrated skin (n = 8). Additional tumors were located in mucosa (n = 2), central nervous system (n = 2), orbita (n = 2), bone (n = 1), glandulae parotis (n = 1) and lymph nodes. Due to the initial mild and variable symptoms in some children the diagnostic measurements were delayed and treatment was inadequate. This might be responsible for the high rate of relapse (79%) and the poor outcome. Ten of 17 patients died from disease (estimated survival 0.27 +/- 0.13 compared to AML-BFM 87/93 0.51 +/- 0.03). Suspect skin lesions or tumors should be considered as isolated myelosarcoma of a primary manifestation of AML. An intensive AML-specific chemotherapy is recommended.

[Antiinfectious prophylaxis in pediatric oncology. Work group "Quality Assurance" of Society for Pediatric Oncology and Hematology (GPOH)]

Infections in disease- and/or chemotherapy-related neutropenia are major, often emergency-type problems in the treatment of pediatric oncology patients and explain the ongoing discussion about antiinfectious prophylaxis. The different aspects of prophylaxis and an overview on the literature are presented. Antiinfectious prophylaxis in pediatric oncology includes the following issues: 1. General aspects such as information for patients and parents on neutropenia and risk of infectious diseases and indication and management of reverse isolation and barrier isolation; 2. antibacterial prophylaxis with oral non-absorbable and oral absorbable antibiotics; 3. Pneumocystis carinii (Pc) prophylaxis; 4. antifungal prophylaxis to prevent disseminated candidiasis and aspergillosis; 5. antiviral prophylaxis, especially varicella-zoster-virus (VZV) post-exposure prophylaxis and cytomegalovirus (CMV) prophylaxis; 6. immunoglobulins and hematopoietic growth-factors (HGF); 7. active immunization. An evaluation of those measures leads to the following conclusions: A major controversy exists regarding antibacterial and antifungal prophylaxis. Probably not effective are the use of reverse isolation and of oral, non-absorbable antibiotics. Oral absorbable antibiotics, antifungal prophylaxis using fluconazole and amphotericin B and the use of hematopoietic growth factors are likely to be effective. Clearly effective are strict hand-washing procedures, Pc and CMV prophylaxis and passive vaccination against VZV in case of VZV exposure of a seronegative patient.

Identification of a novel promoter mutation in the human pyruvate kinase (PK) LR gene of a patient with severe haemolytic anaemia

Using direct sequencing we analysed the pyruvate kinase (PK) LR gene of a patient with severe haemolytic anaemia due to PK deficiency. A novel promoter mutation -249delA relative to the translation initiation site and the common 1529A mutation in exon 11 of the gene could be identified. Reverse transcription (RT)-PCR analysis combined with restriction digestion revealed that the -249delA mutation leads to a reduction in the amount of mRNA produced from this allele to about 6% of normal. We assume that both mutations would account for the PK deficiency in the compound heterozygous patient.

Erucylphosphocholine, a novel antineoplastic ether lipid, blocks growth and induces apoptosis in brain tumor cell lines in vitro

A potential benefit of alkylphosphocholines in brain tumor therapy was evaluated. The in vitro effects of the intravenously applicable erucylphosphocholine (ErPC) on proliferation, viability, morphology and cell cycle distribution of a rat glioma, four human astrocytoma/glioblastoma and a human medulloblastoma cell line were analyzed daily after continuous drug-exposure for up to six days. ErPC exerted strong cytostatic and direct cytotoxic effects on all cell lines tested at drug concentrations that are achieved in the rat brain after repeated intravenous injections of nontoxic drug doses. Concentrations of 70 microM (T98G, A172, 85HG66, 86HG39) and 110 microM (C6, D283 Med) led to complete cell death within 48-96 h. Particular characteristics of ErPC action are i) the accumulation of cells with a 4n DNA content corresponding to the G2/M-phase of the cell cycle, ii) the formation of two- and multinucleated cells and iii) the induction of apoptosis.

Molecular basis of neurological dysfunction coupled with haemolytic anaemia in human glucose-6-phosphate isomerase (GPI) deficiency

Glucose-6-phosphate isomerase (GPI) deficiency, an autosomal recessive genetic disorder with the typical manifestation of nonspherocytic haemolytic anaemia, can be associated in some cases with neurological impairment. GPI has been found to be identical to neuroleukin (NLK), which has neurotrophic and lymphokine properties. To focus on the possible effects of GPI mutations on the central nervous system through an effect on neuroleukin activity, we analysed DNA isolated from two patients with severe GPI deficiency, one of them with additional neurological deficits, and their families. The neurologically affected patient (GPI Homburg) is compound heterozygous for a 59 A-->C (H20P) and a 1016 T-->C (L339P) exchange. Owing to the insertion of proline, the H20P and L339P mutations are likely to affect the folding and activity of the enzyme. In the second family studied, the two affected siblings showed no neurological symptoms. The identified mutations are 1166 A-->G (H389R) and 1549 C-->G (L517V), which are located at the subunit interface. We propose that mutations that lead to incorrect folding destroy both catalytic (GPI) and neurotrophic (NLK) activities, thereby leading to the observed clinical symptoms (GPI Homburg). Those alterations at the active site, however, that allow correct folding retain the neurotrophic properties of the molecule (GPI Calden).

Ontogeny of the GNRH-, glutaminase- and glutamate decarboxylase-gene expression in the hypothalamus of female rats

Amino acid neurotransmitters like gamma-aminobutyric acid (GABA) and glutamate (GLU) are involved in the regulation of hypothalamic gonadotropin releasing hormone (GnRH) release. We investigated, whether there are changes of gene expression in the rat hypothalamus for GnRH, GnRH receptor, as well as glutaminase and glutamate decarboxylase, two enzymes regulating neurotransmitter concentrations of GLU and GABA in the brain during the ontogeny. After reverse transcription-polymerase chain reaction (RT-PCR) we used an ELISA method to quantify PCR products. In 15-day old animals high plasma luteinizing hormone (LH) levels with pronounced variations were found. In 25-day old animals LH values were low, whereas in 35-day old rats LH levels increased significantly indicating the reactivation of the GnRH-pulse generator at the beginning of puberty. In parallel to these changes, the mRNA levels of the GnRH receptor in the mediobasal hypothalamus were high at day 15, significantly lower at day 25 and again high at day 35 after birth (ELISA O.D. GnRH-R day 15: 0.46+/-0.07, day 25: 0.16+/-0.04, day 35: 0.36+/-0.04; p<0.01), but no changes of GnRH receptor gene expression were found in the preoptic area. The mRNA of GnRH in the preoptic area as well as mRNA levels of glutaminase and glutamate decarboxylase in the mediobasal hypothalamus and the preoptic area did not change during ontogeny. We conclude that hypothalamic GnRH receptors are involved in the characteristic changes of LH secretion patterns during sexual maturation. Major changes of GnRH receptor gene expression occurred in the mediobasal hypothalamus and correlated well with plasma LH levels, whereas hypothalamic mRNA levels of GnRH, glutaminase and glutamate decarboxylase did not change within the different age groups. Thus the activity of the GABA- and glutamatergic system during ontogeny may be regulated at the receptor or postreceptor level.

Antitumor effects of erucylphosphocholine on brain tumor cells in vitro and in vivo

The antineoplastic activity of erucylphosphocholine (ErPC) on C6 rat glioma cells and the human glioblastoma cell lines A172 and T98G was studied in vitro. ErPC exerted concentration- and time-dependent cytostatic and cytotoxic actions. The effects of ErPC on C6 cells were stronger than hexadecylphosphocholine and similar to 1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine. The human cell lines were more sensitive to ErPC (LC50 = 36 microM and 29 microM) than C6 cells (LC50 = 70 microM) (48 hours, WST-1-test). Morphological characteristics of apoptotic cell death were observed. Rats bearing intracerebral and subcutaneous gliomas were treated with intravenous ErPC for 30 days to determine the antitumor effects of ErPC in vivo. ErPC accumulation in subcutaneous tumors was higher than in brain tissue. Peripheral tumors revealed a better response than CNS-tumors. There was a strong negative relationship between the concentration of ErPC and the weight of peripheral tumors. ErPC is considered to be promising for chemotherapy of malignant brain tumors.

Autoimmune thyreoiditis in childhood--epidemiology, clinical and laboratory findings in 61 patients

Autoimmune thyroiditis (AT) is the most common cause of nonendemic goiter and acquired hypothyroidism in children and adolescents. In 61 patients AT was diagnosed following clinical, ultrasonographic, biochemical and cytological examinations. Girls were more often affected than boys, the female/male ratio in our patients was 9:1. Clinically the vast majority of patients had a goiter. Approximately half of the patients were euthyroid (n = 29). In the other patients hyperthyrotropinaemia (n = 16), hypothyroidism (n = 9) and hyperthyroidism (n = 7) were evident. Thyroid microsomal and peroxidase antibodies were elevated in most of the patients, while thyroglobin antibodies were less frequently elevated. As AT without detectable thyroid antibodies can occur, a fine-needle aspiration cytology of the thyroid is important in nontypical cases. This type of cytologic examination should also be considered in patients with euthyroid nonendemic goiter, thyroid nodules and hyperthyroid goiter.

Short stature and failure of pubertal development in thalassaemia major: evidence for hypothalamic neurosecretory dysfunction of growth hormone secretion and defective pituitary gonadotropin secretion

In patients with beta-thalassaemia major, frequent blood transfusions combined with desferrioxamine chelation therapy lead to an improved rate of survival. Endocrine disorders related to secondary haemosiderosis such as short stature, delayed puberty and hypogonadism are major problems in both adolescent and adult patients. A total of 32 patients with beta-thalassaemia major undergoing treatment at the Children's Hospital, University of Göttingen were examined. Fourteen of these were short in stature. Growth hormone (GH) secretion was investigated in 13 patients exhibiting either a short stature or reduced growth rate. The stimulated GH secretion of 10 patients in this subgroup lay within the normal range. Studies of their spontaneous GH secretion during the night revealed that these patients had a markedly reduced mean GH and reduced amplitudes in their GH peaks. Low insulin-like growth factor (IGF)-I levels were seen in the growth-retarded thalassaemic patients. Eight were subjected to an IGF generation test and showed a strong increase in both IGF-I and insulin-like growth factor binding protein (IGFBP)-3 levels indicating intact IGF-I generation by the liver. Hypogonadotropic hypogonadism was found to be present in both the male and female patients with impaired sexual development. After priming with LH-releasing hormone (GnRH) per pump in 2 female and 5 male patients, no change in either their serum oestradiol or testosterone levels or in LH/FSH response to GnRH was observed suggesting that they were suffering from a severe pituitary gonadotropin insufficiency. Three male patients at the age of puberty but exhibiting short stature. low GH, low IGF-I and hypogonadism received low dose long-acting testosterone. After 3 12 months of therapy there was a marked growth spurt, higher nocturnal GH levels and an increase in both IGF-I and IGFBP-3.

CONCLUSION

Reduced GH secretion and low IGF-I in thalassaemic patients are related to a neurosecretory dysfunction due to iron overload rather than to liver damage. Hypogonadotropic hypogonadism is caused by the selective loss of pituitary gonadotropin function. In patients with both GH deficiency and hypogonadism, low dose sexual steroid treatment should be considered either as an alternative or an additional treatment before starting GH therapy.

Glucose phosphate isomerase deficiency: biochemical and molecular genetic studies on the enzyme variants of two patients with severe haemolytic anaemia

Biochemical and molecular genetic studies were performed on the enzyme variants of two patients compound heterozygous for glucose phosphate isomerase (GPI) deficiency, both suffering from severe haemolytic anaemia. The enzymes of case 1 (GPI 'Zwickau') and case 2 (GPI 'Nordhorn' [25]), revealed reduced GPI activity and remarkable thermolability. Glucose-6-phosphate (Gluc-6-P) concentration was elevated 2.3 times in case 1 and 3.8 times in case 2. Sequencing the patients' GPI genes showed four different point mutations, two of them involving highly conserved amino acids. The c1039 C-->T substitution, found in the gene of GPI 'Zwickau', has been described recently [30] and causes an Arg 347-->Cys substitution close to the putative catalytic site. The second mutation in this case is a novel c1538 G-->A substitution causing a Trp-->stop mutation at position 513 apparently resulting in premature RNA degradation thus resulting either in a complete lack of protein or a protein which does not show GPI activity. In the gene of GPI 'Nordhorn' a c1028 A-->G mutation was discovered, also previously described [1, 9] causing a Gln 343-->Trp substitution. The second mutation was a novel splice site mutation at the border of intron 15 to exon 16: IVS15-(-2) A-->C which leads to an aberrant splicing of exon 16, thus resulting either in a truncated and most likely inactive enzyme or in no protein at all.

CONCLUSION

Biochemical and molecular genetic studies performed with the enzyme variants GPI 'Zwickau' and GPI 'Nordhorn' showed that in both cases the simultaneous occurrence of a single amino acid substitution affecting the active site, together with a nonsense mutation leading to the loss of major parts of the enzyme probably explains the severe clinical course of the disease.

Erythrocyte pyruvate kinase- and glucose phosphate isomerase deficiency: perturbation of glycolysis by structural defects and functional alterations of defective enzymes and its relation to the clinical severity of chronic hemolytic anemia

The pathogenesis of two metabolic disorders caused by enzyme defects in the red blood cell leading to hemolytic anemia, and in some cases of glucose phosphate isomerase (GPI) deficiency additionally to neurological impairment was investigated. Rheological studies were performed to determine the influence of a shortage of energy on the deformability of the erythrocytes. The functions of the enzymes were determined by studying the enzyme kinetics, the temperature dependence of the enzyme activity and the migration of the proteins in an electric field. A detailed molecular genetic analysis of the gene encoding for the given protein allowed the detection of mutations involving amino acid exchanges which cause alterations of the protein structure. For both enzyme deficiencies, a good correlation was found between the structural changes (usually caused by single point mutations in the gene), the altered function of the enzymes and the severity of the clinical picture. The exchange of amino acids close to either the active site or the regulatory domain results in a decreased turnover as well as an alteration of the regulatory properties of the enzymes; this usually leads to an increased severity of the disease. Increased concentrations of glucose-6-phosphate (G-6-P), found in all red blood cells of patients suffering from hemolytic anemia caused by pyruvate kinase (PK) and GPI deficiency, correlate well with the severity of the clinical picture, apparently reflecting the degree of the perturbation of glycolysis. This results in a lack of the energy donor adenosine triphosphate (ATP); this leads then to a destabilization of the red cell membrane which causes earlier lysis of the red blood cell, which in turn gives rise to hemolytic anemia of variable degrees. One patient with neurological symptoms has been studied so far biochemically and at the molecular genetic level. The point mutations found in this patient's GPI gene support the idea that GPI may have a neurological function in addition to its role in the carbohydrate metabolism; this is due to the presence of a monomeric sequence analogue called neuroleukin (NLK). The mutations apparently lead to the incorrect folding of this neurotrophic factor, and thus destroy the neurological activity.

[Neonatal Basedow's disease in twins from a mother with severe T3 hyperthyroidism]

HISTORY AND CLINICAL FINDINGS

Dizygotic twin sisters were born to a woman who, shortly before becoming pregnant, had developed Graves' disease with markedly elevated triiodothyronine (T3) levels and highly positive TSH receptor antibody titres (TRAb: 169 mU/ml). From the second week of life onwards they had a goitre and hyperexcitability, tachycardia and failure to thrive were noted. In addition, twin I had mild exophthalmos. As thyrostatic treatment of the mother was very difficult, intrauterine hypothyroidism or transitory hyperthyroidism had presumably occurred in the twins.

INVESTIGATIONS

Twin I had maximal thyroxine (T4) concentration of 26.2 micrograms/dl, while it was 24.7 micrograms/dl in twin II with suppressed TSH. Both twins had high concentrations of TRAb and antibodies against thyroid peroxidase.

DIAGNOSIS, TREATMENT AND COURSE

With the diagnosis of neonatal Graves' disease established, both twins were treated with propranolol (2 mg/kg.d) and phenobarbitone (2-4 mg/kg.d). Twin I, whose symptoms were more severe, also received propylthiouracil (5 mg/kg.d) until euthyroidism had been achieved. Although twin II became euthyroid spontaneously, she gained weight only slowly and microcephaly developed together with definite motor and mental retardation. It remains unclear whether these were consequences of intrauterine hypothyroidism or post-partum hyperthyroidism.

CONCLUSION

Graves' disease during pregnancy demands interdisciplinary collaboration between gynaecologist, physician and paediatrician to prevent severe sequelae in the children. Early risk assessment is possible by measuring the TSH receptor antibody titre in umbilical blood.

[Diagnosis of pyruvate kinase deficiency in the presence of an elevated reticulocyte count]

HISTORY AND CLINICAL FINDINGS

Three members of one family (mother, now aged 44 years; daughter, now aged 23 years, and son, now aged 19 years) have had chronic haemolytic anaemia since their infancy. All three have had several blood transfusions a year because of haemoglobin (Hb) concentrations as low as 5 g/dl due to intermittent increases in haemolysis. Despite an unclear diagnosis all three had splenectomies: their spleens had been enlarged to about 5-7 cm below the rib margin. After splenectomy their haemoglobin concentration rose to 9-12 g/dl and the previously raised reticulocyte count of 150-250/1000 rose further to 400-700/1000. None of the patients had symptoms other than a slight decrease in exercise tolerance. They were admitted to hospital for further evaluation. Physical examination was unremarkable except for slight jaundice and well healed splenectomy scar.

TESTS

All three patients had normochromic haemolytic anaemia (Hb 10-12 g/dl), bilirubin 2-3 mg/dl, lactate dehydrogenase activity 400-600 U/l). The reticulocyte count was raised to 420-690/1000. In all of them pyruvate kinase (PK) activity was normal or slightly increased if related to Hb concentration. Reticulocytes from healthy persons were isolated by density-gradient centrifugation so that samples could be prepared with different numbers of reticulocytes: PK activity was found to be dependent on the sample's reticulocyte count. In the three patients PK deficiency could, therefore, only be diagnosed by taking into account the raised reticulocyte count.

CONCLUSION

As reticulocytes have a higher PK activity than erythrocytes the reticulocyte count must be taken into account when assessing the significance of a given value of this enzyme's activity.

Staging problems in the pre-operative chemotherapy of Wilms' tumour

OBJECTIVE

To determine the effect of the International Society of Paediatric Oncology (SIOP) Wilms' tumour protocols (pre-operative chemotherapy based on clinical and radiological findings, with no prior tumour verification by open or needle biopsy) on subsequent intra-operative tumour diagnosis and staging.

PATIENTS AND METHODS

The diagnosis and staging of possible Wilms' tumour by clinical, ultrasonographic and radiological assessment were compared with the intra-operative findings in 14 consecutive children (1-12 years of age) treated between 1989 and 1994.

RESULTS

A diagnosis of Wilms' tumour was histologically verified in 11 of 14 children. In two children, verification was not possible due to complete necrosis of the tumour following pre-operative chemotherapy. In a 12-year-old boy with an estimated stage IV disease due to a solitary lung metastasis, a renal cell carcinoma was revealed in the nephrectomy specimen while subsequent thoracotomy revealed dysmorphic but not malignant tissue. The estimated tumour stage was correct with regard to localized or metastatic disease in nine of 11 children with histologically confirmed Wilms' tumour, while in two children with an estimated stage II tumour, liver metastases were found intra-operatively and the tumour was upstaged to IV.

CONCLUSION

Exact tumour diagnosis and staging was difficult in these patients. Although the accuracy of tumour staging depends on the sensitivity of radiological and ultrasonographic examinations, difficulties in tumour diagnosis may be overcome by biopsies of the primary tumour. The justification of upstaging a low-stage I/II tumour to stage III, provoking a more intense post-operative treatment, should be proven by prospective randomized studies. The decision to perform a primary tumour biopsy would be facilitated if possible subsequent deterioration of outcome could be excluded.

Triosephosphate isomerase deficiency: biochemical and molecular genetic analysis for prenatal diagnosis

Inherited deficiency of the glycolytic enzyme triosephosphate isomerase leads to a multisystem disorder characterized by progressive neuromuscular dysfunction, chronic nonspherocytic hemolytic anemia and increased susceptibility to severe infections. Most patients die within the first 6 years. We examined a family with severe triosephosphate isomerase deficiency. The 1-year-old index patient suffered from hemolytic anemia, neuromuscular impairment and pneumonias, with the necessity of intermitten mechanical ventilation. Triosephosphate isomerase activity in erythrocytes was reduced to about 20% of normal. Heat stability of the enzyme was strongly reduced; concentration of the physiological substrate, dihydroxyacetone phosphate was increased 20-fold due to the metabolic block. Direct sequencing of the triosephosphate isomerase gene revealed homozygosity for the formerly described GAG-->GAC-mutation changing 104 Glu-->Asp. During a 2nd pregnancy we examined a cord blood sample obtained in the 19th gestational week. The biochemical data on enzyme activity, heat stability of the enzyme and concentration of dihydroxyacetone phosphate were in the normal range. The molecular genetic analysis confirmed the presence of the normal triosephosphate isomerase alleles. Pregnancy was continued, resulting in the delivery of an unaffected, healthy newborn.

Mutations in the R-type pyruvate kinase gene and altered enzyme kinetic properties in patients with hemolytic anemia due to pyruvate kinase deficiency

The biochemical properties of erythrocyte pyruvate kinase (PK) together with mutations found in the coding sequence of the R-PK gene in five patients with severe hemolytic anemia due to PK deficiency are described. The enzyme variants were designated PK 'Mosul' (homozygote), PK 'Bukarest', PK 'Hamburg', PK 'Köln', and PK 'Essen' (compound heterozygote). PK 'Mosul' showed normal positive cooperative substrate binding, PK 'Bukarest' exhibited non-cooperative behavior, and PK 'Hamburg' and PK 'Köln' displayed mixed cooperativity, whereas PK 'Essen' was negative cooperative. PK 'Mosul' was found to be homozygous for the mutation 1151 ACG to ATG, resulting in an amino acid substitution 384 Thr to Met. In one allele of PK 'Bukarest' a single nucleotide substitution GAG-TAG was found at nucleotide 721, causing a change of 241 Glu to a chain termination codon (PK 'Bukarest'). Additionally, in the second allele of this patient a point mutation at position 1594 (CGG-TGG) occurs, changing 532 Arg to Trp (PK 'Bukarest'). Direct sequencing showed the heterozygosity of the patient's mother (PK 'Bukarest'/normal) at position 721 and of the patient's father (PK 'Bukarest'/normal) at position 1594. A point mutation at position 1529 (CGA-CAA), causing an amino acid substitution 510 Arg-Gln, was identified in PK 'Hamburg' and PK 'Köln'. The second mutation in these variants was not detected. In PK 'Essen' no mutation in the coding sequence was found at all. Screening for the mutation at position 1529 in further compound heterozygote patients and in normal subjects of Western European origin showed that this exchange is a common mutation responsible for PK deficiency in this population.

[Lysis of cytostatic drug-associated axillary vein thrombosis]

A 3 years old patient receiving chemotherapy for acute-lymphoblastic leukemia according to the ALL-BFM 90-treatment protocol developed thrombosis of the vena axillaris. Without removing the central venous catheter located at the site of thrombosis it was possible to lyse the thrombus by the systemic application of recombinant human tissue-type plasminogen activator (rt-PA). The method is recommended for the treatment of thrombotic occlusions in children.

[Nephroblastomatosis: a precancerous condition of Wilms' tumor]

Nephroblastomatosis is a precursor of Wilms' tumor. In this paper we report on a child with bilateral nephroblastomatosis. Although ultrasound and computed tomography showed extensive lesions, especially in the left kidney, no Wilms' tumor tissue was found histologically. Both kidneys regressed to normal size after chemotherapy.