Comparison of clinical and laboratory characteristics during two major paediatric meningitis outbreaks of echovirus 30 and other non-polio enteroviruses in Germany in 2008 and 2013.

Viral meningitis is mainly caused by non-polio enteroviruses (NPEV). Large-scale data on the clinical characteristics between different outbreaks within the same region are lacking. This study aimed to analyse a possible influence of the circulating NPEV genotype on the disease outcome of affected children. A retrospective cohort study analysing two major outbreaks of NPEV meningitis in Germany in 2008 and 2013 was conducted in cooperation with the National Reference Centre for Poliomyelitis and Enteroviruses (NRC PE) and five German children's hospitals. A total of 196 patients with laboratory-confirmed NPEV meningitis were enrolled. In 2008, children with NPEV meningitis had significantly higher fever and showed more behavioural changes and less back pain. To better define typical findings in echovirus 30 (E-30) meningitis, patients were split into the following three groups: E-30 positive patients, patients with "Non E-30" infection and patients with "Untyped" NPEV infection. E-30 positive patients were significantly older and their disease course was more acute, with early admission to but also early discharge from hospital. E-30 positive patients showed a significantly higher rate of headache and meningism, and a lower rate of diarrhoea and clinically defined septicaemia when compared to the others. Regarding laboratory testing, E-30 positive patients presented with significantly elevated peripheral blood neutrophil counts when compared to patients with "Non E-30" or "Untyped" NPEV infection. In conclusion, E-30 meningitis in children shows a characteristic pattern of clinical features. To further characterise NPEV strains worldwide, continuous surveillance and typing of NPEV strains causing central nervous system disease is warranted.

[Ornithine transcarbamylase deficiency in adolescence and adulthood: first manifestation with life-threatening decompensation]. / Ornithintranscarbamylasemangel im Jugend- und Erwachsenenalter: Erstmanifestation mit lebensbedrohlicher Dekompensation.

BACKGROUND: Ornithine transcarbamylase (OTC) deficiency is the most frequent innate disorder of the urea cycle and is X-chromosome linked. The disease normally manifests itself shortly after birth and is fatal when untreated. Due to the different expression and X-chromosomal inheritance the manifestation of symptoms can appear later particularly in girls and young women. The first symptoms are non-specific signs of elevated cerebral pressure as a result of a hyperammonemia, which range from nausea and headache up to cerebral herniation with fatal outcome. Measurement of plasma ammonia levels is a simple yet important screening test for patients with unexpected stupor or delirium. CASE REPORTS: The two case reports show the clinical range from acute decompensation with acute cerebral herniation followed by fatal outcome to recovery under emergency therapy without substantial neurological deficits. THERAPY: Emergency treatment consists of symptomatic securing of vital parameters and an immediate reduction in the ammonia level using high calorie, protein-free nutrition to avoid catabolism together with administration of arginine, benzoate or phenyl butyrate. In cases of coma with severe cerebral edema and the threat of a herniation reaction or excessive ammonia levels, emergency hemodialysis must be immediately carried out. CONCLUSIONS: In the clinical routine it is extremely important to consider a metabolic defect at an early phase and among others to determine the ammonia level so that the appropriate treatment can be instigated in time.

Hypoxic-ischemic encephalopathy with cystic brain stem necroses and thalamic calcifications in a preterm twin.

A severe and rare ischemic brain lesion in a preterm twin boy is reported. The boy was born after two weeks of anhydramnios and amnionic infection at 24 weeks of gestation. Following a difficult Caesarean section and prolonged umbilical cord compression he developed prenatal acidosis with an umbilical cord pH of 6.96. At the age of 7 h, heart rate variability narrowed due to severely disturbed brain stem function and the patient developed clinical signs of hypoxic-ischemic encephalopathy. Sonography demonstrated extensive symmetrical brain stem and basal ganglia lesions. After a prolonged comatose and apneic state, death occurred at the age of 25 days. Autopsy confirmed columnar bilateral cavitation of basal ganglia, diencephalon, brain stem and spinal gray matter, as well as focal calcifications in the palladium, thalamus, and brain stem. The findings highly resemble those observed after experimental or clinical cardiac arrest.

Nitroglycerin application during cesarean delivery: plasma levels, fetal/maternal ratio of nitroglycerin, and effects in newborns.

OBJECTIVE: We sought to investigate maternal and fetal nitroglycerin metabolization and to assess the clinical condition of neonates after intravenous nitroglycerin application during cesarean delivery. STUDY DESIGN: At the time of the uterine puncture incision, either 0. 25 mg or 0.5 mg nitroglycerin or a physiologic sodium chloride solution was administered as an intravenous bolus. Plasma concentrations of nitroglycerin and its metabolites were measured in maternal venous blood and in umbilical blood samples taken immediately after cord clamping. Arterial blood pressure, pulse rates, and Apgar scores were recorded for the neonates 1, 5, and 10 minutes after birth. RESULTS: Sixty-two patients were included in the pharmacokinetic study. Median maternal plasma levels 1 and 5 minutes after injection of 0.5 mg nitroglycerin were 80 and 3.2 ng/mL, respectively; median maternal plasma levels 1 and 5 minutes after injection of 0.25 mg nitroglycerin were 38 and 1.2 ng/mL, respectively. In the umbilical vein 1 minute after application of 0. 5 mg or 0.25 mg nitroglycerin, the plasma levels were 0.41 and 0.09 ng/mL, respectively, and in the umbilical artery they were 0.03 and 0.008 ng/mL, respectively. Circulatory parameters and Apgar scores in the neonates did not differ significantly from those found in the placebo group. CONCLUSION: The level of nitroglycerin in umbilical plasma was two to three orders of magnitude lower than that found in maternal plasma and clearly in a subtherapeutic range. There was no indication that prenatal application of nitroglycerin to facilitate obstetric management is hazardous for neonates.

Changing practices of red blood cell transfusions in infants with birth weights less than 1000 g.

OBJECTIVE: Extremely low birth weight (ELBW) infants frequently undergo transfusion because they are critically ill, often need artificial ventilation, and have the highest blood sampling loss in relation to their weight. During the last decade our transfusion guidelines were changed 3 times to become more restrictive. We hypothesized that these modifications substantially decreased the number of transfusions in our ELBW infants. METHODS: We performed a single-center analysis of 256 infants with birth weights from 500 to 999 g who were admitted from 1989 to 1997 and included 3 study periods, each starting with newly modified transfusion guidelines in April 1989, September 1991, and January 1995. We evaluated prospectively recorded clinical data and retrospective chart analysis for transfusion-related information. RESULTS: The median number of transfusions per infant decreased from 7 in the first period to 2 in the third period, whereas donor exposure decreased from 5 to 1 and blood volume transfused decreased from 131 to 37 mL/kg birth weight (P <.01). The median venous hematocrit measured before transfusion decreased from 43% to 35% in infants who underwent ventilation and from 41% to 31% in spontaneously breathing infants. The median birth weight decreased from 870 to 740 g and the median gestational age from 27 to 25 completed weeks (P <.01). The overall survival rate was 75% and did not change. The incidences of retinopathy, intraventricular hemorrhage, and patent ductus arteriosus remained unchanged. CONCLUSION: Over this 9-year period with increasingly restrictive transfusion guidelines, the transfusion number decreased by 71% and the donor exposure by 80% in ELBW infants without adverse clinical effects.

A point mutation Thr(799)Met on the alpha(2) integrin leads to the formation of new human platelet alloantigen Sit(a) and affects collagen-induced aggregation.

A new platelet-specific alloantigen, termed Sit(a), was identified in a severe case of neonatal alloimmune thrombocytopenia. The Sit(a) alloantigen is of low frequency (1/400) in the German population. Immunochemical studies demonstrated that the Sit(a) epitopes reside on platelet glycoprotein (GP) Ia. Nucleotide sequence analysis of GPIa cDNA derived from Sit(a)-positive platelets showed C(2531)-->T(2531) point mutation, resulting in Thr(799)Met dimorphism. Analysis of genomic DNA from 22 Sit(a)-negative normal individuals showed that the Thr(799) is encoded by ACG(2532) (90.9%) or ACA(2532) (9.1%). To establish a DNA typing technique, we elucidated the organization of the GPIa gene adjacent to the polymorphic bases. The introns (421 bp and 1.2 kb) encompass a 142-bp exon with the 2 polymorphic bases 2531 and 2532. Polymerase chain reaction-restriction fragment length polymorphism analysis on DNA derived from 100 donors using the restriction enzyme Mae III showed that the Met(799) form of GPIa is restricted to Sit(a) (+) phenotype. Analysis of stable Chinese hamster ovary transfectants expressing allele-specific recombinant forms of GPIa showed that anti-Sit(a) exclusively reacted with the Glu(505)Met(799), but not with the Glu(505)Thr(799) and the Lys(505)Thr(799) isoforms. In contrast, anti-Br(a) (HPA-5b) only recognized the Lys(505)Thr(799) form, whereas anti-Br(b) (HPA-5a) reacted with both Glu(505)Thr(799) and Glu(505)Met(799) isoforms. These results demonstrated that the Met(799) is responsible for formation of the Sit(a) alloantigenic determinants, whereas amino acid 505 (Lys or Glu) specifically controls the expression of Br(a) and Br(b) epitopes, respectively. Platelet aggregation responses of Sit(a) (+) individuals were diminished in response to collagen, indicating that the Thr(799)Met mutation affects the function of the GPIa/IIa complex.

Effect of C1-inhibitor in a rat model of necrotizing enterocolitis.

Our aim was to investigate the effect of C1-inhibitor (C1-INH) in a rat model of necrotizing enterocolitis (NEC). Twenty-four anesthetized and artificially ventilated rats received 0.1 mg/kg endotoxin. Fifteen minutes later, the animals in the study group (n = 12) were treated with 200 IU/kg C1-INH whereas the control animals (n = 12) received normal saline. In all animals, FiO(2) was reduced after 90 min from 0.21 to 0.05 and ventilation continued until 180 min or death. All animals developed shock symptoms. Drop in mean arterial blood pressure was more pronounced and survival time was shorter in the control group. Whereas the C1-INH activity increased in the study group, it decreased in the control group. The extent of macroscopic intestinal lesions did not differ between the groups. In conclusion, C1-INH did not prevent shock, but mitigated and delayed its course.

3-D ultrasound quantification of neonatal cerebral ventricles in different head positions.

We determined the influence of head position on lateral ventricular cerebral volume in low-birth-weight infants by three-dimensional (3-D) ultrasound (US). Thirty-nine neonates were examined prospectively in a controlled and blinded study. We used a freehand 3-D US system to acquire data sets after head positioning for 3 h on left and right side in random order. The borders of the lateral ventricles were marked in stored cross-sections. Volumes were calculated as mean of duplicate measurements. Median volume of lateral cerebral ventricles was 1.03 (quartiles 0.78-1.36) mL. Median left ventricular volume was slightly larger than right one (p = 0.13). Down-side lateral ventricles showed smaller volumes than up-side positioned ventricles (p < 0.01). Freehand 3-D US allows quantification of small volumes as neonatal lateral cerebral ventricles. Head position influences the lateral cerebral ventricle volume in low-birth-weight infants.

Thrombopoietin concentration in umbilical cord blood of healthy term newborns is higher than in adult controls.

Thrombopoietin (TPO) concentrations were determined in umbilical cord plasma of 121 healthy term newborns. The lower detection limit of the enzyme immunoassay employed was 32.5 pg/ml. Median cord plasma TPO concentration was 78 (interquartile range 55-107) pg/ml. 95th percentile was 255 pg/ml. In only 8% (10/121), TPO was below the detection limit compared to 81% of healthy adults (25/31). In cord blood and adult controls, there were no significant correlations of TPO with platelet count or mass.

3-D sonographic volume measurement of the cerebral ventricular system: in vitro validation.

This in vitro study evaluates the accuracy and observer dependency of a freehand three-dimensional (3-D) ultrasound system for measuring cerebral ventricular volume in infants. A sphere, a cylinder, and three cerebral ventricle phantoms were made of agarose and embedded in an echogenic matrix after measuring true volumes by water displacement. Volumes of the models were calculated by 3-D software after manual contour marking on ultrasound cross-sections. Mean +/- SD sonographic volume was 94.6%+/-7.3% (n = 130) of true volumes. Intraobserver variation (n = 10) was 2.3%-5.3% for complete investigation (scanning and marking), and 1.8%-4.1% for marking alone. Difference of means (n = 10) between two observers was 7.6% to 10.8% for complete investigation, and 0.6% to 1.6% for the marking process. We conclude that 3-D freehand ultrasonography may be useful for examining ventricle dilatation in infancy.

Acidosis activates complement system in vitro.

We investigated the in vitro effect of different forms of acidosis (pH 7.0) on the formation of anaphylatoxins C3a and C5a. Metabolic acidosis due to addition of hydrochloric acid (10 micromol/ml blood) or lactic acid (5.5 micromol/ml) to heparin blood (N=12) caused significant activation of C3a and C5a compared to control (both p=0.002). Respiratory acidosis activated C3a (p=0.007) and C5a (p=0.003) compared to normocapnic controls. Making blood samples with lactic acidosis hypocapnic resulted in a median pH of 7.37. In this respiratory compensated metabolic acidosis, C3a and C5a were not increased. These experiments show that acidosis itself and not lactate trigger for activation of complement components C3 and C5.

Complete blood counts from umbilical cords of healthy term newborns by two automated cytometers.

Complete blood counts (CBC) of umbilical cord blood from 123 healthy term newborns were simultaneously performed with two different cytometers using laser as a light source. Medians (95% range) were: WBC 14.2 (7.8-24.3) x 10(9)/l, platelets 265 (174-363) x 10(9)/l, Hb 15.7 (12.5-18.2) g/dl, RBC 4.6 (3.9-5.5) x 10(12)/l, MCV 106 (95-113) fl, PCV 0.49 (0.40-0.56), and MCH 33.8 (30.3-36.4) pg. Reticulocytes were 149 (95-212) x 10(9)/l or 3.3 (2.0-4.7)%; erythroblasts 5 (0-24) per 100 WBC or 0.53 (0.00-3.20) x 10(9)/l. The counters agreed well except for MCHC. WBC counts showed the smallest difference irrespective of erythroblast number; platelets showed the largest difference. The lower limit for normal Hb should be fixed at 12.5 g/dl for the adequate diagnosis of anaemia from cord blood of term newborns.

Anaphylatoxins in fresh-frozen plasma.

BACKGROUND: Fresh-frozen plasma (FFP) is widely used in patients with coagulation disorders and simultaneous complement activation. Complement activation in FFP itself is poorly investigated. STUDY DESIGN AND METHODS: The concentration of anaphylatoxins C3a and C5a, the complement precursors C1q and factor B, and complement function were measured in 40 consecutively administered FFP units in two pediatric neonatal intensive care units. In 12 samples, the measurements were also performed after incubation with inulin. RESULTS: In 15 of 40 FFP units, both anaphylatoxin concentrations were below the upper cutoff levels reported for healthy humans (C3a, 500 microg/L; C5a, 5 microg/L). Anaphylatoxin levels were higher in FFP units produced by apheresis than in those from blood donation. Complement activation of FFP by inulin increased anaphylatoxin concentration, whereas C1q and factor B levels, and complement function remained unchanged. CONCLUSION: Elevated concentrations of anaphylatoxin are frequently found in FFP units produced by apheresis. Studies are necessary to investigate the reasons for complement activation and the possibilities of prevention during apheresis. As the concentrations of complement precursors and complement function did not change with activation in FFP, these studies should include measurement of the anaphylatoxins C3a and C5a.

A point mutation leads to an unpaired cysteine residue and a molecular weight polymorphism of a functional platelet beta 3 integrin subunit. The Sra alloantigen system of GPIIIa.

Recently, we described a low frequency platelet alloantigen on human platelet membrane glycoprotein (GP) IIIa, termed Sra, that was involved in neonatal alloimmune thrombocytopenia. To identify the molecular nature of the Sra alloantigen, we analyzed the nucleotide sequence of polymerase chain reaction-amplified GPIIIa mRNA, and found a C2004-->T substitution in seven Sra positive individuals which results in an Arg636-->Cys polymorphism within the cysteine-rich region of GPIIIa. Analysis of allele-specific recombinant forms of GPIIIa that differed only at amino acid residue 636 showed that anti-Sra alloantibodies reacted with the Cys636, but not the Arg636, recombinant form of GPIIIa. Interestingly, under reducing conditions, the Cys636 form of GPIIIa migrated with a slightly increased apparent molecular weight compared with the Arg636 form. Following treatment with Endoglycosidase H, both allelic forms of GPIIIa exhibited the same mobility, however the Sra epitope was lost. Sra positive platelets express the same number of GPIIb-IIIa complexes on their surface as wild-type Sra negative platelets, and also aggregate normally in response to a variety of platelet agonists. Based upon these results, we conclude that 1) GPIIIa residue 636 specifically controls the formation and expression of the Sra alloantigenic determinant, and 2) an unpaired cysteine residue alters the N-linked glycosylation pattern of the extracellular domain of GPIIIa, but affects neither the degree of surface expression nor the adhesive function of the GPIIb-IIIa complex.

[A single base substitution is responsible for the origin of "private" platelet Sra antigens affects molecular weight polymorphism of glycoproteins IIIa]. / Eine einzelne Basensubstitution ist verantwortlich für die Entstehung des "privaten" Thrombozytenalloantigens Sra und führt zum Molekulargewichtspolymorphismus des Glykoproteins IIIa.

Some of the genetic polymorphisms of the platelet membrane glycoproteins (GP) IIIa are known to be responsible for alloantibody formation (Zw, Yuk). These antibodies may be involved in neonatal alloimmune thrombocytopenia, posttransfusion purpura, and sometimes in the state of refractoriness to platelet transfusion. Recently we described the first 'private' alloantigen on platelets residing on the 66-kDa membrane-bound fragment of GP IIIa. Further molecular genetic studies showed that the Sr polymorphism is associated with a C to T substitution at base 2004 in the GP IIIa gene resulting in an Arg/Cys amino acid dimorphism at position 636. Transfection of COS cells with recombinant forms of GP IIIa cDNA demonstrated that this amino acid dimorphism is responsible for the formation of the Sra epitope. Furthermore, the Sra variant of GP IIIa showed a slightly increased molecular weight which is presumably caused by different glycosylation.

The human platelet alloantigens Br(a) and Brb are associated with a single amino acid polymorphism on glycoprotein Ia (integrin subunit alpha 2).

The human GPIa/IIa complex, also known as integrin alpha 2 beta 1, serves as a major receptor for collagen in platelets and other cell types. In addition to its role in platelet adhesion to extracellular matrix, GPIa/IIa is also known to bear the clinically important Br(a) and Brb alloantigenic determinants, which can result in antibody-mediated platelet destruction. Immunochemical studies showed that the Br antigenic epitopes reside solely on the GP Ia subunit and do not depend on sialic acid residues. To define the polymorphism responsible for the Br alloantigen system platelet RNA PCR technique, was used to amplify GPIa mRNA transcripts. Nucleotide sequence analysis of the amplified platelet GPIa cDNA from Br(a/a) and Brb/b individuals revealed a single A<-->G polymorphism at base 1648. MnlI RFLP analysis of cDNA from serologically determined individuals confirmed that this polymorphism segregates with Br phenotype. This single base change results in a substitution of Lys (AAG) in Br(a) to Glu (GAG) in Brb at amino acid residue 505 In spite of the reversal in charge at this position, however, we found no difference in the ability of Bra and Brb homozygous platelets to adhere to collagens types I, III, or V, nor did anti-Bra or anti-Brb alloantibodies interfere with platelet adhesion to any of these fibrillar collagens. The identification of the nucleotide substitution that defines the Bra/Brb alloantigen system will now permit both pre- and postnatal diagnosis for Br phenotype.

[Complete remission of a highly malignant, progressive under therapy Wilm's tumor using the combination carboplatin and etoposide (VP 16)]. / Vollremission eines unter Therapie progredienten Wilms-Tumors hohen Malignitätsgrades durch die Kombination von Carboplatin und Etoposid (VP 16).

A Wilms' tumor in a 4 year old girl did not diminish under preoperative chemotherapy following SIOP 9/GPO study guidelines. Surgery revealed an anaplastic (high grade) nephroblastoma infiltrating pancreas, transverse colon, and diaphragm. During postoperative treatment with ifosfamide, vincristine, actinomycin D, and doxorubicin, there was massive tumor growth per continuitatem in chest and abdomen within 6 weeks. Following a French study for relapsed Wilms' tumor, we gave 160 mg/m2 carboplatin and 100 mg/m2 etoposide on 5 consecutive days. After only one cycle, the tumor showed already remarkable regress. We applied six cycles of carboplatin/etoposide and a abdominal radiation. At the end of therapy, the patient was in complete remission. Side effects of chemotherapy were severe bone marrow aplasia and a moderate and reversible decrease of creatinine clearance. The combination of carboplatin and etoposide is a promising therapy in Wilms' tumor resistant to classic nephroblastoma drugs like vincristine, doxorubicin, and actinomycin D.

Vitamin D dependent rickets type II with myelofibrosis and immune dysfunction.

We present a new patient with vitamin D dependent rickets type II. A 20-month-old Arabian boy whose parents are first cousins showed florid rickets, myelofibrosis and recurrent septicaemia. In addition to absent specific binding for 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). 25-Hydroxyvitamin D3-24-hydroxylase activity could not be induced in cultured fibroblasts. The patient did not respond to 99 micrograms 1,25(OH)2D3 per day, but skeletal and haematological abnormalities improved with daily infusion of 100 mg/kg calcium, as serum parathyroid hormone levels fell to normal values. At the age of 7 years, he died from pneumonia. The improvement of haematological abnormalities with calcium infusions but not with 1.25(OH)2D3 suggests a pathogenetic relationship of myelofibrosis and hyperparathyroidism. Having anti-lipid A IgM antibody titres up to 1:10.000 after Gram negative septicaemias, the patient never produced corresponding IgG antibodies. His neutrophil chemotaxis was persistently reduced to 57% +/- 3% of age-matched controls (P less than 0.028). The patient showed two pathological immune functions considered to contribute to the well-known susceptibility to infection in rickets.

[Controlled immunoglobulin therapy in immune hemolytic anemia by positive pool immunoglobulin fluorescence test]. / Gezielte Immunglobulintherapie einer immunhämolytischen Anämie bei positivem Pool-Immunglobulin-Fluoreszenz-Test.

An Italian boy with homozygous beta-thalassemia showed a shortening of transfusion intervals at the age of three years. He had a positive direct antiglobulin test (DAT) because of C3d-loaded red blood cells without any detectable erythrocytic antibody. Serologic investigations indicated a recent EBV infection. Pool immunoglobulin fluorescence test (PIT) revealed a loading of red blood cell membranes with antigens. Oral prednisone therapy did not show any effect. After a single infusion of 400 mg immunoglobulin per kg body weight decrease of hemoglobin concentration slowed down to the rate before crisis. DAT and PIT became negative. The immune hemolytic crisis was possibly due to erythrocyte loading with EBV antigen that caused activation of the alternate complement pathway. Detection of antigen loaded red blood cells by PIT suggested a immunoglobulin therapy in order to coat the structures promoting hemolysis. Thus, a positive PIT seems to be a criterion for successful application of immunoglobulins in immune hemolytic anemia.

Lymphocyte cell lines from vitamin D-dependent rickets type II show functional defects in the 1 alpha,25-dihydroxyvitamin D3 receptor.

Lymphocyte cell lines were established from five patients with vitamin D-dependent rickets, type II (VDDR-II). These lines were established by infection with human T-lymphotrophic virus type I (HTLV-I). Binding of [3H]1 alpha,25-dihydroxyvitamin D3 (1,25(OH)2D3) to its receptor in these cell lines was compared to binding studies using a T-lymphocyte cell line (S-LB1) from a normal individual. The 1,25(OH)2D3 receptor of S-LB1 was comparable to the well-characterized chick intestinal 1,25(OH)2D3 receptor in terms of its ligand binding affinity and capacity, its mobility on 5-20% sucrose gradients, and its adsorption to and elution properties from DNA-cellulose. Three cell lines established from patients with VDDR-II (Rh-VDR, Sh-VDR, and Ab-VDR) showed no specific binding of 1,25(OH)2D3 to a receptor and treatment of the cultured cells with 1,25(OH)2D3 did not stimulate production of 24,25-dihydroxy-vitamin D3 (24,25(OH)2D3), a response which is diagnostic of the presence of a functional 1,25(OH)2D3 receptor. In a fourth cell line, A1-VDR, the receptor for 1,25(OH)2D3 had a low binding capacity and 25(OH)D3-24-hydroxylase activity was not detectable. Induction of 24,25-(OH)2D3 synthesis by 1,25(OH)2D3 was observed in the fifth cell line, designated Ro-VDR, although the sensitivity to hormone treatment was lower than in the control cell line from a normal donor. The capacity of the receptor for 1,25(OH)2D3 was low in Ro-VDR. In all cell lines where 1,25(OH)2D3 binding to a receptor was detectable, the receptor had the typical sedimentation coefficient of 3.7 S on sucrose density gradient analysis. Binding and elution properties to DNA-cellulose, however, differed from normal in both Ro-VDR and A1-VDR cells where elution from DNA-cellulose occurred at a lower salt concentration than is typical of the 1,25(OH)2D3 receptor. While Ro-VDR cells showed typical nuclear localization of the unoccupied 1,25(OH)2D3 receptor, neither the unoccupied nor the occupied receptor from A1-VDR cells was completely localized in the nucleus. In a series of functional studies we found that modulation of the level of the mRNAs coding for both the c-myc oncogene and the growth factor known as granulocyte-monocyte colony stimulating activity by 1,25(OH)2D3 correlated with the 1,25(OH)2D3 receptor status of these cells. Use of these cell lines will facilitate further study of the molecular defect(s) in the receptor for 1,25(OH)2D3 in vitamin D-dependent rickets type II and will allow a correlation with impairment of cellular functions.