Biomedical subjects

H Ellemunter

Publications and source records attributed to H Ellemunter.

At least 19 recordsLinked to original sources

PubMed2001

Increased tacrolimus levels during diarrhea.

While it is well known that diarrhea results in decreased trough levels of cyclosporin A, experience with levels of tacrolimus (FK506) and diarrhea is limited. We have therefore measured the tacrolimus trough levels of four male and two female recipients of solid organs before, during, and after gastroenteritis. The average age of these six patients was 31 (1-60) years. Four patients had received a kidney transplant, one patient had undergone simultaneous kidney-pancreas transplantation, and another patient had received a liver transplant. Rotavirus was identified in the feces specimen of a 1-year-old child that had undergone liver transplantation. All patients showed an elevated tacrolimus trough level (peak 20-60 ng/ml) after onset of gastroenteritis. Under symptomatic therapy and adequate adjustment of tacrolimus dose, the gastroenteritis stopped and tacrolimus levels returned to the therapeutic range. We recommend that FK506 levels be carefully monitored during diarrhea in order to prevent intoxication.

Adolescent↗

PubMed2001

Rotavirus infection as cause of tacrolimus elevation in solid-organ-transplanted children.

Rotavirus (RV) is the most common cause of diarrheal illness in children. We report three solid-organ-transplanted patients in whom RV infection caused increased trough levels of the immunosuppressive macrolide tacrolimus (TAC) by mechanisms that are still under investigation. The virus was detected for longer in the feces of these patients than in infants not receiving immunosuppressive therapy. In association with short-term monitoring of blood trough levels of TAC, the dosage should be reduced early if symptoms of an acute gastroenteritis are present.

Adult↗

PubMed2001

Elevated tacrolimus trough levels in association with mycophenolate mofetil-induced diarrhea: a case report.

The combination of tacrolimus (TAC) and mycophenolate mofetil (MMF) is frequently used for immunosuppression after organ transplantation (Tx), but the pharmacokinetics and interactions between the two drugs are poorly elucidated. We describe here the increase of TAC trough levels during MMF-induced diarrhea in a 8-yr-old boy after kidney Tx. Early dose reduction of TAC, together with short-term monitoring of TAC trough levels in the presence of diarrhea, is recommended.

Child↗

PubMed2001

Chloride conductance and genetic background modulate the cystic fibrosis phenotype of Delta F508 homozygous twins and siblings.

To investigate the impact of chloride (Cl(-)) permeability, mediated by residual activity of the cystic fibrosis transmembrane conductance regulator (CFTR) or by other Cl(-) channels, on the manifestations of cystic fibrosis (CF), we determined Cl(-) transport properties of the respiratory and intestinal tracts in Delta F508 homozygous twins and siblings. In the majority of patients, cAMP and/or Ca(2+)-regulated Cl(-) conductance was detected in the airways and intestine. Our finding of cAMP-mediated Cl(-) conductance suggests that, in vivo, at least some Delta F508 CFTR can reach the plasma membrane and affect Cl(-) permeability. In respiratory tissue, the expression of basal CFTR-mediated Cl(-) conductance, demonstrated by 30% of Delta F508 homozygotes, was identified as a positive predictor of milder CF disease. In intestinal tissue, 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid-insensitive (DIDS-insensitive) Cl(-) secretion, which is indicative of functional CFTR channels, correlated with a milder phenotype, whereas DIDS-sensitive Cl(-) secretion was observed mainly in more severely affected patients. The more concordant Cl(-) secretory patterns within monozygous twins compared with dizygous pairs imply that genes other than CFTR significantly influence the manifestation of the basic defect.

Adolescent↗

PubMed2000

Congenital sodium diarrhea is an autosomal recessive disorder of sodium/proton exchange but unrelated to known candidate genes.

BACKGROUND & AIMS: Congenital sodium diarrhea (CSD) is caused by defective sodium/proton exchange with only 6 sporadic cases reported. The genetics of the disease have not been established. We studied 5 infants with secretory diarrhea, identified in a circumscribed rural area in Austria, to define the mode of transmission and the involvement of candidate genes known to encode for sodium/proton exchangers (NHEs). METHODS: We collected clinical and laboratory data from 5 affected patients, analyzed the pedigrees of their families, and performed homozygosity mapping and multipoint linkage analysis studies in 4 candidate regions known to contain NHE genes. RESULTS: The diagnosis of CSD in 4 of 5 patients was based on daily fecal sodium excretion between 98 and 190 mmol/L, hyponatremia, metabolic acidosis, and low-to-normal urinary sodium concentrations. Pedigree analysis of the affected 2 CSD families revealed parental consanguinity and a common single ancestor 5 generations ago. Homozygosity mapping and/or multipoint linkage analysis excluded the NHE1 locus on chromosome 1, NHE2 locus on chromosome 2, NHE3 locus on chromosome 5, and NHE5 locus on chromosome 16 as potential candidate genes for CSD in this pedigree. Results on NHE4 were inconclusive because the precise chromosomal location of this NHE gene in humans is currently unknown. CONCLUSIONS: Our data indicate that CSD is an autosomal recessive disorder but is not related to mutations in the NHE1, NHE2, NHE3, and NHE5 genes encoding for currently known sodium/proton exchangers.

Chromosome Mapping↗

PubMed2000

Distribution of rotavirus VP4 genotypes and VP7 serotypes among nonhospitalized and hospitalized patients with gastroenteritis and patients with nosocomially acquired gastroenteritis in Austria.

To assess the potential benefits of a reassortant tetravalent rotavirus vaccine, we investigated stool specimens from children in three different groups by reverse transcription-PCR (RT-PCR) for rotavirus G and P types: (i) children not hospitalized with community-acquired rotavirus-acute gastroenteritis (RV-AGE), (ii) children hospitalized for RV-AGE, and (iii) children with nosocomially acquired RV-AGE. From a total of 553 samples investigated, 335 were positive by enzyme-linked immunosorbent assay, of which 294 (88%) were positive by RT-PCR. Among the RT-PCR-positive samples, the predominant types were G1P[8] (84%), followed by G4P[8] (9%) and G3P[8] (2%). No differences between the three groups were observed, suggesting that community vaccination will diminish the most cost-relevant cases of hospitalizations and nosocomial infections.

Austria↗

PubMed1999

Unusual association of the DRB4 null allele, DRB40103102N, with HLA DRB10402 in a sample of Austrian patients.

Tissue typing for HLA class II antigens is routinely performed by serological, and/or DNA-based methods. Accuracy, absence of cross-reactivity and controllable level of resolution are striking advantages of molecular methods. However, a disadvantage of molecular typing, compared to serological methods, is the identification of unexpressed alleles. Whereas serology allows a more or less direct insight into antigen presence, molecular biology is an indirect method and results must also be interpreted by considering the biological pathways of protein expression. We believe that identification of nonexpressed MHC alleles is of importance for transplantation, since nonexpressed MHC allele positive individuals could give rise to antibody formation against the respective expressed MHC product in donor tissue. Usually, the nonexpressed DRB4*0103102N is encountered in association with DRB1*0701-DQB1*03032, which facilitates correct DNA typing. Here we describe the unusual association of this unexpressed DRB4*0103102N, with DRB1*0402-DQB1*0302 in a sample of Austrian patients.

Adult↗

PubMed1999

Bilateral nephrectomy, peritoneal dialysis and subsequent cadaveric renal transplantation for treatment of renal failure due to polycystic kidney disease requiring continuous ventilation.

We report here on a newborn with end-stage renal failure due to autosomal recessive polycystic kidney disease, also causing ventilation-requiring respiratory distress. Peritoneal dialysis was able to keep the newborn alive but not wean it from the respirator. After removal of both huge kidneys, dialysis became more effective and allowed the neonate to be extubated only 5 days later. It was decided to register the baby for a pediatric cadaveric kidney transplant when it reached 6 kg/body wt or to perform a living related transplant if no such kidney became available and the baby grew to 7 kg/body wt. At the age of 9 months and a weight of 6 kg a cadaveric kidney from a 20-month-old donor became available and was transplanted extraperitoneally. Prophylactic immunosuppression included cyclosporin, mycophenolate mofetil and steroids. Pneumonia on post-operative day 10 required respiratory care for several days and acute rejection requiring peritoneal dialysis. Both complications were controlled with antibiotics and conversion from cyclosporin to tacrolimus and a temporary increase in steroids. Thirteen months later the child is alive and well with a serum creatinine of 0.6 mg%. From this experience we would recommend early removal of both polycystic kidneys causing end-stage renal failure and respiratory insufficiency, starting peritoneal dialysis and performing a renal transplant as soon as possible. This therapeutic strategy seems appropriate for this complex situation.

Age Factors↗

PubMed1999

Chorea as the presenting clinical feature of primary antiphospholipid syndrome in childhood.

Three patients, aged five to 16 years, developed chorea as the only or main clinical manifestation of primary antiphospholipid syndrome. In two cases, complaints were self-limited five to eight months after onset. In one patient, the clinical course was complicated by valvulitis. Under corticosteroid treatment, chorea disappeared and cardiac involvement stabilised. Primary antiphospholipid syndrome is a probably under-recognised differential diagnosis of choreatic syndromes in childhood. Assessment of anticardiolipin antibodies and/or lupus anticoagulant should be an obligatory part of the diagnostic work-up of such patients. Early diagnosis of primary antiphospholipid syndrome may improve clinical management and prognosis.

Adolescent↗

PubMed1999

Intraosseous lines in preterm and full term neonates.

AIM: To evaluate the use of intraosseous lines for rapid vascular access in primary resuscitation of preterm and full term neonates. METHODS: Thirty intraosseous lines were placed in 27 newborns, in whom conventional venous access had failed. RESULTS: All the neonates survived the resuscitation procedure, with no long term side effects. CONCLUSION: Intraosseous infusion is quick, safe, and effective in compromised neonates.

Asphyxia Neonatorum↗

PubMed1998

Flow-cytometric evaluation of oxidative burst in phagocytic cells of children with cystic fibrosis.

OBJECTIVES: The objective of this study was to assess the dye 2', 7'-dichlorofluorescein (DCF) assay in screening for alterations in polymorphonuclear cell (PMN) and monocyte (MC) oxidative burst of cystic fibrosis (CF) patients. STUDY DESIGN: 56 CF patients aged between 2 and 20 years were investigated. Purified cells were stimulated with phorbolmyristate acetate (PMA) and zymosan (ZX). A range for DCF fluorescence for PMA- and ZX-stimulated and non-stimulated cells was established based on data from 60 healthy controls. RESULTS: PMNs showed both enhancement and impairment. A deficient oxidative burst was detected in a total of 14 CF patients caused by abnormally high mean fluorescence intensity (MFI) of resting cells. Enhanced oxidative burst was seen in 6 CF patients. CF patients responded differently to PMA or ZX stimulation. Pseudomonas aeruginosa colonization significantly enhanced (p<0.005) the MFI of resting PMNs. MCs of CF patients showed a significantly (p<0.05) enhanced oxidative burst after stimulation with PMA compared to healthy controls, but no differences could be observed after stimulation with ZX. Serum concentrations of interleukin-6 were elevated in all CF patients, in particular in those with activation of both PMNs and MCs. CONCLUSION: The DCF assay shows for the first time the heterogeneity of the oxidative burst reaction in CF patients. In our opinion, the DCF assay is a reliable method for detecting pathological oxidative burst in CF patients.

Adolescent↗

PubMed1998

Identification of a lipocalin in mucosal glands of the human tracheobronchial tree and its enhanced secretion in cystic fibrosis.

Members of the lipocalin protein family are characterized by their ability to bind small hydrophobic molecules. Some of them are known to be produced by various glands and secretory cells. Under certain conditions, these proteins would be ideally suited for clearance of lipophilic, potentially harmful substances and might also act as protection factors in airway secretions. We therefore used RT-PCR analysis with a set of oligonucleotide primers deduced from conserved regions of lipocalin members to identify specific RNA isolated from human trachea. With two of these oligonucleotide primers, a positive result was obtained. Sequencing of the RT-PCR products revealed that the DNA fragments were identical to the lipocalin 1 (LCN1) encoding cDNA. LCN1 is an unusual lipocalin member that binds a variety of lipophilic compounds and exhibits cysteine proteinase inhibitor and antimicrobial activities. The local production and topographic distribution of LCN1 in the human tracheobronchial tree was then investigated by immunoperoxidase staining on thin-layer sections using a specific antiserum. LCN1 was detectable in the acini of serous mucosal glands and sometimes within the glandular lumen, suggesting excretion of the protein. The latter finding was tested and verified by Western blot analysis of bronchial secretions of healthy individuals. Furthermore, the results of SDS-PAGE and Western blot analysis of bronchial secretions from patients with cystic fibrosis (CF), which are usually characterized by an increase of airway lipids, suggested that LCN1 secretion was enhanced. Northern blot analysis of RNA from normal trachea and RNA isolated from tracheal biopsies of patients with CF indicated that induced secretion was due to an up-regulated expression of the LCN1 gene. Thus, our investigations present the first clear evidence that LCN1 is induced in infection or inflammation and support the idea that this lipocalin functions as a physiologic protection factor of epithelia in vivo.

Adolescent↗

PubMed1997

Plasma vitamin C concentrations in patients with cystic fibrosis: evidence of associations with lung inflammation.

Vitamin C status and possible associations with the disease process in cystic fibrosis (CF) patients were investigated. Plasma vitamin C concentrations in patients from two different mid-European populations (Swiss, n = 62; Austrian, n = 60) taking no or low-dose vitamin C from multivitamin supplements did not differ from each other or from control subjects (n = 34). Vitamin C concentrations decreased with age (5.05 mumol.L-1, y-1). When followed up for 12 mo, patients had the highest plasma vitamin C concentrations in February and the lowest in May and August (P < 0.01); the decrease in vitamin C was accompanied by increases in plasma malondialdehyde (P < 0.001) and tumor necrosis factor alpha concentrations (P < 0.01). During supplementation with vitamin E for 2 mo or beta-carotene for 12 mo vitamin C concentrations did not change. They correlated inversely with white blood cell count (r = -0.36, P = 0.008), bands (r = -0.36, P = 0.02), alpha 1-acid glycoprotein (r = -0.45, P = 0.002), interleukin 6 (r = -0.46, P = 0.0006), and neutrophil elastase/alpha 1-proteinase inhibitor complexes (r = -0.34, P = 0.02). In patients with vitamin C concentrations < 40 mumol/L, all indexes of inflammation were relatively high, whereas those with concentrations > 80 mumol/L (upper quartile of control subjects) showed clearly lower values. These results are consistent with the hypothesis that by scavenging oxygen free radicals vitamin C interacts with an inflammation-amplifying cycle of activation of alveolar macrophages and neutrophils, release of proinflammatory cytokines and oxygen free radicals, and inactivation of antiproteases.

Adolescent↗

PubMed1997

Detection of 100% of the CFTR mutations in 63 CF families from Tyrol.

We identified 100% of the CFTR gene mutations, including three novel mutations, in 126 unrelated cystic fibrosis chromosomes from Tyrol, Austria. The frequency of the major mutation deltaF508 (74.6%) was not significantly different in Tyrolian CF-patients than in patients from Bavaria (71.0%) and Middle- and Northern Germany (71.9%), but was significantly higher than in patients from Styria (58.1%) or Northern Italy (47.6%). Interestingly, the distribution of the next most frequent mutations, R1162X (8.7%) 2183AA-->G, 2789+5G-->A and G542X (2.4% each), was more similar to the distribution of these mutations among CF-patients from Northern Italy than to those from Styria, Bavaria or Middle- and Northern Germany. Nine further mutations occurred once or twice. One of these, the missense mutation M1101K, is rare worldwide but very frequent in the Hutterite brethren, a small founder population which came from Southern Austria to Northern America. Three other different mutations (deltaL453, 1874insT and 4108delT) were present in single Tyrolian families and have not been described before. The identification of 100% of CFTR gene mutations in a particular CF population demonstrates the power of genetic analysis for the diagnosis and counselling of CF families in this restricted geographical area of Austria. Our study provides evidence for a closer genetic relation between CF patients from Tyrol and those from Bavaria or Middle- and Northern Germany as well as Northern Italy, than between CF patients from the two Austrian states Tyrol and Styria.

Adolescent↗

PubMed1997

Fibromuscular dysplasia of the internal carotid artery in a child with alpha-1-antitrypsin deficiency.

Fibromuscular dysplasia (FMD) is a non-inflammatory segmental arteriopathy of unknown origin. Most often the renal arteries are affected, however, also mesenteric, lumbar, vertebral, or carotid arteries may be involved. FMD has frequently been reported as a cause of stroke in adults, but very rarely in children. We report the case of an 11-year-old boy who presented with an ischaemic infarction in the anterior part of the territory of the left middle cerebral artery. Angiography demonstrated a 'string of beads' lesion suggestive of FMD causing occlusion at the origin of the middle artery. Laboratory analyses revealed the protease inhibitor (Pi) phenotype SZ (PiSZ) of alpha-1-antitrypsin deficiency as well as decreased antioxidants and signs of enhanced lipid peroxidation. Such an imbalance may be associated with diminished resistance to oxidation, possibly causing direct cellular and tissue injury. Whether alpha-1-antitrypsin deficiency and an impaired status of antioxidants, as seen in our patient, might play a role in the pathogenesis of FMD is presently unclear.

Antioxidants↗

PubMed1996

Circulating interleukin-1 receptor antagonist levels in neonates.

UNLABELLED: Circulating interleukin-1 receptor antagonist (IL-1 Ra) levels have been shown to reflect disease activity in certain conditions in adults. We determined circulating IL-1Ra references values for healthy neonates (healthy preterms and term infants with mild disease only) on days 2 (n = 17) and 4 of life (n = 23). Mean gestational age was 35 +/- 2.6 weeks. On the 2nd day of life IL1-Ra levels were 0.78 ng/ml (0.49/2.65), on day 4 0.38 ng/ml (0.20/0.48) (median, 25th/75th percentile, P = 0.01). The values were not influenced by gender. In neonates with severe illness (septicaemia, asphyxia, neonatal respiratory distress syndrome), who received invasive intensive care, circulating IL-1Ra levels were significantly higher than in the reference group of healthy newborns. On the 2nd day of life (14.72 ng/ml (4.38/18.67) versus 0.78 ng/ml (0.49/2.65), P < 0.0001; on day 4 of life, 3.38 ng/ml (0.80/11.99) versus 0.38 ng/ml (0.20/0.48), P < 0.005 (values are median; 25th/75th percentile, Mann-Whitney U-Wilcoxon Rank Sum W Test, two-tailed P). CONCLUSION: Compared to healthy individuals beyond the neonatal period, Il-1Ra concentrations are physiologically elevated within the first days of life and decline to low levels within days. In contrast, IL-1Ra levels are strikingly elevated in sick neonates.

Biomarkers↗

PubMed1996

ICln: a chloride channel paramount for cell volume regulation.

Cell volume regulation is a ubiquitous cell regulatory mechanism based on meticulously controlled ion transport mechanisms. Keeping the absolute volume constant seems to be of the highest priority for most cells and is achieved at the expense of altered intracellular ion concentrations. We have been able to demonstrate that ICln, a chloride channel cloned from epithelial cells, is paramount for the ability of swollen cells to regulate their volume back to that under resting conditions. A unique feature of ICln is the distinct sensitivity of these channels for nucleotides and nucleoside analogues added to the extracellular fluid. In addition, cromolyn sodium and nedocromil sodium, drugs used by patients with asthma, are able to impede the function of these channels.

Animals↗

PubMed1995

Transcript analysis of CFTR nonsense mutations in lymphocytes and nasal epithelial cells from cystic fibrosis patients.

The mutational effects at the mRNA level were investigated by RT-PCR analysis of nine different nonsense mutations (Q39X, E60X, R75X, G542X, L719X, Y1092X, R1162X, S1196X, W1282X) and one frameshift mutation (1078delT) within the CFTR gene. With the exception of mutation R1162X, reduced mRNA levels ranging from 30% to less than 5% of the wild type have been observed. In case of the R75X and E60X mutations, the mRNA reduction was accompanied by the appearance of atypical CFTR isoforms. Single exon 3 skipping, as well as joint exon 2 and 3 skipping, was observed in lymphocyte and nasal epithelial mRNA derived from R75X alleles. The analysis of mRNA transcribed from E60X alleles revealed skipping of exon 3 (lymphocytes and nasal epithelial cells) or skipping of exons 3 and 4 (nasal epithelial cells). With the exception of the E60X mutation, no obvious tissue-specific differences in the splicing pattern and ratios of mutation to wild-type transcripts were detected between lymphocytes and nasal epithelial cells. In addition to aberrant splicing, the reduction of transcripts is the most common effect of nonsense and frameshift mutations within the CFTR gene.

Alleles↗