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Biomedical subjects

C Bührer

Publications and source records attributed to C Bührer.

At least 19 recordsLinked to original sources
PubMed2005

Low soluble Fas (sFas) and sFas ligand (sFasL) content in breast milk after preterm as opposed to term delivery.

AIM: Various mechanisms of innate immunity and gastrointestinal integrity are potentially affected by soluble Fas (sFas) and sFas ligand (sFasL). Assuming that sFas and sFasL in milk reflect cellular events during lactogenesis, we aimed to assess the impact of premature parturition and duration of lactation on the concentrations of sFas and sFasL in human milk. PATIENTS AND METHODS: The content of the soluble form of the cell surface receptor Fas (sFas) and its natural ligand (sFasL) was measured in human breast milk of 44 healthy mothers after preterm (<35 wk, n=21) and term (>37 wk, n=23) delivery. Milk was furthermore classified as immature breast milk (days 4-7 of lactation) or mature breast milk (days 35-45 of lactation). Breast milk (2-3 ml) was sampled 5 min after the start of breastfeeding by manual expression or milk pump, and stored at -20 degrees C until analysis by an ELISA. RESULTS: sFas and sFasL concentrations were lower in immature milk after preterm compared to term delivery (sFas: 1.71; 1.38-2.47 ng/ml vs 3.03; 2.02-4.30 ng/ml, p < 0.001; sFasL: 0.13; 0.07-0.21 ng/ml vs 0.29; 0.15-0.60 ng/ml, p < 0.001 [median +/- interquartile range]). Mature milk samples, taken 1 mo later from both gestational groups, did not differ in sFas/sFasL content. Soluble Fas was positively correlated with sFasL in the same sample of immature (p < 0.001) and mature human milk (p < 0.05). A positive correlation was found between sFas and sFasL in immature and mature milk samples of the same mother (p < 0.01). The body mass index of the mothers and duration of pregnancy were positively correlated with the sFas and sFasL content in immature milk (p < 0.05 and p < 0.01, respectively) but not in mature milk. CONCLUSION: Preterm newborn infants fed with breast milk have a lower intake of sFas and sFasL compared to term neonates. Our results demonstrate that preterm delivery affects breast milk composition.

Adult↗
PubMed2003

Neurodevelopment at 1 year of age in infants with congenital heart disease.

OBJECTIVE: To assess psychomotor development and neurological sequelae in infants after surgery for congenital heart defects. DESIGN AND SETTING: Single institution prospective cohort study. PATIENTS: 90 of 112 consecutive surviving infants of less than 1 year of age, without brain anomalies, conditions, or syndromes associated with delayed mental development, who underwent cardiac surgery during an 18 month period; 20 control infants with minor or no congenital heart defects. MAIN OUTCOME MEASURES: Griffiths developmental scales and standardised neurological examination at 1 year. RESULTS: Mean (SD) developmental quotient (DQ) in index infants was 99 (10.6), compared with 106.7 (6.6) in controls (p < 0.001). DQ was lower in infants after palliative surgery (n = 16; 88 (12.2)) than after corrective surgery (n = 74; 101.4 (8.6)) (p < 0.001). Of the 90 index infants, 24 (27%) had a DQ below 93.5 (more than 2 SD below the mean of controls). Developmental delay (DQ < 93.5) was more common after palliative surgery (10/16, 63%) than after corrective surgery (14/74, 19%) (p < 0.001). Of the 90 index infants, 29 (32%) had neurological abnormalities, compared with only one of the 20 controls (5%) (p = 0.013). Neurological abnormalities were more frequent after palliative surgery (11/16, 69%) than after corrective surgery (18/74, 24%) (p < 0.001). CONCLUSIONS: There is a considerable rate of neurodevelopmental impairment at 1 year of age in infants after cardiac surgery. Psychomotor impairment and neurological sequelae are apparently more severe in infants in whom only palliative surgery is possible.

Cohort Studies↗
PubMed2002

Use of 2% 2-phenoxyethanol and 0.1% octenidine as antiseptic in premature newborn infants of 23-26 weeks gestation.

In preterm newborn infants, topical iodine-containing antiseptics disturb thyroid hormone regulation while alcohol-based disinfectants may cause local burns. We therefore investigated the use of an aqueous solution containing 0.1% octenidine and 2% 2-phenoxyethanol for skin disinfection during the first seven days of life in premature newborns with a gestational age <27 weeks who were consecutively admitted to our level III neonatal intensive care unit between November 1, 2000 and December 31, 2001 (N=24). In boys. (N=13) the renal excretion of absorbed 2-phenoxyethanol and its metabolite 2-phenoxyacetic acid was quantitated by high-pressure liquid chromatography. In the most immature newborn (gestational age 23 6/7 weeks), a transient erythematous reaction was observed following application of the octenidine/phenoxyethanol solution prior to umbilical vessel catheterization. No other local reactions were observed. The urinary concentration of 2-phenoxyethanol was <2 ppm in all samples, while urinary 2-phenoxyacetic acid concentrations reached 5-95 ppm (median 24 ppm). One infant had a culture-proven septicaemia (Bacillus species) during the first seven days of life. We conclude that, in contrast to alcohol-based antiseptics, an aqueous solution of 0.1% octenidine and 2-phenoxyethanol does not cause major skin damage in premature newborn infants <27 weeks' gestation. 2-Phenoxyethanol is readily absorbed by the newborn's skin but apparently undergoes extensive oxidative metabolization to 2-phenoxyacetic acid.

Anti-Infective Agents, Local↗
PubMed2001

Elevated nerve growth factor and neurotrophin-3 levels in cerebrospinal fluid of children with hydrocephalus.

BACKGROUND: Elevated intracranial pressure (ICP) resulting from impaired drainage of cerebrospinal fluid (CSF) causes hydrocephalus with damage to the central nervous system. Clinical symptoms of elevated intracranial pressure (ICP) in infants may be difficult to diagnose, leading to delayed treatment by shunt placement. Until now, no biochemical marker of elevated ICP has been available for clinical diagnosis and monitoring. In experimental animal models, nerve growth factor (NGF) and neurotrophin-3 (NT-3) have been shown to be produced by glial cells as an adaptive response to hypoxia. We investigated whether concentrations of NGF and NT-3 are increased in the CSF of children with hydrocephalus. METHODS: NGF was determined in CSF samples collected from 42 hydrocephalic children on 65 occasions (taps or shunt placement surgery). CSF samples obtained by lumbar puncture from 22 children with suspected, but unconfirmed bacterial infection served as controls. Analysis was performed using ELISA techniques. RESULTS: NGF concentrations in hydrocephalic children were over 50-fold increased compared to controls (median 225 vs 4 pg/mL, p < 0.0001). NT-3 was detectable (> 1 pg/mL) in 14/31 hydrocephalus samples at 2-51 pg/mL but in none of 11 control samples (p = 0.007). CONCLUSION: NGF and NT-3 concentrations are increased in children with hydrocephalus. This may represent an adaptive response of the brain to elevated ICP.

Adaptation, Physiological↗
PubMed2001

Adhesion molecules in different treatments of acute myocardial infarction.

BACKGROUND: Tissue damage after ischemia and reperfusion involves leukocyte endothelial interactions mediated by cell adhesion molecules. This study was designed to determine the time course of soluble adhesion molecules in patients with acute myocardial infarction after attempted reperfusion by thrombolysis with tissue plasminogen activator (tPA) or streptokinase (SK), or percutaneous transluminal coronary angioplasty (PTCA). METHODS: In 3 x 10 randomly selected patients with acute myocardial infarction undergoing thrombolysis with tPA or SK, or treated with PTCA, plasma concentrations of soluble L-selectin, P-selectin, E-selectin, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and platelet endothelial cell adhesion molecule-1 (PECAM-1) were measured by enzyme-linked immunosorbent assay, 30 min and 1, 2, 4, 8, 12 and 24 hours after intervention. RESULTS: After thrombolysis with tPA, soluble L-selectin concentrations were persistently depressed and soluble PECAM-1 concentrations were elevated, compared with controls, SK and PTCA. While soluble VCAM-1 concentrations did not differ within the first hours after interventions between the three groups, soluble VCAM-1 rose by 24 hours after tPA thrombolysis but did not increase after SK and PTCA treatment. Soluble ICAM-1 concentrations were consistently elevated after PTCA compared with controls and thrombolysed patients. Soluble E-selectin was depressed after tPA thrombolysis and PTCA in comparison with controls, while the SK group showed an increase throughout the observation period. Soluble P-selectin was increased after PTCA and SK lysis up to 8 hours after treatment compared with controls, but no significant differences could be found between treatment groups. CONCLUSION: Adhesion molecules mediating leukocyte endothelial interactions are altered subsequent to postischemic reperfusion and by treatment with thrombolytic agents and angioplasty. The clinical relevance of these biological changes remains to be determined.

Adult↗
PubMed2001

Early expression of glutamate transporter proteins in ramified microglia after controlled cortical impact injury in the rat.

Traumatic brain injury is followed by increased extracellular glutamate concentration. Uptake of glutamate is mainly mediated by the glial glutamate transporters GLAST and GLT-1. Extent and distribution of GLAST and GLT-1 were studied in a rat model of controlled cortical impact injury (CCII). Western Blot analysis revealed lowest levels of GLAST and GLT-1 with a decrease by 40%-54% and 42%-49% between 24 and 72 h posttrauma. By 8 h after CCII, CSF glutamate levels were increased (10.5 microM vs. 2.56 microM in controls; P < 0.001), reaching maximum values by 48 h. A significant increase in de novo GLAST and GLT-1 expressing ramified microglia was observed within 4 h, reached a stable level by 48 h, and remained high up to 72 h after CCII. Furthermore, ramified microglia de novo expressed the neuronal glutamate transporter EAAC1 after CCII. Following CCII, GLAST/GLT-1 and GFAP coexpressing astrocytes were immediately reduced, reaching minimum levels within 8 h. This reduction of expression could be either due to protein downregulation or loss of astrocytes. At 72 h, a marked population of GLAST- and GLT-1-positive reactive astrocytes appeared. These results support the hypothesis that reduced astrocytic GLAST and GLT-1 protein levels following CCII contribute to evolving secondary injury. Microglia are capable of de novo expressing glutamate transporter proteins, indicating that the expression of glial and neuronal glutamate transporters is not restricted to a specific glial or neuronal lineage. Ramified microglia may play an important compensatory role in the early regulation of extracellular glutamate after CCII.

ATP-Binding Cassette Transporters↗
PubMed2001

Colonic pneumatosis intestinalis in preterm infants: different to necrotising enterocolitis with a more benign course?

UNLABELLED: Necrotising enterocolitis (NEC) is the predominant immaturity-associated disease of the bowel in the preterm neonate and leads to substantial mortality and long-term morbidity. Diagnostic features of NEC include, apart from the clinical presentation, laboratory and radiological parameters. Pneumatosis intestinalis (PI) on abdominal radiographs is regarded as a criterion of definitive proof for this disease entity. The objective of this presentation is to link the topographic pattern of PI to the clinical course in cases of suspected NEC. We report two cases of radiological appearance of colonic PI indicative of NEC without associated laboratory and/or macroscopic evidence of the disease, and with minor clinical symptoms only. Data from animal studies indicate that decreased blood supply to the small bowel is associated with more extensive bowel damage as compared to impaired colonic perfusion. Therefore the topographical distribution of PI might be a more specific sign as the general presence or absence of PI. CONCLUSION: The topographical pattern of pneumatosis intestinalis may be predictive of the clinical course of inflammatory bowel disease in preterm infants.

Diagnosis, Differential↗
PubMed2001

Hyperoxia- and hypoxia-mediated activation of polymorphonuclear leukocytes: a comparison of cord and adult venous blood.

BACKGROUND: Among the most prominent changes occurring in newborn infants is the exposure of tissues and blood cells to increased oxygen tension. This increase is even more pronounced in neonatal resuscitation using 100% oxygen, currently recommended in the published guidelines. OBJECTIVE: To analyse the response of neonatal and adult polymorphonuclear neutrophils (PMN) to high or low oxygen tension in vitro. MATERIALS: Neonatal cord blood and adult venous blood without previous contact to ambient air was exposed to 0, 21, or 100% oxygen for 30 min followed by incubation for up to 24 h. METHODS: Flow cytometry was used to assess PMN activation as indicated by downregulation of L-selectin expression. Cell viability was quantified by the amount of propidium iodide uptake. RESULTS: In adult PMN, L-selectin downregulation was greatly accelerated by hypoxia (PO2=27.2+/-3.4 mmHg) compared with both normoxia (PO2=71.0+/-11.0 mmHg) or hyperoxia (PO2=653.2+/-9.4) (P<0.05). In contrast, hyperoxia was the most potent stimulus for cord blood PMN, compared with both normoxia and hypoxia (P<0.05). Evidence of necrosis as indicated by positive staining for propidium iodide was similar in cord blood (10 h: 5.83% in oxygen) and in adult blood (10 h: 6.45% in oxygen). No differences were found between exposure to hypoxia, normoxia, or hyperoxia. CONCLUSION: Oxygen exposure of neonatal PMN leads to a more pronounced activation as compared with adult cells. Exposure towards high concentrations of oxygen may contribute to inflammatory processes during early neonatal life.

Adult↗
PubMed2001

Early cessation of breast milk feeding in very low birthweight infants.

This investigation was carried out to comparatively assess the duration of breast milk feeding and to analyze risk factors for early cessation of breast milk feeding in term and very preterm infants. A cohort study was performed in 89 consecutive very low birthweight (VLBW) infants (<1500 g) who survived for at least for one week, and 177 term infants with birthweights >2500 g born in the same hospital matched for gender and multiplicity. Median duration of breast milk feeding, as determined from charts and questionnaires mailed to the mothers at 6 and 12 months corrected age, was 36 days in VLBW infants, compared to 112 days in control infants (P<0.0001). In both VLBW and control infants, smoking during pregnancy, low maternal and low paternal school education were each significantly associated with short duration of breast milk feeding. In VLBW infants, multiple pregnancy and gestational age <29 weeks were each associated with prolonged breast milk feeding, as were maternal age >35 years and spontaneous pregnancy (as opposed to pregnancy following infertility treatment) in term infants. Multivariate analysis revealed that VLBW, smoking and low parental school education were independent negative predictors of breast milk feeding. While these results emphasize the need for special support of VLBW infant mothers promoting lactation, the relationships between smoking, school education and breast milk feeding in both strata show that efforts to increase breast milk feeding require a public health perspective.

Breast Feeding↗
PubMed2001

Familial recurrence of spontaneous fetal intracranial hemorrhage: ultrasonographic diagnosis and postnatal magnetic resonance imaging (MRI).

We report fetal intracranial hemorrhage in term siblings from consanguineous parents, spontaneously occurring in the third trimester of pregnancy. Prenatal ultrasound in one case and postnatal MRI in both demonstrated massive parenchymal bleeding involving large areas of the cerebral cortex, white and gray matter. Vasculopathies, vascular malformations, coagulopathies, thrombocytopenia and relevant metabolic disorders could be excluded.

Brain↗
PubMed2001

Increased cerebrospinal fluid concentrations of soluble Fas (CD95/Apo-1) in hydrocephalus.

BACKGROUND AND AIMS: The ventricular enlargement observed in children with chronically raised intracranial pressure (ICP) causes a secondary loss of brain tissue. In animal studies of hydrocephalus, programmed cell death (apoptosis) has been found as a major mechanism of neuronal injury. One of the regulators of the apoptotic cell death programme is the receptor mediated Fas/Fas ligand interaction. METHODS: The apoptosis regulating cytokines soluble Fas (sFas) and soluble Fas ligand (sFasL) were studied in the cerebrospinal fluid (CSF) of 31 hydrocephalic children undergoing shunt surgery for symptomatic hydrocephalus and 18 controls. RESULTS: High concentrations of sFas were observed in children with hydrocephalus (median 252 ng/ml); in controls sFas was below the detection limit (0.5 ng/ml). sFasL was undetectable in all but one sample. CONCLUSION: High concentrations of sFas in the CSF of children with hydrocephalus suggest intrinsic sFas production, potentially antagonising pressure mediated Fas activation.

Adolescent↗
PubMed2001

Patent ductus arteriosus in very low birthweight infants: complications of pharmacological and surgical treatment.

AIMS: To evaluate complications of surgical and pharmacological treatment of symptomatic patent ductus arteriosus (PDA) in very low birthweight (VLBW) infants. PATIENTS AND METHODS: Of 931 VLBW infants consecutively admitted 1987-1998, a significant PDA prompted first-choice treatment by indomethacin in 101 infants, and surgery in 55 infants. PDA closed or became asymptomatic after indomethacin in 64 patients (63%), while 34 went on to surgery. PDA closure was achieved in all 61 infants after ligation and in 26 of 28 infants after clipping. RESULTS: Transient renal impairment after indomethacin treatment was recorded in 40 of 101 infants (40%), compared to renal impairment in 9 of 55 infants (16%) undergoing surgery without prior indomethacin. No differences in necrotizing enterocolitis and intracranial hemorrhage rates were seen. Air leak occurred in 6 of 89 infants after surgery, two of which had fatal tension pneumothorax. Intraoperative hemorrhage requiring emergency transfusion occurred in 2 infants, wound infection occurred in 2 infants and phrenic palsy in one infant. Based on an intention-to-treat analysis, the overall fatality rates were 16 of 101 (16%) for indomethacin and 14 of 55 (25%) for surgery. CONCLUSIONS: Despite the short-comings inherent to retrospective analyses, we propose that surgery should be reserved for infants not responding to pharmacological PDA closure.

Birth Weight↗
PubMed2001

Role of erythromycin for treatment of incipient chronic lung disease in preterm infants colonised with Ureaplasma urealyticum.

Ureaplasma urealyticum is frequently isolated from tracheal aspirates of very low birthweight infants who go on to develop chronic lung disease. The use of erythromycin has been advocated in ventilated very low birthweight infants who are colonised with U. urealyticum, although the association between U. urealyticum and chronic lung disease remains controversial. There are only two randomised, controlled trials involving a total of 37 U. urealyticum-positive very low birthweight infants. Both trials failed to demonstrate a reduction in the incidence of chronic lung disease after 7 or 10 days of erythromycin. On the other hand, there are reports of rare but serious adverse effects of erythromycin in newborn infants including sudden cardiovascular compromise and hypertrophic pyloric stenosis. We conclude that, at present, there is insufficient evidence to support the use of erythromycin for the treatment of incipient chronic lung disease in very low birthweight infants colonised with U. urealyticum.

Anti-Bacterial Agents↗
PubMed2001

Breast milk from mothers of very low birthweight infants: variability in fat and protein content.

UNLABELLED: While breast milk appears to be superior to formula for the development of very low birthweight (VLBW) infants, it is supplemented to meet the metabolic demands of the rapidly growing premature infant. To estimate the nutritional variability of breast milk from mothers of VLBW infants, protein (bicinchoninic acid method) and fat content (creamatocrit) were measured in breast-milk spot samples from mothers of 20 VLBW infants, collected 4 times a day during the first 4 wk of lactation. Protein content (median 1.9 g dl(-1), range 1.1-3.5 g dl(-1)) and fat content (3.8/1.0-14.6 g dl(-1)) were highly variable and lacked a normal distribution over all samples and in individual women's milk. There was only a weak correlation between fat and protein (rs=0.416, p < 0.001). Fat but not protein was lower in morning samples than in samples collected later in the day (p < 0.001). Protein but not fat content decreased during the weeks of lactation (rs =-0.446, p < 0.001). No impact of the baby's gestational age was observed. CONCLUSION: The fat and protein content of breast milk from mothers of VLBW infants is highly variable, calling into question the clinical feasibility of individualized supplementation of breast milk for VLBW infants based on spot sample measurements.

Adult↗
PubMed2000

Oral isobutyramide reduces transfusion requirements in some patients with homozygous beta-thalassemia.

The butyrate derivative isobutyramide (IBT) increases fetal hemoglobin (HbF) in patients with beta-hemoglobinopathies, but little is known about its usefulness for prolonged therapeutic use. We treated 8 patients with transfusion-dependent beta-thalassemia with 350 mg/kg of body weight per day of oral IBT for 126 to 384 days. During the trial period, the hemoglobin level was maintained between 85 g/L (range 82-87 g/L) (pretransfusion) and 115 g/L (range 110-119 g/L) (post-transfusion) (median, interquartile range), corresponding to 4-week transfusion intervals in all patients during the pretreatment phase. Adverse effects (bitter taste, epigastric discomfort) did not cause discontinuation of IBT. HbF increased in all patients from 3.1% (range 1.9%-4.8%) to 6.0% (range 3.3%-8.7) (P =.0017), while free Hb dropped from 0.48 g/L (range 0.39-0.81 g/L) to 0.19 g/L (range 0.16-0.24 g/L) (P <.0001). Transfusion intervals were consistently extended to 8 or 9 weeks in 1 patient, resulting in a decrease of daily iron load from 455 microgram/kg per day (range 451-459 microgram/kg per day) before therapy to 211 microgram/kg per day (range 203-286 microgram/kg per day) during the 12-month treatment period. Prolongation of transfusion intervals achieved by IBT was less consistent in another patient, whose parenteral iron load nevertheless decreased from 683 microgram/kg per day (range 618-748 microgram/kg per day) to 542 microgram/kg per day (340-596 microgram/kg per day). In the other 6 patients, no prolongation of transfusion intervals was achieved. Response to treatment was associated with high pretreatment HbF (> 4.5%), high parental HbF, and increased erythropoietin levels (> 150 IU/L). We conclude that IBT prolongs transfusion intervals and reduces parenteral iron burden in some patients with transfusion-dependent beta-thalassemia.

Administration, Oral↗