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Biomedical subjects

J Forster

Publications and source records attributed to J Forster.

At least 217 records · Page 12Linked to original sources

Increased serum urate in galactosemia patients after a galactose load: a possible role of nucleotide deficiency in galactosemic liver injury.

Five galactosemic and 5 normal children received an oral load of galactose under standardized conditions. The maximal blood galactose level after 1.5 hours was 12.6 +/- 2.0 (S.D.) mmol/l in individuals with a deficiency of uridylyl transferase (EC2.7.7.12) as compared to 5.8 +/- 1.2 (S.D.) mmol/l in the controls. The concentration of serum urate in galactosemics increased to 155% of the fasting level (P less than 0.005); no rise was detectable in the controls. The elimination of urate with the urine was augmented by the same amount in both groups. Our studies provide evidence for an increased catabolism of hepatic nucleotides. This may lead to a deficiency of nucleotides which is proposed as a cause of galactosemic liver injury.

Blood Glucose↗

Magnetization transfer contrast of hepatic lesions in breath-hold gradient-echo images of different T1 weighting.

Seventeen patients with hepatic lesions [six metastases from colon, breast, and gallbladder carcinoma; one gallbladder carcinoma; five hepatocellular carcinoma; three focal nodular hyperplasia (FNH); one adenoma; and one cyst] were examined by MR breath-hold two-dimensional gradient-echo imaging to assess the potential of magnetization transfer contrast (MTC) for improved conspicuity and classification. Imaging sequences were applied with and without irradiation of off-resonant radiofrequency (RF) prepulses, but other parameters were unchanged. Therefore, quantitative assessment of MTC could be performed. In contrast to former examinations of other researchers, no significant difference of MTC was found between malignant liver lesions and benign lesions as FNH or adenoma. MTC might provide differentiation between hemangioma and cysts versus solid tumors, but MTC is not capable of distinguishing benign and malignant types of solid liver tumors. Effects of unchanged MTC prepulses on signal intensity of normal liver tissue and most lesions were more pronounced for nearly proton density-weighted fast low-angle shot (FLASH) images than for T1-weighted FLASH images, obtained by using higher excitation flip angles. Liver-to-lesion contrast could not be improved clearly by MTC prepulses. The contrast between liver and lesions in the gradient-echo breath-hold images was compared with standard T1- and T2-weighted spin-echo images. Liver-to-lesion contrast in the breath-hold images was found to be inferior to T2-weighted spin-echo images in 14 of 17 cases. Lesion conspicuity in regions near the diaphragm was better in breath-hold images, because problems with marked breathing motion (as in standard imaging) could be avoided.

Adult↗

Slice-selective fat saturation in MR angiography using spatial-spectral selective prepulses.

Presaturation of fat signals by frequency-selective radiofrequency (RF) pulses is often applied in MR angiography to improve the visualization of the blood vessels. Unfortunately, standard fat saturation methods might cause a considerable reduction of the blood signal in the measured slices. This effect is caused by an attenuation of blood magnetization in remote tissue regions with water protons showing a similar Larmor frequency as the fat protons in the recorded slice. The affected blood water protons subsequently flow into the recorded slice and provide low signal intensity. Suitable spatial-spectral selective methods for slice-selective fat saturation were developed to avoid this unwanted effect. A spatial-spectral fat saturation technique was compared with a corresponding only spectrally selective approach. Both saturation techniques were included in a standard two-dimensional (2D) cine sequence and applied in angiographic examinations of the thighs. The results indicate that spatial-spectral saturation (acting slice selectively) leads to a clearly higher blood signal intensity in fat-suppressed MR angiography compared with standard techniques, especially in measurements performed during the systolic phase of the cardiac cycle.

Adipose Tissue↗

Improved clinical echo-planar MRI using spatial-spectral excitation.

Echo-planar imaging (EPI) is markedly susceptible to B0 field distortions and to frequency differences caused by chemical shift, because the phase of the signals is accumulating during the acquisition train. Thus, only water proton signals are usually recorded after frequency-selective suppression of the fat portions of magnetization. Otherwise, a shifted signal frequency from fat results in ghosting artifacts. In this article, a technique is presented working with spatial-spectral excitation for highly selective water or fat EPI. The proposed method allows recording in multislice operation on EPI scanners without irregular gradient or RF pulse shapes. Examples of gradient-echo and spin-echo EPI using spatial-spectral excitation by series of two to eight single slice-selective RF pulses are demonstrated. The method is not sensitive to misadjustments or inhomogeneities of the B1 field, but sufficient homogeneity of the static magnetic field B0 is required. Especially the quality of diffusion-weighted echo-planar images can be markedly improved by the new technique compared to conventional EPI, because artifacts from undesired chemical shift components are completely avoided.

Adult↗

Prevalence of antibodies against HEp-2 cell antigen in infants and children hospitalized with respiratory syncytial virus infection.

Infants with respiratory syncytial virus (RSV) infection were shown to have antibodies against HEp-2 cell antigen present in RSV-antigen preparation used for immunoblot analysis. The prevalence of anti HEp-2 cell antibodies was examined in infants hospitalized for RSV infection (n = 49, median age 121 days) compared to rotavirus infected children (n = 30, median age 114 days) and to healthy controls (n = 20, median age 150 days). The immunoblot analysis with RSV-infected and non-infected HEp-2 cells as antigen revealed the expected age-dependent low prevalence of G protein antibodies and clear seroconversion of N and P protein antibodies. HEp-2 antibody prevalence was higher in RSV antigen-positive infants (33/49) than in rotavirus antigen-positive (5/30) and RSV antigen-negative infants (4/20), respectively (p < 0.001). Anti HEp-2 antibodies were mostly directed against 47, 46, 33, 30 kD antigens. A multiple regression analysis found the following correlations (odds ratio; 95% confidence interval): 42 kD RSV antibodies (N protein) with pneumonia (7.58; 1.43-40), 94 kD RSV antibodies (G protein) with bronchiolitis (0.064; 0.006-0.686). This study shows repeated well-known features of humoral immunity in RSV infection. The data on anti HEp-2 antibodies point to a role for these pre-existing autoreactive antibodies in the pathogenesis of RSV infection.

Acute Disease↗

[Characteristics of a target population for preventing house-dust mite allergy in toddlers].

AIM: To evaluate a recruitment strategy to identify high risk toddlers for a programme of prevention of allergy. For screening, parents were asked to participate in our study by information form and screening questionnaire on the occasion of routine check-up visits of toddlers scheduled between 20 and 48 months of age in four paediatric practices. As a next step, readiness of parents for implementation of preventive measures was confirmed. METHOD: Inclusion criteria were age between 20 and 48 months and a positive atopic family history (evaluated by 5 questions regarding asthma, allergic rhino-conjunctivitis and atopic dermatitis) of parents or siblings. This was confirmed by sensitization to an environmental allergen (skin prick test (SPT)) in at least one parent. If these inclusion criteria were fulfilled, the toddlers were randomly allocated to the intervention and control group of the prevention programme. RESULTS: 111 of 175 screening questionnaires (63.4 %) were returned. In 76.6 % (n = 85) of these 111 questionnaires a positive atopic family history (mother, father, sibling) was noted. All inclusion criteria were fulfilled by only 43 toddlers (age: median 33.6 months, 5-95 % quantile: 21.6-48 months). Based on the positive screening questionnaire, history of atopy was confirmed by positive SPT in 70.0 % of fathers and 77.8 % of mothers. Despite a negative screening questionnaire, history of atopy was detected by a positive SPT in 11.1 % of mothers and 47.4 % of fathers. Detection of specific IgE against house-dust mite in 9 of 18 serum samples revealed the risk for allergy of the toddlers. A re-evaluation after three months showed that all the elements of the prevention programme as well as the recommendations for the control group had been almost completely accepted by all the families concerned practically without any reservations. CONCLUSION: The recruitment of toddlers with high risk for developing allergy turned out well and could be validated. The prevention programme was readily accepted by the families and thus can be used for a larger study.

Antigens, Dermatophagoides↗

RSV-prevention in children guided by a web-based early warning system.

BACKGROUND: Passive immunization with palivizumab is expensive and requires considerable logistic effort. So far 5 monthly injections from November to March are recommended. The RSV season onset and its duration, however, shows considerable variation. In many countries on the northern hemisphere a dual rhythm is described. METHOD: A web-based early warning system within the research network PID-ARI.net is in place since 2002. The surveillance data are published online weekly via www.pid-ari.net. This enables physicians to carry out interventions, like passive immunization for RSV, synchronously with the epidemiology of a given pathogen instead of a rigid schedule. The surveillance of PID-ARI.net is based on a 19 valent multiplex RT-PCR on naso-pharyngeal aspirates. The samples are provided by hospitals and offices in Freiburg, Mainz and Schleswig-Holstein (north, middle, south of Germany). Children with lower airway infections are prospectively enrolled. RESULTS: In the time period from July 1999 to June 2003 with 20 months of recommended palivizumab application, 5 months (25 %) would have been not on target. In two seasons the start of the vaccine campaign would have been too early (waste of two months). In one season the application would have started one month too late and in two seasons the vaccine campaign would have been stopped two months too early leaving the vaccinees on risk for acquiring RSV. CONCLUSIONS: The web-based early warning system of PID-ARI.net is the first, pathogen-specific, comprehensive and fast surveillance-system for airway pathogens in Europe. It facilitates the epidemic-synchronous use of the passive immunization with palivizumab and by this increases its efficiency and should safe costs.

Antibodies, Monoclonal↗

[Protracted croup syndrome. Bacteriologic findings and therapeutic consequences].

BACKGROUND: Croup normally is characterized by acute onset and a self limited course of only few days. In 1990 and 1991 at the University Children's Hospital Freiburg an unexpected high number of patients were hospitalized for prolonged Croup syndrome. Expanded microbiological investigations were used to uncover etiologic factors. METHODS: Of a total of 138 inpatients with Croup 60 (17 in their first year of life, 21 in the second year of life and 22 infants older than 2 years) had bacteriological (37 nasopharyngeal-, 4 tracheal-aspirates or 19 throat swabs), and virological (antigen detection in nasopharyngeal aspirates, n = 28) tests. Of these patients 48% were hospitalized longer than 3 days (mean 4,7; range 1-18 days). RESULTS: Bacteria found: B. catarrhalis 24/11 (total/pure-culture), S. pneumoniae 15/6, H. influenzae 10/3, S. group A 5/4 and S. aureus 4/1. Sixteen specimen yielded more than one pathogen, one specimen was sterile. Nasopharyngeal secretions had the most reliable results: Pure cultures (72%) and associations of two pathogens (87%) were found in these aspirates, and only 26% of the unspecific mixed findings (p < 0.005; chi 2-Test). Of the patients hospitalized longer than 3 days 27.6% had positive cultures for H. influenzae, whereas only 6.5% of those hospitalized shorter (p < 0.05; chi 2-Test). The only microorganism with an age-bound distribution was B. catarrhalis found predominantly (54.2%) in the 2nd year of life, with 62% of patients positive (p < 0.05; chi 2-Test). Virus found: RSV (n = 3), Parainfluenza 2 (1) and Parainfluenza 3 (1). CONCLUSIONS: Nasopharyngeal aspirate is the most reliable specimen for a bacteriologic diagnosis in Croup. In the second year of life B. catarrhalis is present in most Croup cases, and H. influenzae was associated with a prolonged course of the disease. An appropriate antibiotic therapy therefore must cover these two pathogens.

Antibodies, Viral↗

[Atopy-suggesting symptoms in the first 2 years of life. Effect of gestational age, nutrition and social class].

In a prospective study on 318 non-selected infants signs of atopy as well as interrelations with feeding regimens and family history of atopic disease were investigated at the age of 1 1/2 year. The study population was recruited from preterm and term babies hospitalized 1985 in the University Children's Hospital Freiburg, Germany. The most common symptom was eczema. In addition, clinical symptoms of atopy in first degree relatives were a significant risk factor. Because the highest incidence of atopic symptoms occurred in preterm born children with allergic background in their families, we therefore consider this population at highest risk to develop atopic disease. On the other hand there was no significant influence of breast feeding, cow's milk formula and the time of intake of allergenic food on the clinical manifestation of atopy in any group. Although eczema occurred predominantly in infants with higher social level the respiratory tract symptoms were reported more frequently in children from working class families. We therefore regard the social status as an important confounding variable in the studies of risk factors for the development of allergy.

Eczema↗

[Advantages of hyposensitization with a high dose of allergoid in pollen allergy].

Grass and rye pollen sensitive children were hyposensitized with glutaraldehyde-modified, tyrosine-adsorbed grass and rye allergoid. We evaluated the clinical efficacy and immunological changes associated with the administration of 3100 NOON-Units (NU) with 3 injections in 15 patients (group A) and 9100 NU with 6 injections in 13 patients (group B) preseasonally. No systemic side effects during therapy were observed. In patient's assessments, a clinical improvement was reported; however, group B achieved better symptom and medication scores. The latter group obtained slightly higher specific IgG levels than group A after two seasons of treatment, whereas the co-seasonal increase of specific IgE was higher in group A. Hyposensitization with grass and rye allergoid is a safe therapy, a better clinical and immunological effect being observed in a high dose regimen.

Child↗

The CNS symptoms of rotavirus infections under the age of two.

BACKGROUND: Since isolation of the Rotavirus (RV), there is rapidly growing concern about the possible involvement of RV in Central Nervous System (CNS) disorders, especially in Japan. We looked for symptomatic CNS involvement in a large series of RV infections and it's possible risk factors in a European setting. METHODS: Two-year retrospective survey based at the University Children's Hospital of Freiburg, Germany, a secondary and tertiary care centre with a urban and rural catchment area of 400,000 people. First, the case records of all 366 inpatients aged under two years excreting RV were searched for signs and symptoms of CNS involvement. Second, records of all 32 patients hospitalised with meningitis/encephalitis during the study period were checked for evidence of RV infection. RESULTS: In 15 of 366 children signs of CNS involvement (seizures, meningeal and encephalitic signs) were found. They were older (p = 0.023), had higher temperatures (p = 0.001) and CRP values (p = 0.019). Five of the fifteen had underlying neurological diseases, two had an additional salmonella infection and one suffered from hypernatraemic toxicosis. In the remaining seven children, higher temperature (p = 0.037) and older age (p = 0.05) remained significant risk factors. CNS-signs occurred in 2% of RV-excreting children, a rate equal to the prevalence of febrile seizures among all inpatients during the study period (2.2%). Of all 32 patients hospitalised with a diagnosis of meningitis or encephalitis only four had their stools tested for RV, all with a negative result. CONCLUSIONS: CNS symptoms in children aged less than two years with rotavirus diarrhoea have the same clinical epidemiology as febrile seizures and thus, in general, don't need additional diagnostic procedures.

Central Nervous System Infections↗

[Gamma-linolenic-acid-rich borage seed oil capsules in children with atopic dermatitis. A placebo-controlled double-blind study].

We investigated the effect of gamma-linolenic-acid from borage seed on atopic dermatitis of children. In a placebo-controlled, double-blind manner we studied 24 patients, 3-17 years old. Every patient received 360 mg of gamma-linolenic acid daily, independent from sex and age; the same amount of corn seed-oil served as placebo. After 10 to 14 weeks of treatment there was no improvement of the eczema in the verum phase compared to placebo. Both groups showed improvement while taking placebo. This result could be seen in the objective investigations (Costa-Score, 3 times per treatment period) as well as in the daily patients documentation. The patients whose eczema has improved under borage seed-oil (n = 10) had no special characteristics, so that we could not identify any responder-type.

Adolescent↗

The humoral immune response of children and infants to an RSV infection: its maturation and association with illness.

In this study the immune response of 29 newborns and infants hospitalized on behalf of a RSV infection was evaluated. Acute phase and convalescent sera were examined by a neutralization assay, in an immunoblot, and in an ELISA based on 10 synthetic peptides derived from RSV proteins. The last two tests allow to monitor the synthesis of RSV specific antibodies of the infant. Despite the presence of maternal antibodies the initial immune response seems to be random and favours linear epitopes of the protein backbone of viral proteins. The earliest protecting antibodies directed against glycosylated epitopes are acquired in the second half year of life. Antibodies generated during the primary immune response seem to predispose infected children to get ill.

Age Factors↗

Relationships between serum total iron-binding capacity and transferrin.

The relationship between serum transferrin ( TFN ) and serum total iron-binding capacity (TIBC) in a clinical setting was evaluated in two related studies. The initial study evaluated 101 blood samples representing a cross-section of hospitalized adults. The samples were double assayed for TIBC using clinical and research methodologies. TFN was assayed by a commercial radial immunodiffusion method. Clinical laboratory TIBC correlated well with research laboratory TIBC (r = 0.87, slope = 0.97, p less than 0.001, n = 50) and the relationship of TIBC to TFN yielded the following equation: TFN = 0.83 TIBC -5.6 (r = 0.82, p less than 0.001, n = 101) where TFN = mg/100 ml and TIBC = micrograms/100 ml. The second study evaluated a new TIBC assay and its effect on the TIBC/ TFN relationship. Additionally, the TFN -TIBC relationship was evaluated at low normal and abnormal TIBC levels. In this second study, TFN = 1.0 TIBC -18.8 (r = 0.88, p less than 0.01, n = 126). Subsample analysis for specimens with TIBC between 105 and 160 showed a TIBC- TFN regression line that was not significantly different than the entire sample. Inclusion of ancillary patient data such as hemoglobin and hematocrit did not improve the relationship between TFN and TIBC in either study. The relationship was unaffected by age, sex, race, disease, treatment, fever, surgery, degree of nutritional support, blood transfusion, or blood chemistry parameters in either study. Laboratories deriving TFN from measured TIBC as a nutritional status indicator must determine the relationship for the specific procedures being used in their laboratories.

Age Factors↗