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Biomedical subjects

L Schrod

Publications and source records attributed to L Schrod.

33 records · Page 2Linked to original sources
PubMed1992

Polymerase chain reaction-amplification of urease genes: rapid screening for ureaplasma urealyticum infection in endotracheal aspirates of ventilated newborns.

Ureaplasma urealyticum infection has been considered to play an important role in the development of bronchopulmonary dysplasia (BPD) in premature infants. Since standard culture methods of U. urealyticum are difficult to perform, new rapid and sensitive methods are needed to detect lung infection of ventilated newborns. Here we describe the polymerase chain reaction as a rapid method to screen endotracheal aspirates for ureaplasma infection. Urease-specific sequences could only be detected in 1 out of 36 ventilated newborns. The procedure described in this paper may facilitate further studies to determine the role of U. urealyticum in development of BPD.

Bronchopulmonary Dysplasia↗
PubMed1991

Evidence for a structural mutation (347Ala to Thr) in a German family with 3-ketothiolase deficiency.

The molecular basis of 3-ketothiolase deficiency (3KTD) was examined in a 3KTD family. Immunochemical analyses showed that mitochondrial acetoacetyl-CoA thiolase (T2) biosynthesized in the patient's fibroblasts (GK06) was unstable and that the parents and brother were obligatory carriers of 3KTD. When sequencing the PCR-amplified patient's T2 cDNA, we noted a G to A replacement which caused 347Ala to Thr substitution of the mature T2 subunit. Transfection analysis revealed that this substitution resulted in an instability of the T2 protein. Analyses of the T2 cDNA and gene of the family indicated that the patient was a compound heterozygote; the allele that derived from the mother had a point mutation (347Ala to Thr) and the other allele from the father has a mutation which would abolish the T2 gene expression. This report is apparently the first definition of a mutant allele for 3KTD, at the gene level.

Acetyl-CoA C-Acyltransferase↗
PubMed1991

[Dexamethasone in the treatment of bronchopulmonary dysplasia].

Dexamethasone has been reported to benefit premature infants with bronchopulmonary dysplasia. 13 ventilator-dependent premature infants (birth weight 780-1270 g) with chronic lung disease received dexamethasone 0.5 mg/kg/day with tapering doses over 3 weeks. Dexamethasone therapy was associated with a temporary increase in urine output and blood pressure. All infants showed a significant fall in oxygen requirement and an increase of total pulmonary compliance during the first week. The endotracheal tube was successfully removed in all infants with Northway stage I/II BPD within the first week of treatment and no infant relapsed. But in Northway stage III/IV, only 2/9 infants could be weaned from the ventilator during the first course of treatment and in the majority treatment led only to a temporary improvement of pulmonary status. In parallel to the improvement of lung function we found in 7 infants a decrease of the total cell counts, the ratio PMN/macrophages and albumin in relation to urea in the bronchial lavages with a secondary rise in cases of a clinical relapse. Free elastase and fibronectin/albumin ratio in the bronchial lavage did not correlate to the clinical course. Dexamethasone seems to have not only an effect on fluid balance but also on the alveolar capillary leakage and the PMN influx into the lung. This might explain the superior effect of dexamethasone in patients with Northway stage I/II BPD in comparison to infants with Northway stage III/IV.

Bronchoalveolar Lavage Fluid↗
PubMed1991

[Functional nasopharyngeal fiberoptic endoscopy for pre-therapeutic diagnosis of sleep apnea syndrome in infants. A case report].

We report a 2-year-old infant with severe obstructive sleep apnoea. The symptoms had deteriorated for several months, and indicated complete obstruction shortly after the child fell asleep, with reduction of the oxygen saturation to under 30%. Since the obstruction could only be interrupted by waking the child, a tracheostomy was proposed. Endoscopy under general anaesthesia revealed no pathological findings. The stenosis could only be seen using transnasal fibre-optic endoscopy when the obstruction occurred during sleep: the oropharyngeal wall collapsed at the level of the velopharyngeal sphincter. A tube passed through the nose and through the collapsing section of the pharynx to the entrance of the larynx prevented the apnoea. The parents were taught to introduce and fix the tube. After an observation period of 1 year the larynx had stabilized spontaneously, and the tube has to be introduced only rarely.

Child, Preschool↗
PubMed1990

Aluminium loading in premature infants during intensive care as related to clinical aspects.

Serum concentration and urine excretion of aluminium were examined during intensive care in 26 premature infants receiving long-time parenteral nutrition. In addition, aluminium content was analysed in all fluids and medicaments used for intravenous therapy and oral feeding. Several fluids for parenteral nutrition and milk formulae were highly contaminated with aluminium, especially serum conserves, human albumin, calcium gluconicum, and special diets for enteral disorders. Small premature infants have a predisposition to aluminium loading during intensive care. In 22 premature infants serum aluminium levels exceeded 10 micrograms/L. There was a significantly negative correlation between serum aluminium levels and gestational ages. Altogether, infants with high aluminium levels showed significantly more complications, especially bronchopulmonary dysplasia, necrotizing enterocolitis, cholestasis, and osteopenia.

Aluminum↗
PubMed1988

[Intervertebral disk prolapse in childhood].

Four girls and one boy aged 11 to 16 years presented with lumbar disc disease. The main aspects of the disorder in children and its differences to adults are emphasized. The prognosis following surgical treatment is favourable.

Adolescent↗
PubMed1987

Functional analysis and quantification of the complement C3 derived anaphylatoxin C3a with a monoclonal antibody.

The C3 fragment C3a belongs to the anaphylatoxins. It has immune regulatory activity and contributes to the pathogenesis of the adult respiratory distress syndrome (ARDS). The low molecular weight (9 kD) of C3a complicates the production of antibodies to C3a. We obtained a monoclonal antibody (designated H13) to human C3a. It reacts with C3a or C3a-desArg and with native C3 but not with C5 or C5a. In immunoblot analysis it reacts with the alpha- but not with beta-chain of C3 and binds to a protein with a mol. wt of about 10 kD present in zymosan-activated sera which is only marginally detectable in nonactivated serum and absent in plasma. H13 crossreacts with the analogous proteins of rabbit, guinea pig and sheep. H13 has the capacity to bind 125I-radiolabelled C3a efficiently but fails totally to react with 125I-C5a or with other C3 alpha-chain fragments. H13 blocks C3a functional activity. It markedly inhibits C3a-induced 3H-serotonin release from platelets in vitro and similarly inhibits the C3a-induced extravasation of Evans blue into the skin in vivo. H13 does not interfere with the haemolytic activity of C3. An ELISA system was established using H13 which permits quantification of C3a in sera of polytrauma patients. The antibody H13 should facilitate further functional analysis of C3a in experimental systems. It should be useful for quantification of C3a in diagnostic assays and also for application in immunopathology.

Animals↗
PubMed1986

Characterization of a T-lymphocyte membrane protein involved in T-cell function: its contribution to T-cell recognition or cellular interaction.

A monoclonal antibody (Ab188) specific for guinea-pig T lymphocytes recognizes a membrane heterodimer protein (alpha-chain, MW 43,000; beta-chain, 39,000) and inhibits efficiently the antigen-, mitogen- or alloantigen-induced T-cell proliferation. The role of this protein in T-cell activation was analysed in more detail with emphasis on the recognition or activation event of T cells. Quin 2, an intracellularly trapped calcium indicator, was used to measure calcium influx into T cells. The addition of the mitogen concanavalin A to T cells loaded previously with quin 2 induced an increase in fluorescence, revealing an increase in intracellular free calcium. This calcium increase is considered as one of the primary events in the initiation of T-cell activation and was blocked by Ab188. In contrast, other T-cell specific antibodies that react to a comparable extent with T cells had no effect on calcium increase. This indicates that Ab188 is directed to a protein involved in a very early step of T-cell activation. Alloreactive T-cell lines were established from a secondary mixed leucocyte culture by soft agar cloning. Single T-cell colonies were picked and were propagated by repeated restimulation with allogeneic macrophages differing in MHC-class II antigens. In a chromium release assay, the cytotoxic activity of several strain 13 T-cell lines directed against strain 2 Ia antigens was inhibited by Ab188 to about 50%. Similarly, Ab188 inhibited the cytotoxic activity of a MHC-class I-restricted TNP-specific T-cell line of strain 2 guinea-pigs to about 50%. In contrast, lectin-mediated cytotoxicity of the T-cell lines against murine P815 mastocytoma target cells remained unaffected. These results indicate that Ab188 interferes with the function of a protein contributing to the recognition event in the process of T-cell activation.

Animals↗
PubMed1985

Expression of polypeptide segments of the human complement component C3 in E. coli: genetic and immunological characterization of cDNA clones specific for the alpha-chain of C3.

The third component of complement C3 and its fragments have a central role in a variety of host defense mechanisms. The identification of functionally relevant C3 domains is important because of the marked functional versatility of the C3 molecule. Several human C3 cDNA clones from a human liver cDNA library were isolated and characterized. A bacterial expression vector system was used to express cDNA clones that were identified by an immunological screening procedure. The C3 cDNA clones produced in E. coli the hybrid proteins consisting of cro-beta-galactosidase and polypeptide segments of human C3, as revealed by Western blotting with antisera to human C3. The C3 moiety of the hybrid proteins had a m.w. of up to 46.000. Polyclonal antibodies against the C3 segments expressed by one of the C3 cDNA clones (ReC3-1) have been raised in mice and rabbit, and in addition, a monoclonal antibody was produced. The antisera and the monoclonal antibody reacted in Western blotting analysis selectively with the alpha-chain, but not the beta-chain of human C3. Restriction mapping of the different cDNA clones was performed, and revealed that the different clones were partially overlapping. The ReC3-1 cDNA clone included a 0.7 kb noncoding region at the 3' terminal end of the C3 cDNA. One of the restriction sites (Hind III) identified in the ReC3-1 cDNA clone was not present in the recently published sequence of human C3 cDNA. This difference in nucleotide sequence provides direct evidence for C3 polymorphism at the DNA level. The combination of immunologic procedures with recombinant DNA methodology should facilitate additional analysis of the structure-function relationship of the C3 molecule.

Animals↗
PubMedDate not supplied

Possible reasons for failure of conventional tests for diagnosis of fatal congenital toxoplasmosis: report of a case diagnosed by PCR and immunoblot.

Diagnosis of subclinical congenital toxoplasmosis has to rely on serological methods or isolation of the parasite. We present a case of congenital toxoplasmosis, in which conventional tests failed to establish the diagnosis. It was shown that this infant developed an intrathecal antibody response that was directed only against one of two Toxoplasma gondii strains used for routine diagnosis. In contrast to conventional tests, the diagnosis of cerebral toxoplasmosis could be established by using immunoblot and polymerase chain reaction (PCR). We therefore suggest that in unclarified cases, PCR and immunoblot, using at least two different strains of T. gondii, should be considered as additional tools for diagnosis of an infection with Toxoplasma and that examination of cerebrospinal fluid may be critical.

Adult↗
PubMedDate not supplied

[Effects of prepartum infusion solutions on glucose and bilirubin metabolism of mother and child in the prepartum and postpartum period].

BACKGROUND: Administration of glucose 5% infusion is regularly used in obstetrics. The purpose of the study was to investigate the effects of glucose as compared to xylose and electrolyte solutions on parameters of maternal and fetal glucose and bilirubin metabolism during labour and after delivery. PATIENTS AND METHODS: 53 pregnant women (> or = 37 weeks of gestation, uncomplicated pregnancies) were randomised by entering the delivery ward. Under labour either glucose 5%, xylose 5% or electrolyte infusions were administered. Maternal serum glucose, serum osmolarity, insulin and glucagon were analysed before administration and 20 minutes after delivery. In the newborn blood osmolarity and serum glucose levels were analysed in the umbilical cord directly after birth and in capillary blood samplings 2 hours after birth. RESULTS: Maternal blood glucose levels 20 min. post partum were significantly different (p < 0.05). Maternal insulin and glucagon concentrations 20 min. pp showed similar trends with glucose levels but were not significantly different. Glucose levels in the umbilical cord were significantly higher in the glucose than in the electrolyte group, but not higher than in the Xylit group. In contrast, the glucose-levels in the newborns after 2 h were significantly higher in the glucose group compared with both other groups. No significant differences were observed in bilirubin levels. Osmolarity in the umbilical cord between groups differed significantly. CONCLUSIONS AND DISCUSSION: In conclusion, the administration of different solutions showed a distinct influence on the maternal and neonatal glucose metabolism. A significant impact on the bilirubin levels could not be shown in this study.

Adult↗
PubMedDate not supplied

[Congenital Hyposplenia with multiple additional anomalies: a variant of the Ivemark Syndrome].

We report an 18-months-old boy with congenital spleen hypoplasia and cardiovascular defects. Besides, several minor clinical manifestations such as facial anomalies, hypospadia glans penis, agenesis of the corpus callosum and iris anomalies were observed. A partial or complete lateralisation defect could be excluded. The patient's phenotype comprises a previously undescribed combination of major and minor clinical features of the Ivemark syndrome. The case indicates that a common genetic defect might be the cause of this syndrome, which shows a variable expression.

Abnormalities, Multiple↗
PubMedDate not supplied

[Effect of body position and positioning changes on lung function of ventilated premature and newborn infants].

We studied 21 intubated premature infants (wts 800-2800 g) with respiratory distress syndrome between day 2 and 10 to evaluate the effect of body position on lung mechanics and gas exchange. The dynamic compliance of the total respiratory system was similar in the prone and supine position. When the infant was turned from the supine or the prone position to the other one, a significant improvement of oxygenation was seen temporarily. Positioning did not significantly affect the dynamic compliance, the minute volume or pCO2. In circulatory stable premature infants a change of the body position probably alters the regional ventilation to perfusion ratio and leads to a reduction of intrapulmonary venous admixture.

Carbon Dioxide↗
PubMedDate not supplied

[Antepartum prevention and postnatal therapy of respiratory distress syndrome].

The introduction of surfactant in the therapy of respiratory distress syndrome (RDS) reduced mortality and long term complications in very premature infants. Nevertheless, the obstetric management influences critically the outcome. In a prospective study of 116 premature infants with RDS treated with natural surfactant preparations after birth, mortality was significantly reduced by antepartum corticosteroid therapy suggesting a synergistic effect of corticosteroids and surfactant on the immature lung. It is assumed that a preventive administration of surfactant immediately after birth would benefit neonates at risk for RDS more than a delayed surfactant replacement after the development of RDS. But without a reliable assessment of fetal lung maturity before birth more than 50% of our premature infants with birth weights less than 1500 g would be exposed to surfactant unnecessarily. It is important that fetal asphyxia is avoided. Acquired respiratory distress syndrome occur even in premature infants after shock or meconium aspiration and may respond poorly to surfactant replacement. This is also the case in lung hypoplasia or perinatal infection, where the combined efforts of obstetricians and neonatologists are needed to attain better results.

Adrenal Cortex Hormones↗