[Posttraumatic complications after pediatric ankle injuries]. / Posttraumatische Komplikationen am kindlichen Sprunggelenk.

Ankle sprains are common injuries in childhood and are generally harmless. However, fractures of the ankle joint are rare, but complications (persistent rotational or axial deformity, alteration of growth of the distal tibia or fibula, or joint deformity) can lead to serious problems during growth. The clinical relevance of growth disturbances at the distal tibia or fibula depends on the age at the time of fracture more than on the fracture type, severity of dislocation, or interponated material in the fracture gap. Both stimulation and inhibition of growth are possible. Inhibition of growth at the distal tibial growth plate regularly leads to varus deformity and shortening. This is of clinical importance as this type of growth disturbance is the most common. Valgus deformity is rare, mostly due to persistent axial deviation of an insufficiently reduced fracture. Transitional fractures always occur at the time of growth plate closure; thus, growth disturbances do not play a role. Transitional fractures could be overlooked or treated insufficiently, leading to a step or gap of the joint surface.

Mammalian glial cells in culture synthesize acetylcholine.

In the present study we demonstrate that acetylcholine is synthesized by cultured mammalian glial cells identified by cell-type specific markers. Primary cultures of rat brain astrocytes or microglia contained 2.0 and 1.6 pmol acetylcholine/10(6) cells on average respectively. Astrocyte cultures established from neonatal mouse brain contained even more acetylcholine (about 80 pmol acetylcholine/10(6) cells). Primary cultures of rat brain astrocytes showed choline acetyltransferase (ChAT) enzyme activity of 3 nmol/mg protein/h; ChAT activity was blocked by 10 microM bromoacetylcholine. In conclusion, these data demonstrate the synthesis of the "neurotransmitter" acetylcholine in cultured glial cells, a finding which opens a new view upon the role of acetylcholine in mammalian brain.

Pramipexole binding and activation of cloned and expressed dopamine D2, D3 and D4 receptors.

Pramipexole (SND 919; 2-amino-4,5,6,7-tetrahydro-6-propylamino-benzthiazole-dihydrochlor ide) is a potent dopamine autoreceptor agonist. We have carried out an analysis of the binding affinities of dopamine D2L, D2S, D3, and D4 receptors for pramipexole using both [3H]pramipexole and [3H]spiperone as radioligands at cloned and heterologously expressed receptors. Studies were carried out using rat and human D2L, D2S and D3 receptors with equivalent results. When the binding of pramipexole to the high affinity, guanine nucleotide-sensitive state of each receptor was analyzed, pramipexole is most selective for D3 compared to D2 and D4 receptors. These results indicate a 5-fold selectivity of pramipexole for D3 receptors, while quinpirole and bromocriptine are non-selective or more D2/D4 receptor selective. Two measurements of receptor activation for dopamine D2, D3, and D4 receptors also show that pramipexole is most potent for activation of D3 receptors. The dopamine D3 receptor selectivity of pramipexole may explain the previously described properties of this drug, including its potent autoreceptor preference.

Comparison of the carbohydrate moieties of recombinant soluble Fc epsilon receptor (sFc epsilon RII/sCD23) expressed in Saccharomyces cerevisiae and Chinese hamster ovary cells. Different O-glycosylation sites are used by yeast and mammalian cells.

Recombinant human soluble low affinity receptor for the Fc portion of IgE (sFc epsilon RII/sCD23) was produced in Saccharomyces cerevisiae or Chinese hamster ovary cells and subjected to carbohydrate analysis. Applied methods included analytical SDS-PAGE, reversed phase HPLC, methylation analysis and sequential degradation with exoglycosidases. The results revealed that sFc epsilon RII derived from Chinese hamster ovary cells is glycosylated exclusively at Ser-147, containing mainly the trisaccharide Sia(alpha 2-3)Gal(beta 1-3)GalNAc, whereas the yeast derived glycoprotein was glycosylated at Ser-167 and contained only alpha-mannosyl residues. It is shown here for the first time that different amino acids of a given protein can be O-glycosylated when expressed in yeast or Chinese hamster ovary cells.

Recombinant soluble Fc epsilon receptor II (Fc epsilon RII/CD23) has IgE binding activity but no B cell growth promoting activity.

We have undertaken the production of recombinant soluble Fc epsilon receptor II (Fc epsilon RII) as a secretory protein, but not as a cleavage product of membrane-bound receptor. Several plasmid constructs containing soluble receptor sequence were prepared. Only a chimeric gene containing the sequences encoding IL-6 signal peptide and the soluble moiety of Fc epsilon RII could be expressed in Xenopus laevis oocytes and CHO cells, resulting in the secretion of soluble Fc epsilon RII. The recombinant soluble Fc epsilon RII was also produced in the yeast expression system. The NH2-terminal sequence analysis of the chimeric gene product generated by oocytes demonstrated the correct cleavage of IL-6 leader sequence by a signal peptidase. Moreover, most of CHO cell and all of the yeast-derived recombinant molecules were products identical with the native B cell-derived soluble Fc epsilon RII. These recombinant products as well as the natural soluble receptor derived from a human B cell line could bind both human IgE and two different anti-Fc epsilon RII mAb and could competitively inhibit the binding of IgE to Fc epsilon RII-expressing cells. However, the recombinant soluble Fc epsilon RII and highly purified native molecules did not display any B cell growth-promoting activity.

Synthesis and expression of MHC class II molecules in the absence of attached invariant chains by recombinant-interferon-gamma-activated bone-marrow-derived macrophages.

Pure populations of in vitro propagated bone marrow-derived macrophages are constitutively Ia negative. Co-culturing of these cells with recombinant interferon-gamma (rIFN-gamma) resulted in the appearance of high amounts of Ia antigens at the cell surface of essentially all cells. The continuous presence of the stimulus was a prerequisite for sustained Ia expression because removal of the stimulus resulted in rapid decline of surface Ia. Two-dimensional (2D) gel analysis (1D isoelectric focusing, 2D sodium dodecyl sulfate-polyacrylamide gel electrophoresis) of class II molecules synthesized by rIFN-gamma-stimulated bone marrow macrophages (BMM phi) revealed that, in contrast to class II complexes hitherto described, BMM phi-derived I-A and I-E subregion-encoded subunits are synthesized without invariant chains. The invariant chain-deficient alpha,beta heterodimers are expressed at the cell surface in high proportions demonstrating that their correct assembly and transport to the cell surface is accomplished in the absence of invariant chains. The lack of invariant chains appears not to be due to a failure of rIFN-gamma to induce transcription of the gamma-chain gene because rIFN-gamma-induced, in contrast to uninduced, BMM phi accumulate high levels of invariant chain-specific transcripts as evidenced by Northern blot analysis. These findings suggest that translation of gamma-chain-specific mRNA is blocked in BMM phi for as yet unknown reasons. Alternatively, newly synthesized gamma chains might have escaped their regular intracellular maturation pathway as a result of unidentified modifications mediated by altered post-translational processing mechanisms.

Biochemical aspects of constitutive and facultative expression of MHC class II molecules at the pre- and posttranslational level.

Biosynthetic properties of Ia antigens derived from B cells, from T cell clone BK-BI-2.6.C6 and from rIFN-gamma induced bone marrow macrophages (BMMO) were evaluated before and after translation. Gross features of B and T cell Ia were found to be very similar. At the pretranslational level no obvious differences were noticed. Following translation in both cases alpha, beta heterodimers associate noncovalently with invariant proteins of the gamma-chain group. These proteins, in particular the principal gamma-chain (p32) become the target of extensive posttranslational modification by sialic acid. The effect is much more pronounced in T cells than in B cells. Unlike in B cells, at the cell surface the bulk of terminally glycosylated gamma-chain (p35) remains attached to the alpha, beta isotypic complexes. This finding renders such T cells very useful for studies on the possible role of the invariant chain during antigen presentation. In BMMO rIFN-gamma elicited high levels of transcripts of polymorphic alpha, beta and invariant gamma chains. However, translation of the polymorphic subunits and their expression at the cell surface occurred in substantial amounts in the total absence of invariant chains. This finding argues against the notion of gamma being required for assembly of alpha, beta isotypes and their intracellular transport to and expression at the plasma membrane.

[The interferon system. A review of biological principles and clinical uses]. / Das Interferon-System. Eine Ubersicht über biologische Grundlagen und klinische Anwendungen.

Interferons are endogenous proteins produced by vertebrates in response to viral infections and is immunoregulatory agents. Three types of interferon are known today: IFN-alpha, IFN-beta und IFN-gamma which show different degree of relationship to each other in molecular structure and activity. Several interferons are produced in large amount by recombinant DNA technology. Their most important properties are their antiviral activity, their antiproliferative and immunoregulatory activities. Clinical trials showed that interferons can be used as therapeutic agents in viral infections and malignant diseases. Results of treatment in certain viral infections or virally induced tumors and some particular haematologic malignancies are very good. Many frequent forms of tumors still respond less or not at all to interferon treatment. Interferons have many different effects in vivo and can act synergistically with other agents. Further success in cancer therapy can therefore be expected from investigations on optimum dose schedule and effective combination regimes.

[Effects of classes in "creative movement and pantomime" and "badminton" on total-body coordination in older dyslexic boys]. / Die Auswirkungen einer Unterrichtseinheit "Schöpferische Bewegung und Pantomime" und einer Unterrichtseinheit "Badminton" auf die Gesamt-körperkoordination älterer legasthener Jungen.

Reported previously from a U.S. empirical study of 7th grade high-school students (102 male and 84 female) where statistically significant results had been found relative to total body coordination and body image (Schneider, 1978), the effectiveness of a series of classes in "creative movement and pantomime" was verified in a 7.5-week longitudinal study of 7th grade male students (N = 20) attending remedial education at a special school for dyslexic students in Massachusetts, U.S.A. It has been possible to demonstrate that these classes had achieved statistically significant improvements in overall body coordination of Ss, measured with the body coordination test KTK - Körper-Koordinationstest für Kinder (Schilling, Kiphart, 1974). Findings obtained from the control group (N = 20) who, during that same period, had been taught, and practising, "Badminton" in the regular sports classes, elicited the same specific, statistically significant gains in overall body coordination. These improvements are considered attributable to the additional, specific stimuli for development provided to the dyslexic students by "creative movement and pantomime" classes and the racket sport "Badminton" alike. The findings support the thesis that delayed formation of hemispheric linkage is present in dyslexic persons, and that specific movement programmes provide developmental stimuli that influence overall body coordination.

[The value of suprapubic bladder aspiration in the diagnosis of bacteriuria (author's transl)]. / Zur Bedeutung der Blasenpunktion für den sicheren Nachweis einer Bakteriurie

Urine obtained simultaneously by midstream voiding and supra-public bladder aspiration from 500 patients were compared by bacteriological and, in some, microscopic examination. In a second series a similar examination was undertaken on 1000 samples each, obtained by midstream voiding, catheterisation or suprapublic bladder aspiration from different patients. There was no significant difference in sediments or Stansfeld count between midstream and aspirated samples. Qualitative false-positive results for protein were obtained in 20% of midstream samples from women. The Kass count for significant bacteriuria was false-positive in 3.4% of midstream compared with bladder-aspiration samples, in 7.6% for "questionable bacteriuria". Positive counts of under 10(5)/ml were obtained in 41.3%, of under 10(4)/ml in 26.7% of aspirated samples. Counts under 10(4)/ml in midstream-voided samples are usually considered the result of contamination, at times falsely so. "Mixed infections" were 7.8 times more common in catheter and 11.4 to 11.8 times more common in midstream than in aspirated samples. The presence of microorganisms in suprapublic bladder aspiration is always abnormal. Chemotherapy is indicated only on results from bladder aspiration.