[Management of the cut-out of various forms of osteosynthesis for proximal femoral fractures]. / Management des Cut-out verschiedener Osteosyntheseformen bei proximalen Femurfrakturen.

Proximal femoral fractures are a common type of injury in older people. A cut-out of the femoral neck screw after initial osteosynthetic surgery of proximal femoral fractures is a frequent and feared complication. There could be different causes for cut-outs. Osteoporosis and necrosis of the femoral head could be biological reasons for cut-outs; however, mechanical factors, such as reduction, implant position and morphological characteristics of fractures also have a major influence on the cut-out rate. The treatment of the cut-out is often complex and depends on the destruction of the femoral head and the acetabulum. If the bone quality is still good and the head is not completely destroyed, a reosteosynthesis can be performed. Conversion to an endoprosthetic replacement is often the only possibility. Endoprosthetic treatment is often complex and associated with a high morbidity.

Unique phylogenetic relationships of glucokinase and glucosephosphate isomerase of the amitochondriate eukaryotes Giardia intestinalis, Spironucleus barkhanus and Trichomonas vaginalis.

Glucokinase (GK) and glucosephosphate isomerase (GPI), the first two enzymes of the glycolytic pathway of the diplomonads Giardia intestinalis and Spironucleus barkhanus, Type I amitochondriate eukaryotes, were sequenced. GPI of the parabasalid Trichomonas vaginalis was also sequenced. The diplomonad GKs belong to a family of specific GKs present in cyanobacteria, in some proteobacteria and also in T. vaginalis, a Type II amitochondriate protist. These enzymes are not part of the hexokinase family, which is broadly distributed among eukaryotes, including the Type I amitochondriate parasite Entamoeba histolytica. G. intestinalis GK expressed in Escherichia coli was specific for glucose and glucosamine, as are its eubacterial homologs. The sequence of diplomonad and trichomonad GPIs formed a monophyletic group more closely related to cyanobacterial and chloroplast sequences than to cytosolic GPIs of other eukaryotes and prokaryotes. The findings show that certain enzymes of the energy metabolism of these amitochondriate protists originated from sources different than those of other eukaryotes. The observation that the two diplomonads and T. vaginalis share the same unusual GK and GPI is consistent with gene trees that suggest a close relationship between diplomonads and parabasalids. The intriguing relationships of these enzymes to cyanobacterial (and chloroplast) enzymes might reflect horizontal gene transfer between the common ancestor of the diplomonad and parabasalid lineages and the ancestor of cyanobacteria.

An overview of endosymbiotic models for the origins of eukaryotes, their ATP-producing organelles (mitochondria and hydrogenosomes), and their heterotrophic lifestyle.

The evolutionary processes underlying the differentness of prokaryotic and eukaryotic cells and the origin of the latter's organelles are still poorly understood. For about 100 years, the principle of endosymbiosis has figured into thoughts as to how these processes might have occurred. A number of models that have been discussed in the literature and that are designed to explain this difference are summarized. The evolutionary histories of the enzymes of anaerobic energy metabolism (oxygen-independent ATP synthesis) in the three basic types of heterotrophic eukaryotes those that lack organelles of ATP synthesis, those that possess mitochondria and those that possess hydrogenosomes--play an important role in this issue. Traditional endosymbiotic models generally do not address the origin of the heterotrophic lifestyle and anaerobic energy metabolism in eukaryotes. Rather they take it as a given, a direct inheritance from the host that acquired mitochondria. Traditional models are contrasted to an alternative endosymbiotic model (the hydrogen hypothesis), which addresses the origin of heterotrophy and the origin of compartmentalized energy metabolism in eukaryotes.

Epitope tagging permits cell surface detection of functional CFTR.

The cystic fibrosis transmembrane conductance regulator (CFTR) is a phosphorylation-activated Cl channel responsible for adenosine 3',5'-cyclic monophosphate (cAMP)-induced Cl secretion across the apical membranes of epithelial cells. To optimize its detection for membrane localization studies, we tagged CFTR with epitope sequences at the carboxy terminus or in the fourth external loop. When epitopes were added to the fourth external loop, the N-linked glycosylation sites in that loop were either preserved or they were mutated to produce a deglycosylated CFTR (dgCFTR). Tagged CFTRs were expressed in HeLa cells, and their cAMP-sensitive Cl permeability was assayed using the halide-sensitive fluorophore SPQ. CFTRs containing the M2 epitope showed halide permeability responses to cAMP, whereas cells expressing CFTR with the hemagglutinin (HA) tag showed little or no cAMP response. Xenopus oocytes expressing dgCFTR, with or without the M2 epitope, showed Cl conductance responses that were 20% of the wild-type response, whereas M2-tagged constructs retaining the glycosylation sites responded like wild-type CFTR. External M2-tagged CFTR was detected in the surface membrane of nonpermeabilized cells. The surface expression of the mutant M2-tagged CFTRs correlated with processing of these mutants (Gregory et al. Mol. Cell. Biol. 11:3886-3893, 1991). M2-901/CFTR is a useful reporter for the trafficking of wild-type and mutant CFTRs to the cell surface.

Expression of an abundant alternatively spliced form of the cystic fibrosis transmembrane conductance regulator (CFTR) gene is not associated with a cAMP-activated chloride conductance.

The cystic fibrosis transmembrane conductance regulator (CFTR) gene encodes a cAMP-activated chloride (Cl-) channel, and expression of the full length gene in vitro is sufficient to correct the Cl- conductance defect that is characteristic of cystic fibrosis (CF) epithelial cells. Alternatively spliced forms of CFTR mRNA have been identified in several tissues from normal individuals. One of the alternative transcripts, often present at high levels, results in the in-frame deletion of exon 9. Translation of this transcript would result in a CFTR protein missing the amino terminal portion of the first nucleotide binding fold (NBF). To evaluate the possible function of this form of CFTR, a cDNA representing this transcript (CFTR delta 9) was transduced into CFPAC cells, which are derived from a CF patient. CFTR delta 9 RNA was expressed in the transduced cell lines, but only immature, incompletely glycosylated protein was detectable by Western blot analysis. No increase in cAMP-activated anion permeability was detectable by 125I efflux assay or by means of the halide sensitive dye 6-methoxy-N-(3-sulfopropyl) quinolinium (SPQ). In a second assay system, in vitro synthesized mRNA representing CFTR delta D9 was injected into Xenopus oocytes, but expression of this alternatively spliced form of CFTR was not associated with the appearance of Cl- conductance. These results suggest that the protein produced by the CFTR delta 9 transcript is not properly processed and is not capable of generating Cl- conductance in response to cAMP. Whether this alternative transcript has some other function or represents 'noise' in the mRNA splicing mechanism remains unresolved.

[Lysosomal enzyme activity of monocytes/macrophages following incubation with postprandial hyperlipemic serum and its significance for the development of atherosclerosis]. / Lysosomale Enzymaktivität von Monozyten/Makrophagen nach Inkubation mit postprandialem fettreichem Serum und ihre Bedeutung in der Entstehung der Atherosklerose.

Lipid accumulation in macrophages is a prominent feature of the atherosclerotic lesion. Decreased lysosomal function of these cells might play an important role in the pathogenesis of the atherosclerotic foam cell. In this investigation six normal volunteers were fed a meal with a high fat content (68.9% energy, P/S ratio 0.13). The hyperlipidemic postprandial serum was incubated with monocyte derived macrophages. The enzyme activity of cathepsin B, acid cholesterylester-hydrolase and N-acetyl-beta-hydrolase decreased significantly in these cells. Thus, inadequate response in enzyme activity of lysosomal enzymes in case of fat overload might contribute to the development of the atherosclerotic foam cell.

[Neurofibromatosis and the development of neurofibrosarcoma simulating Baker's cyst]. / Neurofibromatose und Entwicklung eines Neurofibrosarkoms unter dem klinischen Bild einer Baker-Zyste.

A 39-year-old female patient with familiar neurofibromatosis developed a sarcoma in the hollow of the knee that appeared clinically and sonographically as a Baker cyst. Following an operation to remove the tumour and subsequent local radiation treatment multiple metastases appeared distant to the primary tumour from which the patient died. On the observation of a Baker cyst in a patient with neurofibromatosis the possibility of malignant degeneration must be kept in mind and an operation carried out immediately.

Relapsing acute febrile neutrophilic dermatosis and essential thrombocythemia.

Relapsing acute febrile neutrophilic dermatosis ( AFND ) is reported in a patient with essential thrombocythemia representing the first case of this kind described in the literature. The patient presented with fever, malaise, neutrophilic leukocytosis, dysproteinemia, and coalescing bluish-red painful plaques and papules at palms, forehead, lid, forearm, and thigh. There was a dramatic response to steroids, or indomethacin, with no scarring. AFND was preceded by sore throat and an upper respiratory infection and was accompanied by conjunctivitis and arthritis of knees and ankle-joint. The association of AFND with essential thrombocythemia and with other neoplastic disorders is discussed.

[Wegener's granulomatosis: an example for the collaboration between the specialist for otorhinolaryngology and internal medicine (author's transl)]. / Die Wegenersche Granulomatose, ein Beispiel für die Zusammenarbeit zwischen Arzt für HNO-Krankheiten und Internist.

Diagnosis, treatment and follow-up of patients with Wegener's Granulomatosis is described as an example for the collaboration between the specialist for otorhinolaryngology and internal medicine. In all cases reported a muco-sanguinous rhinitis was the first manifestation of the disease. All patients presented lung involvement while the kidneys were involved in 75%. As histologic examination does not always give a pathognomonic feature, diagnosis has to be made relying on clinical data and natural course of the disease. Cyclophosphamide in combination with corticosteroids is the treatment of choice. This treatment has considerably improved the previously unfavorable prognosis of this disease. A long term follow-up of patients with Wegener's Granulomatosis by specialists for otorhinolaryngology and internal medicine seems to be absolutely necessary.