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Biomedical subjects

K Tietze

Publications and source records attributed to K Tietze.

At least 19 recordsLinked to original sources

Transmission of a multiresistant Pseudomonas aeruginosa strain at a German University Hospital.

Over 15 months, 60 patients at a German University Hospital became infected or colonized by a multiresistant Pseudomonas aeruginosa strain, which was isolated from tracheal secretions, blood, urine, venous catheters, ascites and several wounds. Most patients had undergone invasive treatment (surgery, cancer therapy). The genetic relationship of the isolates was investigated by pulsed field gel electrophoresis. The isolates were resistant to beta-lactam antibiotics, including carbapenems and aztreonam, to aminoglycosides and quinolones. The only in vitro susceptibility was to polymyxin B. Extensive sampling was carried out to identify contaminated medical devices, surfaces or media (water, food). Samples were taken from doctors and nursing staff and various treatment procedures were observed for several weeks. The handling of respirators, resuscitation tubes, urine bottles, and bedpans resulted in the contamination of the patients' environment, although most devices were cleaned and disinfected with automatic washer/disinfectors. Several wash basins on the intensive care unit were contaminated, but none of the drinking water samples showed any growth of P. aeruginosa. We recommend the strict use of gloves and strict application of alcoholic hand disinfectants immediately after discarding the gloves. The chain of infection ceased after strict cohort isolation and the subsequent introduction of the specific hygiene regime.

Adult↗

Relation between maximum discharge rates on electromyography and motor unit number estimates.

To improve quantitative assessment of motor unit recruitment by standard concentric needle electromyography (CNEMG), hypothenar muscles of 22 healthy subjects, 18 with denervation, and 10 with a myopathy were studied. Discharge rates of motor units were measured in CNEMG recordings comprising action potentials of, at most, 4 motor units. Motor unit number estimation (MUNE) was done using the manual incremental method. In controls, the upper 95% limit of the discharge rate was 16.2/s. In all subjects, a strong nonlinear correlation between the number of motor units and the maximal discharge rate was found (r = 0.88, P < 0.0001). Increased discharge rates were found in all but one of the paretic muscles with denervation, but in none of the myopathic muscles. Measurement of the discharge rate is a simple and reliable procedure. If the discharge rate is high in a hypothenar muscle, loss of motor units can be inferred. Moreover, the discharge rate value gives an estimate of the number of motor units in that muscle. Thus, we suggest that maximal discharge rate be included in electromyographic reports.

Action Potentials↗

Pointed, an ETS domain transcription factor, negatively regulates the EGF receptor pathway in Drosophila oogenesis.

Spatially regulated activation of the Drosophila epidermal growth factor (EGF) receptor by its ligand, Gurken, is required for establishment of the dorsal/ventral axis of the oocyte and embryo. During mid-oogenesis, Gurken is concentrated at the dorsal-anterior of the oocyte and is thought to activate the EGF receptor pathway in adjacent follicle cells. In response to this signal, dorsal follicle cell fate is determined. These cells further differentiate into either appendage-producing or midline cells, resulting in patterning in the dorsal follicle cell layer. We show here that Pointed, an ETS transcription factor, is required in dorsal follicle cells for this patterning. Loss of pointed results in the loss of midline cells and an excess of appendage-forming cells, a phenotype associated with overactivation of the EGF receptor pathway in the dorsal region. Overexpression of pointed leads to a phenotype similar to that generated by loss of the EGF receptor pathway. This suggests that Pointed normally down-regulates EGF receptor signaling in the midline to generate patterning in the dorsal region. Interestingly, pointed expression is induced by the EGF receptor pathway. These data indicate a novel antagonistic function for Pointed in oogenesis; in response to activation of the EGF receptor, pointed is expressed and negatively regulates the EGF receptor pathway, possibly by integrating information from a second pathway.

Animals↗

Enhancer of splitD, a dominant mutation of Drosophila, and its use in the study of functional domains of a helix-loop-helix protein.

Helix-loop-helix proteins play important roles in developmental processes, such as myogenesis, neurogenesis, and sex determination. The gene Enhancer of split [E(spl)] of Drosophila, a member of a gene complex that is involved in early neurogenesis, encodes a protein with a basic domain and a helix-loop-helix motif. We took advantage of a dominant mutation of this gene, E(spl)D, to define in vivo structural features of this protein for proper function. The mutation renders the otherwise recessive eye phenotype of spl dominant. By germ-line transformation of different in vitro mutagenized versions of the E(spl) gene, we could demonstrate that the basic domain of this helix-loop-helix protein is functional and necessary for expression of the dominant phenotype. These results are supported by in vitro DNA-binding assays, which showed that the basic domain is in fact necessary for DNA binding, despite the presence of a proline residue. Furthermore, we could show that the dominant enhancement of spl is caused by truncation of the E(SPL)D protein in combination with deletion of a putative regulatory element.

Amino Acid Sequence↗

[Quantitative studies of protein and cell concentrations in the anterior chamber in cataract surgery with therapy using steroidal and non-steroidal antiphlogistic drugs].

In a prospective, randomized double-blind study, the anti-inflammatory effects of indomethacin and flurbiprofen were examined. The operation performed was extracapsular cataract extraction. For the pre- and postoperative measurement, the Laser Flare Cell Meter was used. In 76 eyes the flare and cell concentrations were measured quantitatively. It was found that, dependent on the postoperative time interval, indomethacin is more effective in reducing post-operative inflammation than flurbiprofen.

Anterior Chamber↗

Closely related transcripts encoded by the neurogenic gene complex enhancer of split of Drosophila melanogaster.

Genetic evidence suggests that E(spl), one of the neurogenic loci of Drosophila, is a gene complex comprising an as yet incompletely established number of transcription units. In order to correlate the various transcription units with E(spl) functions, wild-type flies were transformed with genomic DNA encoding the transcription unit m8 from the mutant E(spl)D, which was known to be altered in embryos carrying this mutant allele. Transformants show the same dominant enhancement of the spl phenotype as E(spl)D itself. Since m8 has a virtually identical pattern of expression as m4, m5 and m7, we have determined the sequence of these four transcripts. The deduced protein products of m5, m7 and m8 exhibit extensive sequence homology with each other. All three encode a sequence similar to one of the conserved domains of representatives of the vertebrate myc gene family which is also present in the deduced protein sequences of the Drosophila achaete-scute gene complex. Sequence analysis of the m8 transcription unit in the E(spl)D mutation revealed several DNA lesions. One of the lesions is a deletion in the region upstream of the transcription start site. Another lesion is a deletion in the coding region that leads to a shorter protein which, in addition, differs in its carboxy-terminal end from the wild-type protein by the presence of nine amino acids.

Amino Acid Sequence↗

[Social medicine in the curriculum of universities of West Germany. Recommendations for developing topics and organization].

At German universities and colleges social and community medicine is mainly taught by lecturers from various medical fields. Accordingly a great variety of topics are presented and different focuses are set. Thus orientation becomes more difficult for the students. The present paper was elaborated by experienced lecturers. It contains proposals for the organization of the lessons. With regard to the topics a list of priorities is presented and criteria for the qualification of the lecturers are formulated.

Curriculum↗

Interaction of dichloromethane and ethanol in rats: toxicokinetics and nerve conduction velocity.

The influence of a single combined administration of ethanol (174 mmol/kg per os) plus dichloromethane (1.6, 6.2, or 15.6 mmol/kg p.o.) on blood concentrations of the tested substances and of carboxyhemoglobin, and on nerve conduction velocity was studied in rats. The blood alcohol concentration was not influenced significantly by dichloromethane. The single high dose of ethanol completely inhibited the carboxyhemoglobin concentration increase due to dichloromethane, but did not prevent the dichloromethane-induced decrease of nerve conduction velocity. It produced initially lower, then higher concentrations of dichloromethane in blood than values seen after administration of dichloromethane per se. Rats treated with ethanol plus dichloromethane showed a more pronounced decrease of nerve conduction velocity compared with rats administered dichloromethane only.

Animals↗

[Animal experiments and clinical observations on poisoning with metallic mercury].

Albino rats of an own culture strain exposed to mercury were investigated electroneurographically. A disturbance of the motor nerve conduction of the ischiadic and the tibial nerve could not be established after one year. Workers exposed to mercury of two chemical plants of the district of Halle were examined neurologically and electrophysiologically. The motor nerve conduction was measured on eight peripheral nerves. The measuring values above all deviate from the normal value up to 10% more infrequently up to 20% or more.

Adult↗

[Electromyography of eye muscles in myasthenia gravis].

The importance of the combination of electromyographic examination and the Tensilon test in the diagnosis of Myasthenia gravis pseudoparalytica of the eye muscles is discussed. After intravenous injection of Tensilon in ocular myasthenia, an activity increase is found in the electromyogram, even when the motor effect on the diseased muscle is not recognisable. Myopathies and peripheral neurogenic paresis do not respond to Tensilon.

Electromyography↗

[Neuropathies following carbon monoxide poisoning].

According to the experiments carried out in animals, impairments of the peripheral nerves can, with a certain regularity, also be expected in patients in the presence of the respective high degree of carbon monoxide intoxications without clinical paralytic symptoms being detectable in every case. The changes in the motor nerve conduction velocity in our patients and in animal experiments are still found over a prolonged period of time after the acute intoxication.

Adult↗

Effect of dichloromethane on the sciatic motor conduction velocity of rats.

There is a correlation between dichloromethane dosis (X) of 1--6 mmole/kg administered i.p. to rats and the sciatic motor conduction velocity (Y): Y = 57.1--1.091 X. The correlation coefficient 'r' is 0.437 (p less than 0.01). Presumably, the decrease of nerve conduction velocity is caused by the endogenous carbon monoxide production due to dichloromethane biotransformation.

Animals↗