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Biomedical subjects

M Reuter

Publications and source records attributed to M Reuter.

At least 181 records · Page 10Linked to original sources
PubMed1990

Immunocytochemical localization of histamine in flatworms.

Specific antibodies against histamine were used to demonstrate the occurrence and cellular distribution of histamine-like immunoreactivity in three species of flatworms (phylum Platyhelminthes). In the parasitic cestode Diphyllobothrium dendriticum, histamine-reactivity was found in neurons of the main nerve cords, and in cells lining the central and peripheral excretory ducts. In the free-living microturbellarian Microstomum lineare and in the planarian Polycelis nigra, histamine-immunoreactivity was restricted to cells and fibres of the nervous system. The occurrence of histamine or a related substance in the nervous system of flatworms, which represent primary bilateria, indicates the importance of this neuroactive substance in the animal kingdom.

Animals↗
PubMed1989

Oligonucleotide duplexes containing CC(A/T)GG stimulate cleavage of refractory DNA by restriction endonuclease EcoRII.

Some DNA species are resistant towards the restriction endonuclease EcoRII despite the presence of unmodified recognition sites. We show that 14 base-pair oligonucleotide duplexes containing the EcoRII recognition site 5'-CC(A/T)GG are cleaved by this enzyme and are able to stimulate EcoRII cleavage of such resistant DNA molecules (e.g. DNA of bacterial virus T3). A direct correlation between the concentration of oligonucleotide duplex molecules and the degree of EcoRII digestion of the primarily resistant DNA is observed. This indicates a stoichiometric rather than a catalytic mode of enzyme activation. An excess of DNA devoid of EcoRII sites ('non-site' DNA, e.g. MvaI-digested T7 DNA) does not interfere with the activity of EcoRII.

Base Sequence↗
PubMed1989

Development and differentiation of neuronal subsets in asexually reproducing Microstomum lineare. Immunocytochemistry of 5-HT, RF-amide and SCPB.

The development of immunoreactivity (IR) in the nervous system of asexually reproducing Microstomum lineare has been studied by a combination of simultaneous and double immunostaining with antisera to 5-HT and RF-amide, as well as with monoclonal antibodies to SCPB (molluscan small cardioactive peptide). Immunoreactivity appears in a distinct sequential order. 5-HT antigenicity in the postpharyngeal commissure indicates the initiation of the development of a new zooid. The development of a new brain and pharyngeal plexus always starts in connection to the parental nerve cords. Significantly different developmental patterns are observed for the IR to 5-HT and RF-amide, whereas IR to SCPB has the same localization as that to RF-amide, but appears both weaker and later during the development. Influences of the immunoreactive substances on the asexual reproduction and the feeding behaviour are discussed.

Animals↗
PubMed1989

[Current indications for angiography of tumors of the muscular and skeletal systems].

CT and MRI have greatly influenced the indications for angiography as a diagnostic method for tumours of the muscular and skeletal systems. 59 patients with bone and soft tissue tumours were examined by arteriography (DSA) and the indications for arteriography were compared with CT (32 cases) and MRI (15 cases). Particular attention was paid to the presence of vessel encasement. Arteriography is the definitive method for demonstrating vascular involvement. Tomographic methods demonstrate the topographic relationships of the tumour and neuro-vascular structures. Angiography can also be used as an interventional measure pre-operatively or for palliative embolisation.

Adolescent↗
PubMed1989

"Neuroendocrine cells" in flatworms--progenitors to metazoan neurons?

The integrative mechanisms in phylum Platyhelminthes are of considerable phylogenetic interest since ancestral flatworms are believed to be progenitors to all "higher" metazoans. The phylum consists of free-living and parasitic worms. In this group of early bilateral animals, the nervous system is condensed and consists of a bilobed brain and longitudinal nerve cords. Endocrine glands and a circulatory system are still lacking. The present review deals mainly with microturbellarians and parasitic worms. Three main types of neurons, all containing vesicles, occur in the worms: neurons containing dense-core vesicles, peptidergic neurons and sensory neurons. All types of neurons react positively to antisera towards invertebrate and vertebrate neuropeptides. Neurons containing dense-core vesicles are the most frequent type. The dense-core vesicles occur both in the cell soma and in their long processes. Neurons of this type form synaptocrine and paracrine release sites. We ask: Is the neuron containing dcv an archaic type of neuron in which the characteristics of the stem cells for neurons have been preserved?

Animals↗
PubMed1988

EcoRII can be activated to cleave refractory DNA recognition sites.

EcoRII restriction sites [5'-CC(A/T)GG] in phage T3 and T7 DNA are refractory to cleavage by EcoRII, but become sensitive to cleavage in the presence of DNAs which contain an abundance of EcoRII sensitive sites (e.g. pBR322 or lambda DNA). Studies using fragments of pBR322 containing different numbers of EcoRII sites show that the susceptibility to EcoRII cleavage is proportional to the number of sites in the individual fragment. We postulate that EcoRII is the prototype of restriction endonucleases which require at least 2 simultaneously bound substrate sites for their activation. EcoRII sites are refractory when they occur at relatively low frequency in the DNA. The restriction enzyme can be activated by DNA with a higher frequency of sites.

DNA Restriction Enzymes↗
PubMed1988

[Computed tomography of bronchiectasis].

Twenty-six patients with suspected bronchiectasis were examined by bronchography and CT and the CT appearances of normal and abnormal bronchi are described. Like bronchography, CT will distinguish between cylindrical and cystic bronchiectasis. Lobar and segmental localisation can be reliably achieved by both methods; there was agreement between these methods in 109 out of 114 lobes and in 391 out 468 segments. In our experience the sensitivity of CT in the diagnosis of bronchiectasis is 93% and specificity is 96%. It is possible to obtain the necessary information, i.e. the existence and localisation of bronchiectasis by means of CT.

Adult↗
PubMed1988

[Image intensifying split radiography].

This is a report on the testing of a novel system of radiography of the thorax consisting of a combination of moving-slit radiography with a slot-type image intensifier (proximity focussed linear image intensifier), being thus a variant of rotational scanography (or a swinging slot x-ray machine), the image scale being 1:1. The system was compared with conventional x-ray film/foil technique using a group of 115 patients. Special features of the new system are a very low irradiation exposure dose and a 100 x 100 mm size image. It is shown that the imaging method is highly efficient in respect of the examined nine classes of findings and that the image quality of large-size thorax x-ray films is very nearly attained. The low exposure dose, low running cost and advantages in storing and indexing can serve as counter-arguments against the well-known reserved attitude in respect of a medium-size format. The system opens good future possibilities especially with regard to follow-up and monitoring of selected patient groups (e.g. blood donors, medical personnel).

Heart Diseases↗
PubMed1987

[Host-dependent modifications of bacteriophage T3 expressing changes in adsorption properties (serological study)].

The ability of the bacteriophage T3 to adsorb on the host cells of Escherichia coli W1655 changes depending on the host strain in which the phage was propagated before. This phenomenon is termed "non-classical" host-controlled modification in contrast to "classical" DNA modification. We demonstrate here that T3 phages with various non-classical modifications as well as the host range mutant T3hW differ from each other in the antigenic determinants of the phage adsorption protein.

Adsorption↗
PubMed1987

[Roentgenologic diagnosis and differential diagnosis of carcinomatous lymphangiosis of the lungs].

Generalised lymphatic carcinosis, also known as lymphangitis carcinomatosa, cannot be diagnosed by just one x-ray film of the thoracic organs. However, if an enhanced reticular striated pattern is seen, possibly associated with miliar stippling or hilar masses it is recommended to perform short-term follow-ups and comparisons with previous x-ray films. Lymphangitis carcinomatosa becomes probable if rapid progression of the findings or development of new lesions is seen besides the already existing ones and if this is associated with rapidly increasing dyspnoea. Pulmonary tomography will not yield highly significant results, but it can substantiate the diagnosis, the same applies to computed tomography of the thorax. CT is particularly important in differential diagnosis. Earliest possible diagnosis of lymphangitis carcinomatosa is of great importance for therapy, since it may be a first pointer towards an unknown metastasising primary tumor or haematogenous dissemination of already known tumours.

Adenocarcinoma↗