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R Jander

Publications and source records attributed to R Jander.

At least 19 recordsLinked to original sources
PubMed2000

Hippocampectomized rats can use a constellation of landmarks to recognize a place.

The hippocampus, one of the most studied regions of the mammalian forebrain, plays some well-established roles in topographic navigation. For two decades, one widely accepted explanation for the observed impairment of hippocampectomized rats in spatial navigation has been an inability to form place representations. In this report, we present a direct experimental evidence that animals with hippocampal lesions can learn to recognize places using the constellation of distinct landmarks. The extrahippocampal implementation of all three basic constituents of topographic orientation - guidance, vector navigation, and place recognition - shows that the hippocampus, and its place cells, serve a much more specialized cognitive function than previously thought. We propose that this function includes multi-place and multi-vector topographic integration.

Animals↗
PubMed2000

Three dimensional path integration in the house mouse (Mus domestica).

Previous studies have explored two-dimensional path integration in rodents by recording responses to passive rotation on a horizontal plane. This study adds the element of passive rotation in a vertical plane, necessitating the mouse to integrate positional information from three dimensions. Mice were trained to climb a wire mesh joining two horizontal planes. The whole arena was rotated 90 degrees while the mouse was vertically oriented as it moved between planes. Rotation was conducted both clockwise and counter-clockwise, controls being provided by rotation of the arena while the mouse was in its nest-box. All 16 mice tested altered their direction of travel subsequent to rotation in the vertical plane, compensating with a change in their path on the following horizontal plane.

Animals↗
PubMed1999

Monarch butterflies (Danaus plexippus L.) use a magnetic compass for navigation.

Fall migratory monarch butterflies, tested for their directional responses to magnetic cues under three conditions, amagnetic, normal, and reversed magnetic fields, showed three distinct patterns. In the absence of a magnetic field, monarchs lacked directionality as a group. In the normal magnetic field, monarchs oriented to the southwest with a group pattern typical for migrants. When the horizontal component of the magnetic field was reversed, the butterflies oriented to the northeast. In contrast, nonmigratory monarchs lacked directionality in the normal magnetic field. The results are a direct demonstration of magnetic compass orientation in migratory insects.

Animals↗
PubMed1990

The primary structure of a triple-helical domain of collagen type VIII from bovine Descemet's membrane.

We have isolated and sequenced a fragment of 469 amino acid residues from bovine type VIII collagen. The sequence was composed of a series of Gly-X-Y repeats which was interrupted 8 times by short imperfections. The number and relative location of these interruptions were similar to those of chicken alpha 1(X) and rabbit alpha 1(VIII) chain triple-helical domains. Comparison to published N-terminal sequences to two triple-helical fragments of bovine type VIII collagen and to the cDNA derived sequence of the rabbit alpha 1(VIII) chain showed that this fragment was the triple-helical domain of a second type VIII collagen chain which we designate alpha 2(VIII).

Amino Acid Sequence↗
PubMed1990

Characteristics and in vivo occurrence of type VIII collagen.

Type VIII collagen was isolated from bovine Descemet's membranes by pepsin treatment and salt fractionation, as described by Kapoor et al. [(1986) Biochemistry 25, 3930-3937]. Contaminating type IV collagen was removed by ion-exchange chromatography. Purified type VIII collagen consisted of two different polypeptide chains and, compared to the fiber forming collagens, showed a higher thermal stability. Corresponding fractions isolated from pepsinized human Ewing's sarcoma and fetal calf aorta reacted immunologically with a protein of similar molecular mass. After extraction of Descemet's membranes with guanidine hydrochloride, a peptide of about 60 kDa was obtained. This seems to be the tissue form of type VIII collagen.

Amino Acids↗
PubMed1990

Type-VI collagen in the human iris and ciliary body.

The distribution of type-VI collagen in the human iris and ciliary body was investigated by means of immunohistochemical techniques and compared with that of type-IV collagen, fibronectin and laminin. As has been described for other tissues, type-VI collagen surrounds type-I and -III collagen fibers. The aggregated form of type-VI collagen (the "long-spacing" or "curly" collagen), which has already been described in the trabecular meshwork and sclera, was also observed at the ciliary muscle tips surrounding the anterior elastic tendons of this muscle. In addition, staining for type-VI collagen was seen directly adjacent to the basement membranes of the ciliary muscle cells, the iris muscles, the uveal vascular endothelia and nerves, but not adjacent to the epithelial basement membranes. The staining did not form a discrete line like the immunoreaction for type-IV collagen, but bundles of marked fibrils extended into the surrounding connective tissue. We assume that type-VI collagen similar to type-VII collagen forms part of an anchoring system for these tissues. As type-VII collagen has been described only in connection with epithelial basement membranes, both type-VI and type-VII collagens may represent anchoring fibrils, however for different tissue components.

Aged↗
PubMed1989

Immunomicroscopical study of type VI collagen in the trabecular meshwork of normal and glaucomatous eyes.

Cross-strained fiber bundles called long-spacing collagen or curly collagen occur in normal eyes in the trabecular meshwork. It can be seen in the basement membrane of the trabecular lamellae, in the sheath of the elastic-like fibers and underneath the inner wall of Schlemm's canal, where it forms part of the so called plaque material. The amount of this long-spacing collagen increases with age and is significantly more pronounced in glaucomatous eyes. Using immunohistochemical and immuno-electronmicroscopic methods, we have been able to show that type VI collagen is present in the aggregates called long-spacing collagen.

Age Factors↗
PubMed1984

A collagen-like glycoprotein of the extracellular matrix is the undegraded form of type VI collagen.

The 140 000-dalton collagenous glycoprotein (CGP) from calf aorta and ligament characterized by Gibson & Cleary (1982) [Gibson, M.A., & Cleary, E.G. (1982) Biochem. Biophys. Res. Commun. 105, 1288-1295] has been studied. In the electron microscope, rotary-shadowed CGP molecules appear similar to the dimers of type VI collagen (short-chain collagen, intima collagen) described by other authors [Furthmayr, H., Wiedemann, H., Timpl, R., Odermatt, E., & Engel, J. (1983) Biochem. J. 211, 303-311] except that they have larger globular domains. As shown by gel electrophoresis, pepsin treatment of CGP at 4 degrees C either before or after reduction releases polypeptide chains corresponding in size to those of type VI collagen. Electron microscopic examination shows that pepsin digestion of nonreduced CGP removes the outer globular domains, reduces the size of the inner ones, and separates the paired central strands. The residual structures look like type VI collagen dimers. When intact CGP is reduced, monomers with two large globular ends are obtained. Pepsin digestion of monomers removes most or all of both globular domains. In immunoblots, CGP and its pepsin-derived fragments react with antibodies directed against type VI collagen. The results indicate that type VI collagen is an integral component of CGP.

Amino Acids↗
PubMed1984

[Treatment of pathologic fractures and its results].

In case of pathologic fractures caused by metastases, operative stabilizing of the fractures is indicated if the general condition of the patient just permits an operation. It is the aim of treatment to reestablish the function of the extremity, to reduce pain and to give psychological support to the patient during his remaining life time. The operative procedure depends on the general conditions of the patient, the spreading and localisation of the metastases.

Adult↗
PubMed1983

Further characterization of the three polypeptide chains of bovine and human short-chain collagen (intima collagen).

Short-chain collagen was isolated from bovine and from human placenta after limited pepsin digestion. By reductive cleavage of disulfide bonds under non-denaturing conditions, mainly non-collagenous domains were cleaved off yielding a uniform component composed of three polypeptide chains with molecular masses between 37 kDa and 48 kDa in a nearly equimolar ratio. The chains (SC1*, SC2* and SC3*) were isolated and characterized. By comparison of peptide patterns obtained after various cleavage procedures, they could be identified as more or less shortened forms of SC1, SC2 and SC3, the isolation of which from bovine short-chain collagen has been described [Jander et al. (1981) Eur. J. Biochem. 114, 17-25]. The peptide patterns; as well as N-terminal sequence determination, give evidence for the genetic individuality of the three chains; the data so far available suggest that together they form one triple-helical structure which represents the collagenous domain of the basic molecular unit of short-chain collagen.

Amino Acids↗
PubMed1982

Instillation of fibrinolytic enzymes in the treatment of pleural empyema.

Acute pleural empyema which is not amenable to pleural puncture or closed thoracic drainage should be treated operatively by decortication or, in persistent cavities, by open thoracostomy drainage. In the last 2 years we have instilled 500,000 IU of fibrinolysines (streptokinase and streptodornase) per day into the pleural cavity of 27 patients with pleural infections requiring closed intrapleural drainage. By means of this treatment, pus and fibrinous membranes are liquefied and necrotic tissue is discharge. Therapeutic success is indicated by considerably increased fluid drainage about one hour after instillation. This therapy was performed for an average of 5 days. In 12 patients (44%) pleural empyema could be cured. In the other 15 cases decortication, and in 3 of them open thoracostomy drainage, was necessary. In our opinion intrapleural instillation of fibrinolytic enzymes should be added to the well-recognized method of treatment of pleural empyema, although not replace them.

Acute Disease↗
PubMed1980

[Alloplastic tracheal prosthesis with biocarbone. A study of animal experiments (author's transl)].

Animal experiments have shown bicarbone to be a suitable material for alloplastic tracheal replacement. So far survival rates have been limited by connective tissue stenoses and by loosening prostheses. Although the transplants are not lined by bronchial mucosa, the movement of secretions is not seriously impaired due to the smooth surface. It is still a matter of speculation as to whether modifying the suture technique with a more elastic transistion from the trachea to the prosthesis would produce better results.

Animals↗
PubMed1980

Osteoclastoma-like giant cell tumor of the lung.

Rare extraskeletal locations of osteoclastoma-like giant cell tumors have been found in thyroid, pancreas, breast, skin and heart. In our case, a 40-year-old male patient, such a tumor was found in the left upper lobe bronchus with atelectasis due to bronchial obstruction. Upper lobe resection was done. As far as we know, this has not been reported.

Adult↗