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Biomedical subjects

H Rose

Publications and source records attributed to H Rose.

At least 109 records · Page 6Linked to original sources
PubMed1978

[Ratio of cyclo-3':5'-adenosinemonophosphate to cyclo-3':5'-guanosine-monophosphate in human tumor tissue].

In human tumor tissues of different degrees of differentiation--nevus-cell-nevus, basalioma, malign melanoma--the cAMP and cGMP content was determined and compared with the corresponding normal values. It is demonstrated that the quotient of the cAMP to the cGMP values is of importance rather than the latter values for themselves. For the benign tumor, this quotient differs only slightly from that of the adjacent normal, sound tissue. On the other hand, for the two malign tumors a drastic decrease of the quotient as compared to that of the normal tissue was found to occur.

Basal Cell Carcinoma↗
PubMed1978

[The correlation of in vivo and in vitro effect of cytostatics in transplantated tumours of the mouse (author's transl)].

In 2 inoculated mouse tumours the conformity of the actions of 4 different cytostatics at 2 dose levels was tested in vitro and in vivo. The histochemical reaction of lactate dehydrogenase and NADH diaphorase was taken as a criterion of the cytostatic action. The investigations showed the tumours used responded to the cytostatics employed. A good conformity of the in vitro and in vivo findings was established. The histochemical assessment of organ cultures following the administration of cytostatics allows to determine the sensitivity of tumours and helps the physician in deciding on an effective therapeutic.

Animals↗
PubMed1977

Nonstandard imaging methods in electron microscopy.

A rigorous treatment of image formation, taking into account inelastic scattering and partially coherent illumination, is given for the CTEM. The results also hold for a STEM if the momentum vectors of the incident and outgoing waves are interchanged and the flight direction of the electrons is reversed. A generalized optical theorem is found which connects the anti-Friedel part of the elastic scattering amplitude with the squares of the elastic and inelastic scattering amplitudes. This theorem has important consequences for all approximation methods. For example, it shows that inelastic scattering influences the elastic scattering amplitude. It is further shown that the observed wings in optical diffractograms, obtained from micrographs of amorphous material taken using tilted beam illumination, can only be explained if double scattering (elastic and inelastic) is assumed. Hollow-cone illumination strongly suppresses the structural noise in the phase contrast image. The corresponding phase contrast transfer function (PCTF) is calculated for two different cone angles, assuming that no beam-limiting aperture is present. In addition, the PCTFs of a corrected microscope are calculated for two different illumination modes, one yielding negative and the other positive phase contrast. Finally, the contrast transfer has been investigated for a stem operating with a split detector.

Lighting↗
PubMed1977

A reflection on partial coherence in electron microscopy.

The concept of partial coherence, which originated in light optics, is investigated in the case of dark-field electron microscopy. Two atoms arbitrarily arranged in the object space are considered as sources of the secondary waves. The influence of lens aberrations is taken into account. The real degree of coherence gamma r is calculated for the STEM as well as the CTEM. In the case of atomic resolution, the finite size of the atoms significantly influences the degree of coherence, so that it becomes a function of the image coordinate. Analytical expressions are obtained for gamma r which are valid at present-day resolutions for both the CTEM and STEM. The dark-field intensity distribution in the detector plane of a STEM is calculated for an object consisting of two atoms in different configurations and for different positions of the scanning spot.

Microscopy, Electron↗
PubMed1977

[Nuclear alterations on organ cultures of human malignant melanomas (author's transl)].

Report on ultrastructurally striking nuclear anomalies in organ cultures obtained from amelanotic and pigmented human melanomas. These nuclear anomalies are more impressive than the nuclear invaginations present in tumours cells of several other malignant growths. Numerous nuclear fragments varying in size and held together by nuclear membrane bands may occur. The karyoplasm of these nuclei reveals nothing unusual no degenerative changes can be found.

Cell Nucleus↗
PubMed1977

[Histochemical and ultrastructural investigations on the activity of methylglyoxal (bis)-guanylhydrozan (methyl-GAG) on organ cultures of malignant tumors (author's transl)].

Methyl-GAG was tested in organotypic cultures of malignant tumors of human and mice. In 3 cases, a reduction of the activity of two oxydoreductases (lactate dehydrogenase and NADH-diaphorase) after treatment with methyl-GAG was observed whereas in 19 other cultivated tumors no change of enzyme activity was induced by methyl-GAG. Electronmicroscopy revealed only minor structural alterations of tumor cells after application of methyl-GAG as compared with control cultures.

Animals↗
PubMed1977

[Investigations on acceleration of processes of differentiation and aging in rats after influence of x-ray (author's transl)].

On the basis of the hypothesis of a relation between the processes of differentiation and aging in connection with the assumption, that ionizing radiation accelerates the aging of organism, the authors investigated the changes in the cellular reaction in organ cultures of the spleen and the kidney, in the pattern of enzymes in the kidney and the liver and moreover the behaviour of the serum protein level. In dependence of the x-ray dosis and the length of time after radiation an acceleration of the processes of maturation and differentiation could be observed with the three above mentioned methods. Changes could be found which were similar to those, observed in adult or senile rats. The latent phase or organ cultures was prolonged as well as the morphology of cells migrating out of the explants did not differ from that of senile donor animals. The chemical differentiation of the kidney is accelerated after radiation. The detected changes were similar to those in adult or senile rats. The increase in the albumin, haptoglobin and transferrin concentrations of juvenile rats following radiation mean an acceleration of development, for these concentrations are attained during normal development. The authors discuss their results with reference to the existing theories of aging.

Aging↗
PubMed1977

[Biological bases of aging].

The author discusses ageing with special regard to evolution processes. Accelaration and retardation of certain ontogenetic phases or the whole ontogenesis have developed during phylogenesis and have been fixed genetically as a special reaction norm. The limitation of life span in highly differentiated organisms after reproduction is perfected has to be considered as one of the preconditions of evolution. Considering the phylogenesis, those hypotheses which interpret ageing as a continuous accumulation of cell damage, are no longer admissable. The different theories of the genetic control for ontogenesis are discussed on the basis of international literature.

Aging↗
PubMed1976

Influence of detector geometry on image properties of the STEM for thick objects.

Plural electron scattering within thick objects broadens and smoothes the intensity distribution in the detector plane of a scanning transmission electron microscope. Detector arrangements have been determined which give maximum contrast and optimum S/N when the object details are large compared to the scanning spot. Asymptotic expressions for the optimum detector angles, specimen resolution, and S/N were obtained which are valid for objects thicker than approximately four elastic mean free path lengths. Exact calculations of the changes in contrast and S/N with thickness fluctuations in amorphous carbon foils were performed for atbitrary foil thicknesses. Elastic and inelastic electron scattering was taken into account.

Carbon↗