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Biomedical subjects

D Stiller

Publications and source records attributed to D Stiller.

At least 127 records · Page 7Linked to original sources
PubMed1980

[The cellular and tissue patterns of so-called embryonal rhabdomyosarcomas. Histological and histochemical investigations (author's transl)].

Embryonal rhabdomyosarcomas consist of two histological variants; it can be distinguished between solid embryonal rhabdomyosarcomas and botryoid sarcomas. We investigated 13 solid and 7 botryoid rhabdomyosarcomas and used 46 biopsies of 20 patients between 6 weeks and 14 years old. There were 12 male and 8 female patients. The histologic examination yielded variations of cytologic pattern and tissue structure. Besides undifferentiated sarcoma cells which constituted the majority of tumor cells and a changing amount of rhabdomyoblastic cells (but only 40% of all tumors showed cells with cytoplasmic cross striation) in 6 solid and 6 botryoid tumors some other cellular features could be observed. There were tumor cells with characteristics of lipoblasts and histiocytes, and occasionally the potency to form vascular spaces was detected, too. The histochemical examination proved the presence of glycosaminoglycans and mucoproteins. The glycosaminoglycans seemed to contain only a few sulphated groups. In agreement with a preceding electron microscopic study of botryoid sarcomas in the nasopharynx (Katenkamp et al. 1979) we stated that many so-called embryonal rhabdomyosarcomas show the basic pattern of an undifferentiated embryonal sarcoma and have some diverging cellular differentiations. Therefore, it is an open question whether the term "embryonal rhabdomyosarcoma" should be defined more precisely than usually done in the routine histological work today.

Adolescent↗
PubMed1980

Ornithodoros (alectorobius) amblus (Acarina: Ixodoidea: Argasidae): identity, marine bird and human hosts, virus infections, and distribution in Peru.

Ornithodoros (Alectorobius) amblus Chamberlin 1920, adults previously were described inadequately. Practically nothing was known regarding the identity, hosts, distribution, and biology of this species. We redescribe both sexes, describe the nymph and larva, and present criteria for differentiating these stages from those of other members of the O. (A.) capensis group in the Western Hemisphere. Samples were collected from 13 localities on the Pacific coast and on offshore islands of Peru. Hosts recorded are the Peruvian Brown Pelican, Peruvian Booby, Blue-footed Booby, Red-legged Cormorant, Guanay Cormorant, and Inca Tern. These birds are not long-distance migrants and more widely distributed species of the O. (A.) capensis group have not been found parasitizing them. The life cycle is characteristic of the O. (A.) capensis group; the first nymphal instar does or does not feed. Humans are attacked eagerly by O. (A.) amblus and suffer afterward from severe inflammation and "incredible" pruritus, and possibly from more severe illness. Viruses infecting this tick are Punta Salinas (Hughes serogroup, family unclassified) and Huacho (Reoviridae, genus Orbivirus, Kemerovo serogroup). Dense tick populations cause breeding birds to desert numerous nests; thus, O. (A.) amblus is economically important to the Peruvian guano industry. Certain spiders and lizards may prey on this tick.

Animals↗
PubMed1979

Comparative serologic study of equine piroplasmosis, with card and complement-fixation tests.

An agglutinating antigen and a rapid card test (CT) for equine piroplasmosis was developed. The antigen for the CT was prepared from lyophilized Babesia caballi complement-fixation (CF) antigen. Serum and plasma samples for testing were obtained from known B caballi-infected horses and clinically normal horses maintained at the laboratory. Serum samples also were obtained from horses outside the continental United States, in areas where piroplasmosis is endemic. Comparative CT and CF tests were done on all samples. The CT correctly identified 85% of 192 plasma samples from known infected and normal horses and 92% of 188 serum samples from these same horses. The CT results agreed closely with CF results. There was good agreement between CT and CF results. There was good agreement between CT and CF results on serum samples from horses outside the United States. Of 19 CF-positive samples, 90% were also CT-positive and 92% of 177 CF-negative samples were also CT-negative.

Animals↗
PubMed1979

[Behavior of serum concentrations of immunoglobulins G, M and A in the 1st week of illness in children with bacterial and viral diseases].

The serum concentrations of the immune globulins in children with acute infection of the upper respiratory tract, angina lacunaris, mumps and acute infection of the urinary tract within the first week of illness were analysed. In the adequate age group the values (altogether 540) of healthy and diseased children were confronted and statistically compared. Here the following characteristic changes were shown: the acute infection of the upper respiratory tract was characterized by an increase of IgG. In mumps a decrease of IgA was stated. As to the infections of the urinary tract in the younger age group an increase of IgM existed, in the older age group a decrease of IgA. The results refer to the dynamics of the immune globulins in the initial phase of the individual diseases.

Adolescent↗
PubMed1979

[Studies on the submicroscopic structure of botryoid (rhabdomyo)-sarcomas of the nasopharynx (author's transl)].

Embryonal rhabdomyosarcomas and their botryoid variant are typical soft tissue sarcomas of infancy and childhood. Generally, the tumor cells are thought to be comparable with embryonal rhabdomyoblasts. Nevertheless, many authors do not require the cross-striation of the tumor cell cytoplasm as cytological marker for the diagnosis "rhabdomyosarcoma". In our study we examined the cytology of tissue samples of 4 botryoid sarcomas of nasopharynx with the electron microscope. A varying cytological picture was found. Besides undifferentiated tumor cells constituting the main part of the growths cellular elements with resemblance to fibroblasts, smooth and striated muscle cells, histiocytic cells and lipoblasts were observed. Furthermore, a vasoformative potency of the tumor tissue was occasionally seen. The conclusion is drawn from our results that, replacing the term embryonal rhabdomyosarcoma, such tumors should better be designated as embryonal sarcomas. We think it probable that the present concept of embryonal rhabdomyosarcomas must be revised.

Child↗
PubMed1979

Malignant non-Hodgkin lymphomas of the epipharynx and the mesopharynx including tonsils, paranasal sinuses and neck. Histological reclassification using the "Kiel-classification".

In the present study a re-classification of 96 lymphomas of the epipharynx and the mesopharynx including tonsils, paranasal sinuses and neck region was performed using the Kiel-classification. The histological criteria employed for this procedure were described briefly. 33 cases could be diagnosed as lymphomas of low grade malignancy, 50 cases belonged to the group of high grade malignancy and 13 cases remained unclassifiable. There was a light preponderance of male patients in the whole lymphoma group. The most frequent tumors were immunoblastic lymphomas, followed by immunocytomas, lymphoblastic lymphomas, centroblastic lymphomas, centroblastic/centrocytic and centrocytic lymphomas. Examples of transitions of one lymphoma type into another were demonstrated. The fact must be mentioned that lymphomas of the paranasal sinuses were nearly completely of the immunocytic or immunoblastic type.

Female↗
PubMed1979

[Electron microscopic study of the structural variability of activated Schwann cells].

The structural variability of Schwann cell is studied on transsectioned sciatic nerves of rats using the electron microscope. Corresponding to histological and cytological changes in the proximal nerve stump and in the growing sprouts processes of regression and progression take place in different phases of nerve regeneration. Under this conditions the Schwann-cells can show a considerably varying ultrastructural cytology. Besides typical Schwann cells modulations can be distinguished differing in their organelle composition, such as light-cells, macrophage-like cells and highly synthetic active and roliferative forms. The importance of these cell modulations is discussed in relation to the functional properties of Schwann cells.

Animals↗
PubMed1978

Ultrastructural cytology of human osteosarcoma cells.

The cytology of 6 osteosarcomas was examined by electron microscopy. In keeping with the varied pattern of osteosarcomas seen by light microscopy several types of tumor cells could be differentiated: osteoblast-like, fibroblast-like, chondroblast-like, osteoclast-like and histiocyte-like cells. Moreover, atypical malignant mesenchymal cells and vascular spaces were present. The individual cytoplasmic organelles are not considered to be specific to particular types of cell as seen from the discussion of the significance of rough endoplasmic reticulum, microfilaments and lysosomes. Only examination of the composite pattern of subcellular organelles allows the differentiation of certain cell types. All tumor cells visible in osteosarcomas are considered as modifications of a transformed common progenitor cell. Because of the variegated cytological picture a multipotent mesenchymal cell rather than an osteoblastic cell is assumed to be the ancestor cell.

Adolescent↗
PubMed1978

Ultrastructure of perineurial cells during peripheral nerve regeneration. Electron microscopical investigations on the so-called amputation neuroma.

The ultrastructural morphology of perineurial cells was examined after transsection of the sciatic nerve of rats. The material prepared for investigation was taken from the proximal nerve stump and the so-called amputation neuroma at different times after operation. We found that perineurial cells begin to activate in the first week, and in the further course of regeneration they modulate their cytoplasmic structure corresponding to the function of proliferation or synthesis. Besides the reconstitution of a diffusion barrier the perineurial cells may exert a stabilizing function in regenerating nerve tissue comparable to myofibroblasts in granulation tissue, and may be engaged in remodeling of connective tissue fibers. The relations of perineurial cells to other cells of peripheral nerves under the condition of regeneration are discussed.

Animals↗
PubMed1978

Ultrastructural relations of macrophages to Schwann cells. An experimental study on regenerating peripheral nerves.

The correlations between macrophages and Schwann cells are studied on transsectional sciatic nerves from rats using the electron microscope. As early as 1 day after operation typical macrophages can be found within the endoneurial space of the proximal stump. On the other hand, 1 and 3 days as well as 4 weeks after operation Schwann cells may show cytoplasmic features comparable to that of macrophages. Our findings suggest that (1) macrophages are not able to transform into Schwann cells and (2) Schwann cells can act as phagocytosing cells exhibiting characteristics of macrophages. But in this functional state they can only be diagnosed as Schwann cells if a basement membrane and/or included axons with mesaxons are present.

Animals↗
PubMed1978

[Contractile connective tissue cells and wound healing. Function of myoid fibroblasts in reparative regeneration of mesenchymal tissue].

The present survey deals with processes of wound healing with special regard to fibroblast proliferation. Comparative experimental studies on reparative and regenerative fibroblastic proliferates and findings from the literature point to the importance of a fibroblast modification with myoid structure in certain phases of the reparative regeneration of the connective tissues. The ultrastructural picture of the myoid fibroblasts and their functional significance are discussed with regard to wound healing in man.

Achilles Tendon↗