Alzheimer-related tau-pathology in the perforant path target zone and in the hippocampal stratum oriens and radiatum correlates with onset and degree of dementia

Abnormal phosphorylation of the tau-protein is regarded as a crucial step in the formation of neurofibrillary tangles in the neuronal cell body and neuropil threads in dendrites. We studied the effects of tau-pathology on the clinical expression of dementia in 106 autopsy cases in the entorhinal region, the hippocampal stratum oriens, the stratum radiatum, and the perforant path target zone. The first cytoskeletal lesions were located in the perikarya and dendrites of the pre-alpha cells of the transentorhinal and entorhinal region. Next, abnormally phosphorylated tau-protein (PHF-tau) was found in the neuropil of the CA1-subiculum region. Thereafter, the stratum radiatum and stratum oriens began to be involved in PHF-tau pathology in Braak stage II. In the Braak stages IV and V, the stratum radiatum was completely involved, the stratum oriens increasingly so. Beginning in Braak stage III, we noted cases having PHF-tau pathology in the perforant path target zone of the outer molecular layer of the dentate gyrus. The increase of this pathology with ever greater involvement on the part of the entorhinohippocampal circuit correlated significantly not only with the Braak stages and with the neurochemically determined hippocampal content of PHF-tau but also with the degree of dementia as defined by the clinical dementia rating (CDR) scale. The affection of the stratum oriens in combination with PHF-tau pathology in the stratum radiatum and in the outer molecular layer of the dentate gyrus was encountered almost exclusively in demented individuals (CDR 1-3). These results indicate that axonal PHF-tau pathology in hippocampal pathways presumably is critical for the clinical expression of dementia and may constitute an anatomical substrate of clinically verifiable memory dysfunction in Alzheimer's disease.

Progression of neurofibrillary changes and PHF-tau in end-stage Alzheimer's disease is different from plaque and cortical microglial pathology

In terminal Alzheimer's disease (AD) the frequency of plaques was found to be reduced in single cases. To test this finding in a larger sample, and in order to determine whether the number of plaques labeled with different markers and the distribution of neurofibrillary tangles are correlated positively to each other and to the degree of dementia, a sample of 134 autopsy brains with and 15 without AD-related pathology has been examined. All of the cases were staged according to Braak and Braak. Both the frequency of plaques immunopositive for beta-amyloid, amyloid precursor protein, and apolipoprotein E and that of microglial cells in the cortex and in the white matter were determined semiquantitatively. The content and distribution of PHF-tau was ascertained by ELISA and immunohistochemistry. Both the clinical dementia rating and the global deterioration scale were used as clinical parameters retrospectively. Correlation coefficients were calculated for all parameters and differences were evaluated statistically. With progressive distribution of neurofibrillary tangles and increasing content of PHF-tau the plaque stages and the degree of cortical microglia reaction increased up to the Braak-stages IV and V, thereafter showing a slightly decreasing tendency in the investigated regions. In end-stage AD resorption of beta-amyloid seems to surpass its deposition. The microglial reaction in the white matter correlated neither with the Braak-stage nor with the accumulation of amyloid. With regard to the degree of dementia, both scales correlated well with the pathological changes. Our data show that neuronal cytoskeletal alterations progressively increase with progressive dementia until the end stage of AD in contrast to the frequencies of plaques and cortical microglial cells, and are therefore preferable for staging purposes.

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.

Significance of cell-mediated and humoral immunity in the acute and chronic phase of antigen-induced arthritis in rabbits

In the course of antigen-induced arthritis of rabbit cell-mediated and humoral immune responses were repeatedly tested in order to prove their significance for the acute and chronic phase of inflammation. The arthritis was monitored during the progression of the inflammation by means of the joint swelling and at the end of experiments by histological evaluation of synovitis and cartilage degradation. Following the arthritis induction a strong increase of specific antibodies and of circulating immune complexes was evident. The correlations between antibody levels and joint swellings confirmed that the local formation of immune complexes is responsible for the initiation and perpetuation of arthritis. In the early phase after immunization the responsiveness of lymphocytes to antigenic and mitogenic stimulation was increased, in the late chronic phase of arthritis proliferative responses of lymphocytes to cartilage matrix components were revealed. No direct correlations could be demonstrated between any cell-mediated immune response and the severity of arthritis. The hyperreactivity of cell-mediated immunity is suggested to be responsible for the transition of the acute arthritis into the chronic stage. The deficiency of an effective suppression results in the activation of B-lymphocytes with increased production of antibodies, maintaining the inflammatory process for a long time. Under these conditions the release of cartilage matrix components during the acute joint reaction induces autoimmune responses against cartilage, which could contribute to the chronification of arthritis and to cartilage degradation.

Assay for beta-ureidopropionase by high-performance liquid chromatography

A sensitive assay for beta-ureidopropionase based on derivatization of the reaction product beta-alanine with phenylisothiocyanate has been developed. Purification of the resulting phenylthiocarbamoyl-beta-alanine is achieved on a LiChrospher 100 C18 reversed-phase high-performance liquid chromatography column using an isocratic elution system. Phenylthiocarbamoyl-beta-alanine is detected by its absorbance at 245 nm and quantitated by automatic peak integration referring to a calibration curve. This technique offers a high degree of sensitivity as beta-alanine quantities in the picomole range can be identified. N-Carbamoyl-beta-alanine, the natural substrate of beta-ureidopropionase, does not interfere with the described assay system. The enzymatic reaction is linear for an incubation time of 45 min with enzyme concentrations of 3.2 micrograms/ml.

Changes of immunoregulatory properties and induction of autoimmune reactivity to cartilage in rabbits with antigen-induced arthritis

The chronicity of the antigen-induced arthritis is characterized as dependent on the development of cell-mediated immunity to the antigen, but the exact mechanisms underlying are unclear. We have evidenced decreased suppressor and increased helper cell potential in the early phase of arthritis as result of the immunization procedure. In the late phase of arthritis proliferative responses of spleen lymphocytes to cartilage proteoglycans were revealed which were neither present in immunized animals without arthritis induction nor in the early phase of arthritis. The changes of the regulatory properties on the T-cell level are probably responsible for the transition of acute arthritis into the chronic stage. The deficiency of an effective suppression and/or the increased helper cell potential results in the activation of B- and T-lymphocytes with increased cell-mediated and humoral immune responsiveness to the antigen maintaining the inflammatory process for a long time. In this situation the release of cartilage proteoglycans during the acute joint reaction induces autoimmune responses against cartilage which could contribute to the chronification of inflammation and to cartilage degradation.

Connective tissue reactions in early phases of spontaneous regression of experimental malignant histiocytomas. An electron microscopic study

Interactions between cancer and host are said to comprehend immunologic processes and stromal reactions including an angiofibroblastic response. We studied the latter phenomenon in spontaneously regressing experimental malignant histiocytomas produced by inoculation of an established macrophage-like cell line (WEHI-3) into baby rats. Light and electron microscopic investigations of the tumor tissue showed that there was a clear proliferation of fibroblasts and capillary vessels beginning from the 8th-10th day of the experiment. The vascular structures seemed to be somewhat changed and fibroblasts often displayed close contacts to tumor cells. The significance of these connective tissue reactions is discussed and, finally, the observations led to the conclusion that the angiofibroblastic reaction in the malignant histiocytoma model presented here may actively contribute to tumor breakdown and should not be interpreted as being only a secondary phenomenon after irreversible damage of tumor cells.

Biphasic changes of the immunological reactivity in the course of experimental lectin-induced arthritis of rabbits

A single injection of Lens culinaris lectin (LcL) into the knee joint cavity of non-sensitized rabbits produces an arthritis with an acute and chronic phase, lasting up to one year. The persistence of the lectin in the joint, related to the strong binding affinity of lectins to glycoproteins of connective tissue structures, and the presence of specific antibodies against LcL in the serum after the intra-articular injection make this model comparable to the antigen-induced arthritis. But in our system these conditions are further modified or amplified by the mitogenic activity of LcL itself. The cell-mediated immunity, studied by mitogenic stimulation of peripheral blood lymphocytes, is characterized by a biphasic change in the course of this experimental arthritis. Hyperresponsiveness to stimulation with LcL and Concanavalin A (Con A), decreased Con A-induced suppressor cell activity, and stimulatory serum factors could be detected in the early phase of inflammation. The late phase of arthritis (8 months after the induction) was characterized by hyporesponsiveness to mitogenic stimulation, normal suppressor cell activity and inhibitory serum factors. In spite of the differences of this experimental arthritis to the human rheumatoid arthritis, concerning mainly the initiation and the lack of systemic manifestation, there are surprising similarities between both, not only in the histopathological feature and the chronicity but also in the cell-mediated immune reactions. Therefore, similar pathogenetic mechanisms for the chronic phase can be suggested.

Immunocytochemical demonstration of Con A-receptors on the cell surface of guinea pig peritoneal macrophages

By means of protein A-gold in combination with the replica technique the distribution of Con A-receptors on the surface of guinea pig peritoneal macrophages was investigated. In nonspecifically activated macrophages the arrangement of Con A-binding sites was demonstrated as homogeneous. It could be evidenced that by the combined technique the advantages of the high resolution of transmission electron microscopy could be joined with the possibility of the stereological demonstration of cell surface structures.

Effects of the immunomodulator diacetyl-splenopentin on antigen-induced arthritis in rabbits

Long-term treatment with the immunomodulator diacetyl-splenopentin reduces the severity of chronic joint inflammation and cartilage destruction in rabbits with antigen-induced arthritis. The level of specific antibodies as well as specific and non-specific cell-mediated immune reactivities including the proliferative response of spleen lymphocytes to cartilage proteoglycans in treated animals are lower than in untreated arthritic rabbits. Moreover, suppressor cell activity, which normally decreases during the early phase of inflammation, is enhanced and hyperreactive helper cell potential is reduced. These findings suggest that treatment with diacetyl-splenopentin normalizes the immune regulation, which is disturbed in the early phase of inflammation. This might result in a depression of the hyperreactive immune system including the autoimmunity developed against cartilage. Lowered immune reactivity in the joint in turn reduces the severity of chronic joint inflammation.

[Patient-individual care pathways in phase D neurological rehabilitation]

The "patient-individual neurological care pathways" are a concept for qualified decision-making about rational rehabilitative strategies in the treatment of neurological diseases. Such clinical pathways include available scientific evidence and treatment guidelines. In neurological rehabilitation all treatments have a decidedly interdisciplinary character. All members of the team need highly specialized knowledge, a high potential for teamwork, as well as efficient organisation of work time. Here, computer aided decision-making tools such as the "patient-individual neurological care pathways" facilitate rational decisions and reduce the need for reorganization of therapies. In rehabilitation of neurological patients a symptom-oriented and function-related perspective of the individual treatment goals is indispensable for optimal choice of therapy approaches. This function-oriented classification of patients and creation of individual treatment plans are realized within the Excel-based care pathways. This system has been proved on the one hand as an instrument for streamlining and optimisation and, on the other, as a useful tutoring tool in the medical rehabilitation process.

Cell-mediated and humoral immune responses in guinea pigs sensitized with the thermostable antigen of human granulocytes (TSGA)

Cell-mediated and humoral immune responses are induced shortly after a single injection of the human thermostable granulocyte antigen TSGA to guinea pigs. This was proved by means of the lymphocyte transformation assay and the estimation of MIF and LIF activity in supernatants of antigen-stimulated lymph node cells as well as by immunodiffusion, immunoelectrophoresis and immunohistology. The maximum of the cellular response was observed 10 days after immunization. The antibody production appeared after a lag time and increased continuously thereafter. The antisera of guinea pig yields a strong specific fluorescence in neutrophils and a weak fluorescence in monocytes of man. The humoral immune responses of guinea pig antisera correspond to the results obtained with antisera from rabbits.

Demonstration of lipopolysaccharide (LPS) binding sites on the cell surface of guinea pig peritoneal macrophages by means of immunogold technique

Lipopolysaccharide binding sites of guinea pig peritoneal macrophages were demonstrated by means of immunogold technique. Resident peritoneal macrophages show a strong specific binding of bacterial lipopolysaccharides from E. coli to cell surface structures.

[Heart wall rupture as a grave complication of acute myocardial infarct]

The rupture of the heart wall is a severe complication of the acute myocardial infarction. We found it in 3.5% of the deceased patients with an acute myocardial infarction. The average age of these patients was 71 years. 75% of the patients died during the first five days after the event of the myocardial infarction. Apart from elderly patients with myocardial infarction such ones with a transmural myocardial infarction in the region of the left ventricle, an enlargement of the heart and signs of an insufficiency of the left heart, with a hypertension and diabetes mellitus seemed to be endangered. These patients need the most exact control and observation and in case of suspicion (symptomatology of angina pectoris which is continuing to exist) of a developing rupture of the heart wall and aimed diagnostics (echocardiography) and therapy must be begun immediately.

[Arteriosclerotic changes of the brain and heart in relation to cardiac decompensation and arrhythmia in patients with cerebrovascular insufficiency]

In 150 patients with an acute cerebrovascular insufficiency we asked the following questions: 1. How often appear together the cardiac decompensation and disturbances of cardiac rhythm, 2. symptoms of hypertrophy and disturbances of cardiac rhythm and 3. arteriosclerosis of the cerebral and coronary vessels in deceased patients. The number of patients examined showed 26.7% of patients in whom a combination of symptoms of cardiac decompensation and disturbances of cardiac rhythm was present. The combination of signs of hypertrophy in the electrocardiogram and disturbances of cardiac rhythm was registered 39 times (26.0%). The arteriosclerosis was found in 68.2% of the patients in post-mortem examination. There was a high correlation between the sclerosis of the intracranial cerebral brains (65.9%) and the sclerosis of the coronary vessels (75.0%). It is referred to the possibilities of the prevention of the cerebrovascular insufficiency and the early therapy of hypertony, the cardiac decompensation and disturbances of cardiac rhythm.

Thymocyte stimulating activity of the serum of rats in the early phase after 2-acetylaminofluorene (AAF)-treatment

The serum of rats collected at various time intervals after application of a single dose of 2-acetylaminofluorene (AAF) stimulates the incorporation of 3H-thymidine into the DNA of cultured thymocytes of rats, mice and hamsters. This reaction shows a clear dose-response relationship. The serum activity is dialysable and relatively thermostable.

Killing of untreated target cells by nonimmunized rat macrophages in vitro. II. Ultrastructural studies on the interaction of macrophages and rat liver cells

The sequence of morphological changes following the interactions between macrophages of nonimmunized rats and allogeneic liver cells in vitro were examined by scanning and transmission electron microscopy. The effector cells could be identified as macrophages because of their morphologic characteristics and their ability of latex beads incorporation. The cytotoxic reactions required close contracts between the reactive cells. Effector membrane processes and microvilli attached the target cell surface. Broad contacts and, more frequent, point contacts were observed. After 4 to 5 hrs of incubation the target cells showed pinocytotic activities in the contact regions. Later on submembraneous cytoplasmatic leaks or defects indicated the increasing damage of the target cells. Finally, liver cell ghosts with degenerated organelles were found as morphologic expression of general target cell destruction whereas effector macrophages did not show any damage during the cytotoxic reaction.

[Different antibody tests (IgG, IgM) from children with chronical recurrent urinary tract infections (author's tranls)]

Different Antibody tests (IgG, IgM) were made from children with chronical and recurrent urinary tract infections with help of the indirect fluorescent method and were compared with the indirect hemagglutination test. The indirect hemagglutination gave absolutely higher antibody rest results, but the specifity of the immune fluorescence test is just as large. You can see the acute attacks of pyelonephritis in either the antibody response test or IHA test. It is quite important, in the beginning, to repeat the controlls of the antibody test, because the changes that could occure in the titer should be seen. The IgG antibody reactions rise slightly during the acute attacks of E. coli- and Enterococci reinfections.