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Biomedical subjects

K Neumann

Publications and source records attributed to K Neumann.

At least 163 records · Page 9Linked to original sources
PubMed1990

Prognostic significance of nucleolar organizing regions (NORs) in carcinomas of the sigmoid colon and rectum.

The prognostic significance of silver-binding nucleolar organizing regions (AgNORs) has been evaluated in tissue sections of biopsies taken from 70 primary adenocarcinomas of the colon sigmoid (n = 25) and rectum (n = 45) prior to their curative resection. A significant correlation between five-year survival rate and the mean AgNOR number per tumour cell (p less than 0.001) and the mean size of silver stained dots (p less than 0.05) was found according to the univariate Kaplan-Meier survival analysis. There was no significant relationship between AgNOR content and grade of malignancy, pT categories or pN categories. Multivariate survival analysis of covariates (Cox regression model) revealed a set of five variables that significantly influenced the patients' outcome: pN categories, AgNOR content, pT categories, maximum grade of malignancy and number of inflammatory cells. From the clinical and pathological parameters studied, pN and pT categories as well as the mean AgNOR number were the most important variables predicting death from colorectal carcinoma. Since the analysis of AgNORs can be performed on routinely processed paraffin-embedded tissue, this method may be of potential use in pretherapeutic assessment of the biologic aggressiveness of the disease.

Adenocarcinoma↗
PubMed1990

Cooling rate and ice-crystal measurement in biological specimens plunged into liquid ethane, propane, and Freon 22.

Specimens sandwiched between copper planchettes were plunged up to a depth of 430 mm into coolants used for cryofixation. Hydrated gelatin containing a miniature thermocouple was used to mimic the behaviour of tissue during freezing. Gelatin and red blood cells were used for ice-crystal analysis. Ethane produced the fastest cooling rates and the smallest ice-crystal profiles, and Freon 22 produced the slowest cooling rates and the largest crystal profiles. Smaller crystal profiles were often seen in the centre of the specimens than in subsurface zones. The results show that ethane, rather than propane, should be used for freezing metal-sandwiched freeze-fracture specimens by the plunging method, and probably also in the jet-cooling method. They further suggest that good cryofixation could occur at the centre of thin specimens rather than only at their surfaces. Comparison between theoretical and experimental ice-crystal sizes was satisfactory, indicating that where the experimental parameters can be defined then realistic predictions can be made regarding cryofixation results.

Chlorofluorocarbons, Methane↗
PubMed1990

Monoclonal antibodies against antigens expressed by human sperm.

The production and characterization of 21 mouse monoclonal antibodies (TüS1-TüS21) with specificity predominantly for human spermatozoa antigens is described. Reactivity of cells from human ejaculates, peripheral blood and several organs was determined using the alkaline phosphatase-anti-alkaline phosphatase (APAAP)-technique as well as the indirect immunofluorescence test. 15 of the monoclonal antibodies reacted with various regions of human sperm and often also with their precursor cells in the testis. Cross-reactivity with animal spermatozoa was frequently observed.

Acrosome↗
PubMed1990

Establishment of rat endometrial cell lines by retroviral mediated transfer of immortalizing and transforming oncogenes.

To study hormone responsive genes in differentiated epithelial cells and as a model for endometrial carcinoma, lines were established from primary rat endometrial cells by infection with replication-defective retroviruses carrying oncogenes and the selectable gene neo. The initial step involved immortalization through the large T antigen of SV40 to generate a line we designate RENT4, or with the E1a gene of adenovirus to generate lines referred to as RENE1 and RENE2. Additionally, lines generated by large T antigen of SV40 were superinfected with a replication-defective retrovirus harboring the v-Ha-ras oncogene and selected by the ability to form colonies in soft agar. The latter cell lines appeared fully transformed and were designated RENTR01 and RENTR03. Five established lines were characterized for steroid hormone receptors, alkaline phosphatase activity and their complement of the intermediate filaments vimentin and cytokeratin. With the exception of the RENE1 cells all other lines have normal levels of glucocorticoid receptor, whereas only RENE1, RENE2 and RENT4 were positive for the progesterone receptor. RENTR01, RENTR03 and, to a lesser extent, RENE1 exhibited differential expression of cytokeratins dependent upon whether the cells were grown on a substrata of NIH3T3 cells. When grown on formalin-fixed NIH3T3 cells, RENTR01 and RENTR03 cells appeared to differentiate or rearrange themselves in culture. Individual islands of cells showed a heterogeneous pattern of intermediate filaments with vimentin-positive cells localized to the outer portion of the islands whereas cytokeratin-positive cells are seen on the insides of these structures.

Alkaline Phosphatase↗
PubMed1990

[Single cell fluorescence photometry for quantification of antigens on alveolar macrophages].

The quantitation of cell surface antigens on alveolar macrophages (AM) using flow-cytometry is complicated by strong autofluorescence and wide variation of cell- size and autofluorescence. Therefore a microscope-fluorometric method was developed which allows simultaneous assessment of fluorescence of fluorochrome-labelled monoclonal antibodies and size in individual cells. Autofluorescence of smokers AM was found to be variable and considerably stronger than autofluorescence of nonsmokers AM. By means of a multi step determination of autofluorescence and specific fluorescence using different filter combinations of the microscope fluorometer density of membrane bound HLADR-antigens could be efficiently determined also in strongly autofluorescent smoker AM.

Antigens, Surface↗
PubMed1990

[Bronchial carcinoma associated with pulmonary osteoarthropathy (Marie-Bamberger)].

Hypertrophic pulmonary osteoarthropathy (HPO) is characterised by clubbed, or drumstick, fingers and a painful periostitis of the extremities, and occurs most frequently as paraneoplastic symptom in association with bronchial carcinoma. Much rarer are inflammatory pulmonary changes such as lung abscesses. Curative treatment of the underlying disease will always also alleviate the pain in the extremities. This article reports on a case of a bronchial carcinoma masked by a pulmonary abscess. Despite the treatment of the abscess the patient developed the typical pattern of signs and symptoms of hypertrophic pulmonary osteoarthropathy for the bronchial carcinoma which was identified only later and which had been masked by the abscess. Persistence of hypertrophic pulmonary osteoarthropathy in case of a successfully treated pulmonary abscess should, therefore, always be regarded as a possible pointer towards an undetected bronchial carcinoma.

Adult↗
PubMed1990

[Simplified storage procedure of cryopreserved human parathyroid tissue].

Parathyroid tissue that is stored for replantation purposes is usually kept in a special tank containing fluid nitrogen at -196 degrees C. Our studies demonstrate that storage is also possible in a deep-freezer at -70 degrees C without any loss of quality. Most hospitals own such freezers for storing bone marrow cells at the same temperature. Parathyroid tissue of 11 patients who were operated on because of primary hyperparathyroidism was stored in this way. After six months the tissue showed 75.7% morphologically intact cells. The control group's tissue was stored in liquid nitrogen according to the common method; after the same period of time it showed 76% histologically normal cells.

Adenoma↗
PubMed1990

[Infection of the knee joint--an arthroscopic challenge?].

Unlike previous forms of surgical treatment, operative arthroscopy of the septic knee can prevent in most cases severe functional deficit or even ankylosis provided that arthroscopy is done within 1 week after the onset of the infection and that consistent and continuous passive motion is then carried out. In all other cases, open subtotal synovectomy is preferable to closed-irrigation suction drainage. In three-quarters of the cases presented, the functional results can be considered good. Reoperations have only been necessary when arthroscopy has been delayed by more than 1 week.

Adolescent↗
PubMed1989

Clinical relevance of histologic subtyping in small cell lung cancer.

Histopathologic specimens from 249 patients with small cell lung cancer (SCLC) were reviewed and classified into oat cell-type, pure intermediate cell-type (excluding specimens with mixed small cell/large cell features), and small cell/large cell-type. One hundred seventy (68%) specimens displayed oat cell features (including 30 with mixed oat cell/intermediate cell features), 66 (27%) displayed intermediate cell features, and 13 (5%) displayed mixed small cell/large cell features. No differences among these subtypes were found with respect to stage of disease, sex, age, performance status, and number and distribution of metastases. Complete and partial remission rates for the oat cell-type were, respectively, 31% and 38%, for the intermediate cell-type 20% and 45%, and for the small cell/large cell-type 38% and 31%. Two-year survival rates were 7%, 11%, and 15%, respectively. These data were all statistically insignificant, and comparisons of log-rank analyses of survival curves for these SCLC subtypes also showed no statistically significant differences. We thus conclude that histologic subtypes of SCLC are not distinct entities of clinical relevance, and that prognostic as well as therapeutic decisions cannot be based on histologic subtyping.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

[Central pontine myelosis. Morphology and forensic importance].

Central pontine myelinolysis (CPM) evidently occurs more frequently than had been assumed up to now owing to the cases that have been substantiated solely on the basis of pathological anatomy. Its genesis is still unclarified. Computed tomography and magnetic resonance methods allow detection of the foci while the affected person is still alive. They are clearly capable of regression and are not automatically accompanied by a poor prognosis. Since an iatrogenic factor (forced compensation of hyponatremia) is increasingly under discussion as the cause of CPM, the condition also has substantial significance from a forensic point of view. On the basis of a prospective study on CPM confirmed in 100 brains of alcoholics, as well as 4 further cases from the forensic autopsy material, it is shown that hyponatremia is not likely to be the sole triggering factor. The course of the condition in the cases investigated shows that the capacity for action may be preserved up to death (which has occurred for other reasons) in not very pronounced CPM. In questionable violent and other unclear deaths, CPM must also be considered a possible cause of death. The various hypotheses on its etiology in the extensive literature are compared with the findings in our own cases and discussed.

Adult↗
PubMed1989

Tetanus toxin as a marker for small-cell lung cancer cell lines.

Tetanus toxin labeling of human lung cancer cell lines was investigated using direct and indirect immunofluorescence and immunohistochemical staining. Cells of characterized permanent cell lines, eight small-cell lung cancer (SCLC) cell lines of classic subtype, six SCLC cell lines of variant subtype and seven non-small-cell lung cancer (NSCLC) cell lines, were incubated with a saturating concentration of tetanus toxin. For staining, fluorescein-isothiocyanate-(FITC)-conjugated anti-(tetanus toxin) antibodies were used or a mouse monoclonal anti-(fragment C) antibody with subsequent binding of FITC-conjugated anti-(mouse Ig) antibody or peroxidase-anti-peroxidase complex. Only SCLC showed an intense fluorescence/immunoreactivity restricted to the cell membrane. Quantitative analysis of tetanus toxin labeling by flow cytometry revealed the percentage of positive cells to be between 35% and 95% in SCLC without obvious differences between the classic and variant subtypes of SCLC. In NSCLC the percentage of positive cells was lower than 10%. These results demonstrate that SCLC in contrast to NSCLC can be labeled with tetanus toxin, emphasizing the neuroendocrine properties of this tumor, and that tetanus toxin labeling may become a useful diagnostic marker for SCLC cells in cytology.

Animals↗
PubMed1989

[Dislocation and subluxation of the patella].

Subluxations or dislocations are present in adolescents and young adults, they are caused by malalignments of the leg (rotation, axis, extensor mechanism). In subluxation, functional therapy is the method of choice, dislocations with haemarthrosis are an indication for arthroscopy. After the first dislocation without chondral lesion, consequent functional treatment has a recurrence rate of only 5 per cent. Recurrent dislocations need a reconstruction of the extensor mechanism to prevent chondral damage.

Adolescent↗