Image states and local work function for Ag/Pd(111).
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to R Fischer.
Explore the source record for details and available documents.
Excimer laser is used for cartilage debridement, although the resulting cell damage is yet unclear. For examination of cartilage survival after treatment, we used short-term tissue cultures of human joint cartilage. Specimens were treated with a XeCl-Excimer laser using different laser parameters, pulse energies, and repetition rates. Following treatment, discs were cultured for 8 days prior to examination. In contrast to the 20 microns damage zone as instant visible effect in histomorphologic examinations, we found a 0.3 mm zone in which approximately 50% of cartilage cells had morphological signs of damage on light microscopic examinations. Autoradiography revealed that cartilage cells in an 0.5-0.7 mm area surrounding the laser craters had no collagen synthesis. This examination indicates that cell damage of excimer laser is higher than expected from prior studies.
The lineage of Hodgkin and Reed-Sternberg cells is still unclear. Detection of both immunoglobulin light chains in Hodgkin and Reed-Sternberg cells by immunohistochemistry is a well-known phenomenon. However, up to now, in situ hybridization techniques have failed to demonstrate light chain messenger(m) RNA in Hodgkin and Reed-Sternberg cells. In this investigation, we have analysed 26 cases of Hodgkin's disease (nodular lymphocyte predominant Hodgkin's disease, mixed cellularity, and nodular sclerosis type) using digoxigenin-labelled oligonucleotide probes for kappa and lambda light chains by in situ hybridization. In nearly half of the cases of nodular lymphocyte predominant Hodgkin's disease and in one case of mixed cellularity type, mRNA for only one light chain could be clearly demonstrated in the lymphocytic and histiocytic cells, Hodgkin, and Reed-Sternberg cells. These results support the idea that at least some cases of Hodgkin's disease are B-cell neoplasms.
We report our results with abdominal rectopexy (modified Ripstein procedure, Ripstein/Corman) without resection of the colon in 63 patients using lyophylized dura-strips, Vicryl gauze or Dexon gauze, as the underlying fixation material for the mobilized rectum, presacral fascia and fixation suture material. Forty-five of 64 patients (71.4%) were reevaluated by proctoscopic examination and questioning; the mean follow-up time was 52.5 months (range 3-136 months). Postoperative mortality due to the method was 0%; the mortality was 1.6% (n = 1/63) in general for the first postoperative 30-day period as a result of cardiac complications. There were three complications (4.7%) the durating operation. Postoperative morbidity was 25.4% (16/63); infectious complications occurred in 12.7% (8/63) of cases, with one case of spontaneous closure of a pelvicutaneous fistula after intraoperative injury to the rectal wall. Full-thickness rectal prolapse appeared after rectopexy in 4.4% (2/45) (dura material alone) and mucosal prolapse was seen in 15.5% (7/45) of the follow-up group. Constipation was reduced by 28.6% (18/63) to 22.2% during the follow-up. Seventeen of 28 patients (60.7%) with incontinence showed an improvement; total continence was registered in 35.7% (10/28). The increase in continence as a result of abdominal rectopexy was significant (Wilcoxon, P = 0.05). The special aspects of being in an older age group, having a long history of procidentia, the number of deliveries, the length of the preoperative incontinence period all showed no influence on the postoperative degree of continence (Spearman's rank correlation). In 7/15 cases with persisting incontinence after rectopexy, postanal repair (Parks) was efficient in 7/7 cases leading to total or partial continence.(ABSTRACT TRUNCATED AT 250 WORDS)
The production of the cytokines interferon gamma (IFN gamma), interleukin-1 alpha (IL-1 alpha) and tumor necrosis factor alpha (TNF alpha) was investigated in the mitogen-stimulated whole blood cell culture media from 51 patients with urinary bladder carcinomas, 52 patients with renal carcinomas, 31 patients with prostatic carcinomas and 360 healthy controls. The cytokines were measured 4 days after induction by a sensitive enzymo-immunological assay. In the blood cell culture supernatants of the patients with urinary bladder carcinomas significant lower levels of IFN gamma (P < or = 0.001), IL-2 (P < or = 0.01) and TNF alpha (P < or = 0.05) were found as compared to the controls. Blood cells of patients with renal carcinomas had lower production of IFN gamma (P < or = 0.01), IL-2 (P < or = 0.001) and IL-1 alpha (P < or = 0.01), whereas the values of the total group of patients with prostatic carcinomas were not significantly different from those of the controls. Lymphocyte and monocyte counts were almost identical in the control and all tumor patient groups. When the patients with renal carcinomas and prostatic carcinomas were analyzed according to their different clinical stages we could show a gradual depression of the IFN-gamma levels, which was related to tumor burden.
An immunohistochemical and morphometric analysis was performed on bone marrow trephine biopsies in 40 patients with primary myelodysplastic syndromes (MDS) to evaluate the proliferative activity in erythropoiesis and the endoreduplicative capacity of megakaryocytes. Control groups included normal bone marrow and marrow from cases presenting with pernicious anaemia. Double-immunostaining was applied with a monoclonal antibody (PC10) directed against proliferating cell nuclear antigen (PCNA), followed by antibodies against glycophorin C (Ret40f) or platelet glycoprotein IIIa (Y2/51-CD61) for the identification of the erythroid and megakaryocytic cell lineage. Comparison with normal bone marrow showed a reduction of erythropoiesis accompanied by an increase in atypical (micro-) megakaryocytes. Erythroid precursors displayed significant enhancement of PCNA-immunostaining. Megakaryocytes showed no increase in the relative frequency of PC10-positive cells (PCNA-labelling index). In pernicious anaemia, predominance of macrocytic-megaloblastoid erythropoiesis was associated with a striking increase in PCNA-labelling. Cell kinetic studies in this disorder revealed an abnormal arrest, particularly in S-phase which generates an over-expression of PCNA. Similar conditions were believed to be present in MDS with secondary folate deficiency. This mechanism explains the relatively high rate of positively-reacting pro- and erythroblasts which is not invariably accompanied by an increase in cell proliferation. Determination of megakaryocyte size and PCNA-staining capacity resulted in a significant increase in PC10-positive cells among micromegakaryocytes. Our findings on this cell lineage are in keeping with the assumption of a block in endoreduplicative activity at higher ploidy levels, associated with an apparently not-deregulated endomitosis in small-sized megakaryocytes of lower ploidy stages.
Explore the source record for details and available documents.
To evaluate the prognostic significance of clinical as well as histological disease features at the time of diagnosis, an immunohistochemical and morphometric study was performed on bone marrow trephine biopsies in 130 patients with Ph(1+)-CML. For identification of all cell elements of the megakaryocytopoiesis we used the monoclonal antibody CD61 (Y2/51) and for the macrophages, the recently characterized antibody PG-M1. Density of argyrophilic fibers was determined per fat cell-free marrow area. Based on a multivariate analysis-derived risk model, the reproducibility of the prognostic score described by Sokal and co-workers was tested, particularly with regard to histological variables. Additionally, we calculated the disease-specific loss in life expectancy. Our prognostic model (Cox model) consisted of the variables: age, spleen size, peripheral erythro-normoblasts, pseudo-Gaucher cells, and fiber density. To assess the validity of this new CML score, a receiver-operating curve (ROC) of sensitivity and specificity was constructed. The improved prognostic efficiency of this newly developed risk model in predicting death within 3 years after diagnosis of CML was demonstrated in comparison with generally accepted staging systems. Immunohistochemistry revealed that not the total number of macrophages, but only the subfraction of pseudo-Gaucher cells exerted a significant impact on survival. Furthermore, it was feasible to calculate the number of atypical micromegakaryocytes and pro- and megakaryoblasts. This abnormal and immature cell population showed a significant correlation with fiber density and prognosis. Finally, the practical value of the Hannover classification was tested. This histological classification enabled a discrimination between two groups with different survival patterns, i.e., granulocyte and/or megakaryocyte-rich subtypes versus subtypes with increase in reticulin and collagen fibers.
In the presence of hemopoietic cytokines such as granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-3 (IL-3), mast cell growth factor (MGF; also known as steel factor, stem cell factor, and c-kit ligand) has proven to be a potent hemopoietic regulator in vitro. In these studies, we examined the in vivo effects of MGF in combination with GM-CSF or GM-CSF plus IL-3. Effects were based on the ability of these cytokines to stimulate recovery from radiation-induced hemopoietic aplasia. Female B6D2F1 mice were exposed to a sublethal 7.75-Gy dose of 60Co radiation followed by subcutaneous administration of either saline, recombinant murine (rm) MGF (100 micrograms/kg/day), rmGM-CSF (100 micrograms/kg/day), rmIL-3 (100 micrograms/kg/day), or combinations of these cytokines on days 1-17 postirradiation. Recoveries of bone marrow and splenic spleen colony-forming units (CFU-s), granulocyte macrophage colony-forming cells (GM-CFC), and peripheral white blood cells (WBC), red blood cells (RBC) and platelets (PLT) were determined on days 14 and 17 during the postirradiation recovery period. MGF administered in combination with GM-CSF or in combination with GM-CSF plus IL-3 either produced no greater response than GM-CSF alone or down-regulated the GM-CSF-induced recovery. These results sharply contrasted results of in vitro studies evaluating the effects of these cytokines on induction of GM-CFC colony formation from bone marrow cells obtained from normal or irradiated B6D2F1 mice, in which MGF synergized with GM-CSF or GM-CSF plus IL-3 to increase both GM-CFC colony numbers and colony size. These studies demonstrate a dichotomy between MGF-induced effects in vivo and in vitro and emphasize that caution should be taken in attempting to predict cytokine interactions in vivo in hemopoietically injured animals based on in vitro cytokine effects.
Using monoclonal antibodies against proliferating cell nuclear antigen or PCNA (PC10) and the Ki-67 antigen (MIB1), an immunohistochemical and morphometric study was performed on routinely processed splenic tissue from ten patients with primary (idiopathic) osteomyelofibrosis (OMF). To determine the proliferation capacity of erythroid precursors and the endoreduplicative activity of megakaryocytes, corresponding antibodies (Ret40f and CD61) were applied in combination with the cell-cycle markers (sequential double-immunostaining). Morphometric analysis revealed no significant differences in PCNA or Ki-67 reactivity in either cell lineages. In comparison with previous studies on normal bone marrow, in splenic tissue showing myeloid metaplasia, the numbers of PCNA-labelled proerythroblasts, erythroblasts and megakaryocytes were conspicuously increased. Considering the ineffective erythropoiesis in OMF, there seemed to be a disproportional enhancement in PCNA and Ki-67 immunostaining of the red cell lineage. Similarly, the small size of megakaryocytes in advanced, OMF-associated myeloid metaplasia was in keeping with an impairment of endoreduplicative activity. In addition to various other contributory factors, anaemia in OMF may be partially caused by secondary folate (haematinic) deficiency. From experimental studies this defect is known to cause an abnormal arrest in the S-phase of the cell-cycle, comparable to that characterising pernicious anaemia. As a sequel of this pathomechanism, an undue overexpression of PCNA and Ki-67 has to be assumed, that is not necessarily associated with DNA synthesis or cell cycling.
1. Physiological concentrations of ascorbic acid inhibited PTPase activity in HER 14 cells. 2. Higher concentrations of ascorbic acid produced a weaker inhibitory effect on PTPase activity in HER 14 cells. 3. EGF prevented the inhibitory effect of ascorbic acid on PTPase activity in HER 14 cells. 4. The inhibitory effect of physiological concentrations of ascorbic acid on PTPase activity depends on density of the cell culture, with less dense populations exhibiting greater inhibition of PTPase activity. 5. These observations suggest that ascorbic acid might have a modulatory role in cellular phosphorylation-dephosphorylation events.
Pb(p, xn) thick target excitation functions were measured in the energy range 10-38 MeV in order to optimize the production of isotopically pure radiobismuth from natPb, 206Pb, and 207Pb. Additionally, the decay of Po-isotopes from deuteron irradiation of natural bismuth (209Bi) was exploited for radiobismuth production. 205Bi was produced from 206Pb at 20 MeV with only 2% of 206Bi at 4 weeks post irradiation. Bismuth compounds as used in the treatment of peptic ulcer were labeled with 205Bi for absorption studies in animals and subjects.
OBJECTIVE: To assess the endocrinologic and clinical outcome after laparoscopic ovarian electrocautery because of polycystic reaction to ovarian stimulation in anovulatory infertility patients. DESIGN: Between 1986 and 1989, 133 patients with polycystic ovarian disease underwent laparoscopic electrocoagulation of the ovarian surface in an outpatient clinic after conventional ovarian stimulation had led to polycystic reaction. SETTING: All patients were referred to our outpatient clinic affiliated with the university hospital. RESULTS: The reduction of androgen levels and normalization of cycle length were highly significant. The overall pregnancy rate was 70% (73 of 104), ranging from 27% in smokers to 94% in nonsmoking couples. In 26 second-look operations de novo adhesions were found in 26.9% of the patients. CONCLUSION: Laparoscopic coagulation of the ovarian surface is an effective tool to reduce elevated androgen levels and to improve the intraovarian mechanism of selecting a dominant follicle. A postoperative complication may be adhesion formation.
OBJECTIVE: To evaluate the incidence and extent of periovarian adhesion formation subsequent to laparoscopic electrocoagulation of the ovarian surface in infertility patients with polycystic ovarian disease (PCOD). DESIGN: From a total of 199 PCOD patients treated with ovarian electrocautery, 50 cases of laparoscopy and 12 cesarean sections served as second-look investigation. A subgroup of 30 patients had abdominal lavage and artificial ascites after surgery; they underwent "early" second-look (2 to 14 days after laparoscopy). SETTING: All patients were referred to our fertility outpatient clinic affiliated with the university hospital. PATIENTS: Infertility patients with polycystic ovarian reaction to hormonal stimulation therapy underwent laparoscopic electrocoagulation of the ovarian surface. RESULTS: Adhesion formation was detected in 19.3%; the incidence reduced to 16.6% with the use of abdominal lavage. The adhesions found were obviously due to bleeding of the ovarian capsule caused by electrocautery. Adhesiolysis was easily possible during "early" second-look. CONCLUSION: The incidence of de novo adhesion formation caused by laparoscopic electrocoagulation of the ovarian surface seems to be lower than after ovarian wedge resection; it can be reduced by abdominal lavage and artificial ascites.
The current study tested the effects of following the child's attentional lead on the efficiency of object-label teaching. Three preschoolers with mental retardation participated. An alternating-treatments design was used to test relative treatment effects. An elicited-production method of teaching object labels was used to present the words under two conditions. Two sets of 32 nonsense words and unfamiliar objects were randomly assigned to the two teaching conditions to create equivalent goal sets and to control for prior exposure to the words and objects. Under the "following-the-child's-lead" condition, teaching episodes occurred only when the child had sustained attention to a target object or intentionally communicated about the target object. Under the "recruiting-the-child's-attention" condition, the child's attention was recruited intrusively away from his or her object of interest and toward the target object before each teaching episode began. The number of teaching trials per item and per session was carefully controlled. Results indicated that object-label teaching was more efficient under the following-the-child's-lead condition for all three participants.
Thirty-eight cases of Hodgkin's disease (HD, lymphocyte-predominant, n = 10; nodular sclerosis, n = 10; mixed cellularity, n = 10; lymphocyte depletion, n = 8) were investigated with the antibody PC10 directed against the proliferating cell nuclear antigen (PCNA) with B- and T-cell markers using a double-staining technique in paraffin-embedded material. It could be shown that nearly all (95-97%) Hodgkin's and Reed-Sternberg (HRS) cells and their variants were PCNA-positive regardless of the type of HD. There was only a low number of PCNA-positive lymphocytes (2.8-3.4%) in all types mostly consisting of MT1-positive T lymphocytes. In contrast to the other types, lymphocyte-predominant type showed a relatively high percentage (5%) of Leu-7-positive lymphocytes. The high percentage of PCNA-positive HRS cells correlates with their malignant nature, and might be another example of dysregulated expression of PCNA.
Using a sequential double-immunostaining technique, a morphometric analysis was performed on routinely processed bone marrow trephines from 20 patients with secondary (reactive) polycythaemia and 28 patients with polycythaemia rubra vera to determine the proliferation capacity of erythropoiesis. Monoclonal antibodies PC10--anti-proliferating cell nuclear antigen (PCNA)--and Ret40f--anti-glycophorin C--were employed. For comparison with the PCNA-labelling index, in a pilot study, Ki-67 was additionally used on frozen-section material. In comparison with normal bone marrow (15 patients) morphometric and statistical evaluation revealed a numerical increase in erythroid precursors (pro-, erythro- and normoblasts) in secondary polycythaemia and to a pronounced degree in polycythaemia rubra vera. In comparison with secondary polycythaemia and the control group, in polycythaemia rubra vera there was a significant enhancement of proliferation according to PCNA-staining reactivity in all haematopoietic cell elements and particularly in the erythroid series. Evaluation of PCNA v. Ki-67 immunostaining disclosed only a slight difference, which could be mainly attributed to various modalities of antigen expression during the cell cycle. Our findings are in keeping with in vitro studies on cultured erythroid progenitor cells and, in problematic cases, may present a valuable aid in differentiation between reactive lesions and polycythaemia rubra vera.
To analyse the cytological features of benign monocytoid B-cells, we investigated, histologically and immunohistochemically, 78 reactive lymphadenopathies expressing monocytoid B-cell reactions. Within a broad cytological spectrum of reactive monocytoid B-cells, two cytological types can be recognized: 1 the common type composed of medium-sized cells with irregular or bean-shaped nuclei and inconspicuous nucleoli, and 2 the large cell type composed of cells considered to represent large transformed monocytoid B-cells, with less pleomorphic round nuclei with vesicular chromatin and moderately basophilic, prominent nucleoli. In between these variants transitional forms showing evolution to large transformed monocytoid B-cells occurred. While monocytoid B-cell reactions in 70.5% of all cases were composed predominantly of the common type of monocytoid B-cells, in 29.5% of cases the large transformed cells prevailed. The two distinctive cytological types of reactive monocytoid B-cells seem to have their neoplastic counterparts in monocytoid B-cell lymphoma, including its large cell variant.