Search PubMed⌕ Search

Biomedical subjects

D Ofner

Publications and source records attributed to D Ofner.

At least 55 records · Page 3Linked to original sources
PubMed1995

Pentoxifylline as an adjunct to cyclosporine-based immunosuppression does not improve the outcome of renal transplantation.

The adjunct of PTX to the therapeutic regimen after renal transplantation had no effect on the incidence of ATN, immunologic or infectious complications, or CyA toxicity. Also, patient and graft survival was not affected. The four deaths in the study group can probably not be attributed to PTX therapy. From these data it is concluded that PTX is not able to improve the outcome of renal transplantation.

Adult↗
PubMed1994

In vitro investigations of interphase and metaphase argyrophilic nucleolar organizer regions and cellular proliferation in the human urothelial cancer cell line HOK-1.

Detailed investigation of cell growth and nucleolar organizer region associated argyrophilic proteins (Ag-NORs) is necessary to assess a possible impact of Ag-NOR quantification on the diagnosis and prognosis of tumours. In this study, cellular proliferation of the transitional-cell carcinoma cell line HOK-1 was modulated over a period of 11 days by starvation and subsequent medium addition. Proliferation was determined daily by DNA flow cytometric estimation of S-phase fraction (SPF) and mitotic index (MI) calculation. The number and area of interphase Ag-NORs were quantified by automated image analysis daily and the number of Ag-NOR bearing chromosomes in metaphase was counted. In interphase nuclei, Ag-NOR area showed a highly significant correlation with SPF (p < 0.0001) whereas interphase Ag-NOR number showed significant correlation with MI (p < 0.05). A positive relationship between the number of Ag-NOR bearing chromosomes in metaphases and cellular proliferation was also observed. There is variability in Ag-NOR quantity during interphase and metaphase depending on growth conditions in vitro. Correlations of the number of interphase Ag-NORs with the MI on one hand and Ag-NOR area with SPF on the other provide further evidence that distribution and quantity of Ag-NORs are strongly influenced by the cell cycle phase within the structural-functional unit of the nucleolus.

Carcinoma, Transitional Cell↗
PubMed1994

Immunohistochemical metallothionein expression in colorectal adenocarcinoma: correlation with tumour stage and patient survival.

Metallothioneins (MTs), a set of ubiquitous low-molecular-weight proteins essential for the protection of cells against heavy metal ion toxicity, were demonstrated immunohistochemically using a monoclonal antibody (E9) against a conserved epitope of I and II isoforms in a series of 109 colorectal adenocarcinomas. In a semiquantitative analysis strong MT expression in the majority of tumour cells was observed in 34 (31%) cases, 24 (22%) tumours showed a focal MT positivity, and 51 (47%) almost completely lacked MT expression. These differences in MT expression were statistically significantly (P < 0.05) associated with the tumour stage (Dukes classification) and the lymph node involvement at the time of operation (pN stages). However, in contrast to previous findings obtained on a variety of tumours, MT positivity was associated with a favourable clinical outcome in colonic carcinoma, which may indicate their different biological behaviour. Survival curves of cases with MT-positive and MT-negative status differed from each other in a univariate analysis (Mantel-Haenszel: 8.9, P < 0.05) but lost significance when a multivariate analysis was carried out by means of the Cox proportional regression model with Dukes' stages as a stratification factor. It is concluded that immunohistochemically demonstrated MT expression is significantly associated with tumour stages but does not represent an independent prognostic variable in colorectal cancer. However, it may provide important information about some of the biological mechanisms underlying progression in colorectal cancer.

Adenocarcinoma↗
PubMed1994

Myoelectric activity during small bowel allograft rejection.

The effect of rejection on myoelectric activity of an orthotopically transplanted small intestinal segment (group I, N = 14) was studied. Electrodes were placed on grafts and recipient small bowel. Isografts (group II, N = 5) and native bowel (group III, N = 5) served as controls. The first morphological signs of rejection were seen on day 6 and steadily progressed until day 11, when the cellular infiltrate involved all layers of the bowel wall. Slow-wave frequencies remained unchanged throughout the observation period. No difference was detectable between grafts (group I: 31.9 +/- 1.65; group II: 31.36 +/- 0.7) and native bowel after transection (group I: 32.16 +/- 1.78; group II: 31.50 +/- 1.01), which was different (P = 0.0001) from intact bowel of group III animals (38.4 +/- 0.81). Irregular MMCs were detectable in grafts from day 5 on and replaced after food intake by random spiking activities. At day 8, spiking activities disappeared in allografts, which showed a still preserved mucosal architecture, while slow-wave activities continued. These findings demonstrate that intestinal allografts during rejection develop paralysis before mucosal destruction is established, which might be of clinical relevance.

Action Potentials↗
PubMed1994

Early diagnosis of fat embolism syndrome by automated image analysis of alveolar macrophages.

To evaluate the value of automated semiquantitative analysis of fat within alveolar macrophages as an early diagnostic tool for fat embolism syndrome (FES), we investigated 3 patients with respiratory failure following long-bone fractures. The mean area of fat droplets per alveolar macrophage was determined in pixels and, additionally, the percentage of the evaluated areas was calculated. In 2 patients, the diagnosis of FES could be established as early as 24 hr after trauma. Both patients showed an increase in the area of fat per alveolar macrophage (pixels: 851, 1069) as well as in the percentage of fat area per alveolar macrophage area (40.04%, 52.73%), whereas the analysis of the bronchoalveolar lavage (BAL) specimens of a third patient, who later recovered without appearance of clinical signs of FES, revealed only minimal fat content (pixels: 82; 3.82%). Automated semiquantitative analysis of fat within alveolar macrophages may be helpful in the early diagnosis of FES.

Embolism, Fat↗
PubMed1994

[A standardized AgNOR stain method for formalin fixed and paraffin embedded material].

Visualization of proteins associated with nucleolar organizer regions proteins (AgNORs) on formalin-fixed and paraffin-embedded archival tissues is substantially improved after application of wet autoclave pretreatment. Silver staining results are comparable to those obtained on tissues processed in alcohol based fixatives, illustrating AgNORs as substructures of the nucleoli without any staining artefacts. A highly reproducible staining quality was achieved irrespective of tissue origin or duration of formalin fixation. As a result of this novel and simple method, the grounds have been prepared for standardized AgNOR quantification on archival material.

Fixatives↗
PubMed1994

[Moist autoclaving. A simplified method for antigen unmasking].

Wet autoclaving is a simple, reliable and time-effective method for antigen retrieval in routinely processed archival material. Both routine diagnostic (e.g., oestrogen and progesterone receptors, cytoskeletal proteins) and research antibodies (e.g. various p53 antibodies, mdm-2, bcl-2, MIB-1) are reported to demonstrate its application. We autoclaving may allow successful application of antibodies in paraffin-embedded tissues designed for use on frozen sections. The technique has the potential to reliably handle up to 200 sections at a time, without evidence of any significant damage to the sections or nuclear morphology.

Antigens, Neoplasm↗
PubMed1994

Deep penetrating dermatofibroma versus dermatofibrosarcoma protuberans. A clinicopathologic comparison.

A study of the clinical, histological, and immunohistochemical features of 20 cases of deep penetrating dermatofibroma (DPDF) and eight cases with 14 specimens (eight primary, one reexcision, five secondary tumors) of dermatofibrosarcoma protuberans (DFSP) showed distinct entities. Clinically, DPDF usually appeared as a nodule (approximately 2 cm) of the (lower) limbs, whereas DFSP affected the trunk (shoulder) with irregularly arranged plaques or nodules (> 5 cm). Histologically, DPDF showed a regular silhouette with a smooth, nodular (four of 20) or scalloped (16 of 20) lower margin and variable sclerosis (nine of 20); DFSP, irregularly infiltrated fatty tissue in a lacelike/honeycomb (eight of 14), multilayered (three of 14), or mixed pattern (three of 14), but without sclerosis. Immunohistochemically, DPDF was mostly negative with QBEnd 10 (CD34; 18 of 20) but positive for factor XIIIa (17 of 20), actin (HHF35; 10 of 20), and metallothionein (MT; 12 of 20). DFSP was positive for CD34 (13 of 14), yet with some sparing of central tumor parts, highly cellular tumor nodules, and myxoid areas; factor XIIIa and MT were consistently negative, as was HHF35 in 11 of 14 cases. In a multivariate analysis of histologic and immunohistochemical criteria, the combination of sclerosis and labeling with MT was most valid (p = 0.0001) for diagnosis: all DPDF showed either labeling with MT in "early" (metabolically active) lesions or sclerosis in "late" lesions, not present in DFSP.

Adult↗
PubMed1994

Apolipoprotein(a) phenotype-associated decrease in lipoprotein(a) plasma concentrations after renal transplantation.

High lipoprotein(a) [Lp(a)] plasma concentrations are an independent risk factor for atherosclerosis. In the general population, Lp(a) levels are primarily determined by allelic variation at the apolipoprotein(a) [apo(a)] gene locus. Apo(a) isoforms of various sizes are associated with different Lp(a) concentrations. Patients with end-stage renal disease (ESRD) have elevated plasma concentrations of Lp(a), which are not explained by the size variation at the apo(a) gene locus. To further investigate the origin of the elevated Lp(a) plasma concentrations, we examined Lp(a) concentrations and apo(a) phenotypes in 154 ESRD patients undergoing renal transplantation. In a prospective longitudinal study we observed a rapid normalization of Lp(a) levels from an average concentration of 25.9 +/- 28.7 mg/dL before to 17.9 +/- 25.5 mg/dL 3 weeks after renal transplantation (P < .0001). Only patients with high-molecular-weight phenotypes had a significant decrease in Lp(a) plasma concentrations. This study demonstrates the nongenetic origin of elevated Lp(a) concentrations in ESRD patients, which is obviously caused by the disease. It further confirms a phenotype-associated elevation of Lp(a) concentrations in ESRD.

Adolescent↗
PubMed1994

Bronchoalveolar lavage: results of sequential, selective techniques in viable murines.

The purpose of this study was to develop an optimal technique for performing sequential bronchoalveolar lavage (BAL) in a murine animal model. Two general anesthetic regimens and four operative techniques of BAL were tested. Anesthesia by intraperitoneal injection of ketamine hydrochloride (100 mg/kg body wt) resulted in death for four of ten subjects, whereas inhalation of diethyl ether led to death for one of ten subjects. BAL using a balloon catheter under bronchoscopic guidance was comparable with postmortal lavage, tolerated better, and resulted in superior cell retrieval with respect to cell differential (macrophages: 95 +/- 2.3; lymphocytes: 3 +/- 1.2; polymorphonuclear lymphocytes [PNL]: 1.2 +/- 1.4) compared with two other techniques using a bent metal tube/polyethylene tubing combination (macrophages: 19.3 +/- 27.4; lymphocytes: 3.8 +/- 4.3; PNL: 35.5 +/- 35.5) and a bronchoscope/polyethylene tubing combination (macrophages: 11.1 +/- 25.5; lymphocytes: 0.7 +/- 1.0; PNL: 55.8 +/- 41.0). The BAL fluid contained significantly more alveolar macrophages and fewer PNL and epithelial cells (p = 0.0001, p = 0.0025, p = 0.02, respectively). We conclude that the technique using a balloon catheter under bronchoscopic guidance during inhalation of diethyl ether is the procedure of choice and results in a representative sample of BAL.

Anesthesia↗
PubMed1994

Sequential quantification of AgNOR area and number during silver staining by means of an image analysing system.

Standardized AgNOR staining protocols are required to compare results obtained by means of image analysis systems (IAS) in different laboratories. In order to investigate the staining kinetics of the NOR silver staining, we evaluated automatically the area and number of AgNORs of a human transitional-cell carcinoma cell line (HOK-1) by IAS at one minute intervals over a total staining period of 30 minutes. Results showed a constant increase (standard error of estimate: 0.001; R squared: 0.8) of the AgNOR area reaching a plateau after 10 minutes followed by further area increase. In contrast, in all experiments a pronounced variability in the AgNOR number (standard error of estimate: 0.042; R squared: 0.75) was noted, reflecting the aggregation of silver stained spots. Thus the evaluation of the AgNOR area yielded reliable and easily reproducible results, whereas the assessment of the AgNOR number by means of an automated IAS was associated with a marked variability.

Autoanalysis↗
PubMed1994

Wet autoclave pretreatment improves the visualization of silver-stained nucleolar organizer-region-associated proteins in routinely formalin-fixed and paraffin-embedded tissues.

This study describes the effect of wet autoclave pretreatment of routinely formalin-fixed and paraffin-embedded tissues on silver-stained nucleolar organizer-region-associated proteins (AgNORs) staining. The treatment of sections at superheated steam temperature (120 degrees C) before silver incubation leads to a significantly better discrimination of single-interphase AgNORs. Counting "black dots" both by eye and by means of a computer-aided image-analyzing system revealed considerably higher AgNOR mean numbers per nucleus in all pretreated cases when compared with the respective untreated controls. However, mean AgNOR numbers increased after autoclave pretreatment in a nonlinear manner (pairwise comparison by means of Spearman's Rank correlation coefficient: rho = 0.5), whereas measurement of the AgNOR area was less influenced by autoclave pretreatment (rho = 0.8). It is concluded that wet autoclave pretreatment of routinely formalin-fixed and paraffin-embedded archival material should be applied before AgNOR staining, particularly when quantitation of AgNORs involves counting procedures.

Adenocarcinoma↗