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Biomedical subjects

D Ofner

Publications and source records attributed to D Ofner.

At least 91 records · Page 5Linked to original sources
PubMed1992

Immunohistochemical demonstration of chromogranins A and B in neuroendocrine tumors of the lung.

Fifty neuroendocrine tumors of the lung (16 carcinoids, two atypical carcinoids/well-differentiated neuroendocrine carcinomas [WDNCs], 13 neuroendocrine carcinomas of intermediate cell type [SCNCs], and 19 neuroendocrine carcinomas of small cell type [SCNs]) were immunohistochemically investigated with antibodies against chromogranins A and B. All carcinoids and WDNCs were positive for both chromogranins A and B, whereas in cases of ICNC and SCNC both markers were only expressed in six and five cases, respectively. One ICNC was only positive for chromogranin A. In cases of SCNC five tumors were exclusively positive for chromogranin A and six were positive only for chromogranin B. Chromogranins are therefore excellent markers for the immunohistochemical demonstration of carcinoids and WDNCs. It may be speculated that expression of chromogranins in cases of ICNC and SCNC represents a higher degree of differentiation in these tumors.

Carcinoid Tumor↗
PubMed1992

Deoxyribonucleic acid flow cytometry and semiquantitative histology of spermatogenesis: a comparative study.

OBJECTIVE: To compare deoxyribonucleic acid (DNA) flow cytometry with a semiquantitative histologic method for the assessment of spermatogenesis and to investigate the influence of various preparative techniques on the results of DNA measurements. DESIGN: Testicular tissue from 52 autopsies was examined for spermatogenesis by DNA flow cytometry and by conventional semiquantitative histology. Flow cytometry was performed on single nuclei suspensions from fine needle aspiration biopsies, resuspended imprints, as well as on specimens obtained by mechanical disaggregation of surgical biopsies of the same testis. RESULTS: In all cases, flow cytometry revealed a characteristic distribution pattern of haploid (n), diploid (2n), and tetraploid (4n) cells independent of the preparation technique used. The percentage of haploid cells of the testes showed statistically highly significant correlations (P = 0.0002) with the results of semiquantitative histology. Fine needle aspiration biopsy always contained more haploid cells compared with resuspended imprints and mechanically disaggregated samples. CONCLUSION: Our results confirm the suitability of DNA flow cytometry as a fast and reliable quantitative method for the assessment of spermatogenesis and demonstrate its optimal feasibility in combination with fine needle aspiration biopsy.

Adult↗
PubMed1992

Relationship between quantity of silver stained nucleolar organizer regions associated proteins (Ag-NORs) and population doubling time in ten breast cancer cell lines.

Using a one-step silver staining technique ten human breast cancer cell lines were investigated, determining by means of automated image analysis the mean area of Ag-NORs per nucleus, the total number of Ag-NORs, and the so-called "scattered" and "clustered" Ag-NORs. These parameters were statistically correlated with the population doubling time (PDT) of the various carcinoma cell lines of this series. Our results show that the mean area of Ag-NORs per nucleus (p less than 0.001) is highly significantly correlated to the PDT, whereas all other parameters were less or not significant. It is concluded that the assessment of the area of Ag-NORs by automated image analysis is a simple and reliable method for the determination of cell duplication rates.

Breast Neoplasms↗
PubMed1992

Classic, atypical, and anaplastic meningioma: three histopathological subtypes of clinical relevance.

This study correlates the histopathological classification of meningiomas with clinicopathological features of biological activity. A retrospective evaluation of 1799 surgical specimens of meningiomas from 1582 patients was made. The classic histopathological type, atypical meningiomas defined by increased cellularity and at least five mitotic figures in 10 high-power fields, anaplastic (malignant) meningiomas, and hemangiopericytic or papillary meningiomas were seen in 87.6%, 7.2%, 2.4%, and 2.8% of operations, respectively. The rates of recurrence in surgically treated patients with classic, atypical, anaplastic, and hemangiopericytic or papillary meningiomas were 6.96%, 34.6%, 72.7%, and 68.2%, respectively. The extent of surgery and the tumor size and site were studied in detail in 252 tumors of all histopathological types. Recurrences were rare in classic meningiomas after complete resection, whereas atypical and anaplastic tumors recurred after complete resection much more frequently. Classic meningiomas, hemangiopericytomas, and papillary meningiomas were smaller at surgery than atypical and malignant meningiomas. Atypical and malignant tumors were operated on more often in falcine and lateral convexity regions than were classic meningiomas. To support the authors' subjective categorization by a quantitative parameter related to proliferation, 112 meningiomas comprising all histopathological subtypes were investigated for staining of argyrophilic nucleolar organizer region proteins (Ag-NOR's). The Ag-NOR counts showed significant differences between classic, atypical, and anaplastic tumors but no significant differences between primary and recurrent tumors. Hemangiopericytomas and papillary meningiomas had lower Ag-NOR values than anaplastic meningiomas. A correlation of Ag-NOR numbers with the authors' histopathological scale of malignancy supports the introduction of atypical meningiomas with intermediate biological behavior on the classification scale between classic and anaplastic meningiomas. Overlapping of Ag-NOR numbers among all groups of malignancy may restrict the prognostic value of Ag-NOR counting in the individual case.

Aged↗
PubMed1991

Does pancreas transplantation influence the course of diabetic retinopathy?

Between March 1983 and December 1989 a total of 57 pancreas transplants were performed in 54 patients, of whom 49 also received a kidney for end-stage diabetic nephropathy. Of the surviving 44 patients, 39 had regular pre-operative and post-operative ophthalmological examinations. Diabetic retinopathy was classified according to the original "Early treatment diabetic retinopathy study" (ETDRS) protocol. At the time of this analysis a total of 25 patients had a functioning pancreas transplant and 23 of them also a functioning renal allograft after a mean observation time of 43.2 months (Group 1). They were all free of exogenous insulin, HbA1c being 6.2% (5.1-6.9%; normal value 4.2-5.9%). Fourteen patients in Group 2 lost their pancreas transplant during the first four years. Six of them still have a functioning renal allograft, four patients regularly undergo hemodialysis. Mean HbA1c is 7.5% (5.7-9.2%). Before transplantation, grade of retinopathy according the ETDRS protocol was 6.7 (2-10) in group 1 patients and 7.9 (3-10) in group 2. In group 1 patients stabilisation of retinopathy was observed in 33 eyes (73.3%) and clear improvement achieved in 4 eyes (8.8%). Detoriation occurred in 8 eyes (17.7%) only. In group 2, 14 eyes (54%) remained stable, whereas progression of the disease continued in 12 eyes (46%). From these results it is concluded that the course of diabetic retinopathy is positively influenced by successful pancreas transplantation.

Adult↗
PubMed1991

Small bowel transplantation in the rat: impact of various immunosuppressive regimens on graft-versus-host reaction.

The effect of ciclosporin (CS) and methotrexate (MTX) on the development of graft-versus-host (GvH) disease was examined after small bowel allotransplantation in the rat. The drugs were tested either alone or in combination. Lewis small bowel allografts were transplantated into Brown Norway recipients in a heterotopic position. The native small bowel, spleen, liver, skin, mesenteric lymph nodes and the kidney of the recipients were examined histologically 5, 10 and 20 days after allotransplantation. Intraepithelial lymphocyte numbers were determined quantitatively in the native small bowel. The relative spleen weight of the host was determined after sacrifice for estimation of the severity of GvH disease. Grade I GvH reaction of the native small bowel occurred in the animals without immunosuppression, but graft rejection predominated in this group. Treatment with CS was effective in the early postoperative periods; after 10 and 20 days GvH lesions in the native small bowel were comparable to those observed in the allogeneic combinations. MTX had a detrimental effect on the allografts and the GvH reaction was augmented. When CS and MTX were combined, GvH lesions were comparable to those in the animals treated solely with CS. Animals, however, suffered from heavy side effects. The spleen, liver, lymph nodes and kidney exhibited only unspecific histologic changes, which could not unequivocally be recognized as a GvH reaction. This was true for all groups. As a conclusion it can be said that GvH reaction occurs in the early postoperative period in a fully allogeneic model and cannot be prevented by CS in the dosae used. MTX was not seen to be of any value in this regard.

Animals↗
PubMed1990

[Intestinal angiodysplasia as a cause of severe intestinal hemorrhage--report of 4 cases].

Angiodysplasia of the small intestine alone cannot be differentiated histologically from hereditary hemorrhagic telangiectasia (Morbus Rendu-Osler-Weber). Isolated localisation in the small intestine is rare and requires surgery in the event of massive bleeding. Four cases of bleeding from angiodysplasias of the small intestine in patients having undergone surgery at our institution over a ten-year period are presented. In three patients the particular intestine was resected. Two of these patients had an uneventful follow-up of even and ten years, one patient relapsed and was rehospitalized for surgical treatment. The fourth patient, who showed angiodysplasias scattered over the entire small intestine, had no further bleeding over a three-year period after transmural ligations of the lesions found by intraoperative endoscopical diaphany.

Adult↗
PubMed1990

Silver stained nucleolar organizer region proteins (Ag-NORs) as a predictor of prognosis in colonic cancer.

Using a one-step silver nitrate staining technique, routinely processed tumour tissues of 49 carcinomas of the colon were investigated to demonstrate silver-stained nucleoli (Ag-nus) and argyrophilic proteins associated with the so-called nucleolar organizer regions (Ag-NORs). Patients with attempted curative resections and tumour stages Dukes' A, B, C1 and C2, with an uneventful follow-up period of at least 48 months (N = 17), showed a statistically significant (P = 0.0001) lower mean number of scattered Ag-NORs (3.04; SD: 1.08) compared to patients who developed metastases during their follow-up period (N = 15; 5.40; SD: 1.28), as well as to patients who underwent palliative surgical treatment (N = 17; 4.48; SD: 1.67). Mean numbers of scattered Ag-NORs per nucleus and staging of the tumour were strongly related (P = 0.0001) to cancer-specific survival. The results indicate that the evaluation of silver-stained particles according to their different distribution patterns is of great value with regard to the clinical outcome of colonic carcinoma and may even allow a more accurate prognostic assessment of these patients than the WHO grading system, UICC staging system, the so-called Jass-scoring system, and Dukes' classification.

Adult↗
PubMed1990

Argyrophilic nucleolar organizer region proteins (Ag-NORs) in human brain tumors: relations with grade of malignancy and proliferation indices.

Proliferation indices and mean number of silver-stained nucleolar organizer region-associated proteins (Ag-NORs) are compared in 65 brain tumors, including 34 gliomas, 8 meningiomas, 17 metastatic tumors, and 6 other tumors. Immunocytochemical investigations include labeling with the monoclonal antibody Ki-67 which identifies the whole growth fraction, and with a monoclonal antibody against bromodeoxyuridine (BrdUrd) which detects cells in the S phase of the cell cycle after in vitro incubation with BrdUrd. When all types of tumors are collectively considered, mean numbers of Ag-NORs did not correlate with Ki-67 and Brd-Urd labeling indices (LIs) and mitotic index. Among tumor subtypes, only meningiomas showed significant correlations between Ag-NOR counts, LIs, and malignancy. Mean number of Ag-NORs did not correlate with proliferation indices and tumor grade in low-grade and high-grade gliomas. However, recurrent high-grade gliomas showed a tendency to higher Ag-NOR counts than primary tumors. This study indicates that counting of Ag-NORs in paraffin sections is of limited value in tumor neuropathology. Correlations found in meningeal tumors should be substantiated in larger series.

Adult↗
PubMed1990

[Permanent tracheostomy in rats].

For bronchoalveolar lavages (BAL) after lung transplantation in the rat two different tubes for creation of a permanent tracheostoma were devised and tested. Typ I was of plastic material and required closure of the trachea oral of the tube thus excluding the upper respiratory tract for breathing. All these animals deprived of their sense of smell and direction died within 50 hours despite optimal husbandry. Typ II was a T-shaped metall tube allowing normal nasal breathing. This tube was well tolerated by the animals and facilitated repeated BAL. BAL on day 3 following tracheotomy with 5% lymphocytes, 2% polymorphonuclear leukocytes and 95% alveolar macrophages was considered to be normal when compared with human findings. An increase in polymorphonuclear leucocytes and epithelial cells together with bacteria on day 6 was believed to be due to tracheobronchitis. This assumption was supported by the fact, that both cell types and the number of bacteria significantly decreased 3 days later. A steady increase of lymphocytes seems to be associated with repeated BAL.

Animals↗
PubMed1989

[The effect of donor conditioning and perioperative management of recipients on the initial and late function of kidney transplants].

On the basis of 88 consecutive cadaveric renal transplants, multiple variables concerning donor conditioning and perioperative recipient management which may have an influence on the occurrence of acute tubular necrosis (ATN), were analysed and their impact on long-term results assessed. Cold ischaemia time turned out to be the greatest risk factor and was seven hours shorter in patients with good initial function when compared with patients with ATN. Although actual one-year graft survival was similar in both groups, the postoperative course was more complicated in the ATN group and management more onerous. Furthermore, two patients of the initial non-function group died of complications directly related to renal replacement therapy. Seventeen hours cold ischaemia time was associated with more than 80% initial function. This time is sufficient to allow careful tissue typing and organ transportation.

Acute Kidney Injury↗