Biomedical subjects

O Doğan

Publications and source records attributed to O Doğan.

5 recordsLinked to original sources

PubMed1995

A sensitive staining method for NORs.

A sensitive staining method for nucleolar organizer regions (NORs) is described, using blue toning of AgNORs. NORs are loops of DNA which are transcribed into ribosomal RNA. NORs can be demonstrated by staining with silver nitrate, since NOR-associated proteins are argyrophilic, producing structures termed AgNORs. Normal blood lymphocytes were stained with both methods. The number and resolution of NORs increased 2-3 times by blue toning (30 mmol/l FeCl3, 11 mmol/l potassium hexacyanoferrate(III), and 33 mmol/l oxalic acid) compared with silver staining. A significant difference in the number of NORs was noticed between silver-stained and blue-toned cells (P < 0.001). The blue toning technique thus appears to be more sensitive in detecting NORs than the AgNOR method and may prove a useful alternative for applications in histopathology.

Chlorides↗

PubMed1993

Nucleolar organizing regions in the operated rat stomach: relationship to metaplasia, dysplasia and carcinoma.

This study investigated the role of duodenogastric reflux in rats after antecolic gastrojejunostomy. At the end of the study, adenocarcinoma was present in 43 per cent, dysplasia in 14 per cent and intestinal metaplasia in 43 per cent of animals. No such changes were found in control rats. A technique for silver staining nucleolar organizing regions (AgNORs) was applied to these lesions and to the control group. The AgNOR count gradually increased from normal gastric mucosa to carcinoma. This technique demonstrated differences in AgNOR count between normal mucosa and other lesions (adenocarcinoma, dysplasia, intestinal metaplasia) (P < 0.001). There was, however, considerable overlap among adenocarcinoma, dysplasia and metaplasia (P > 0.1).

Animals↗

PubMed1992

Nucleolar organizer regions in pituitary gland adenomas.

Nucleolar organizer regions are DNA segments concerned with the synthesis of ribosomal RNA (rRNA). Some specific proteins related to NORs can be demonstrated by a silver technique and are then referred to as Ag-NORs. The mean number of Ag-NORs per cell has been used as a marker of cell proliferation in recent years and there is some evidence to suggest that Ag-NOR counts can be used to differentiate between normal and neoplastic cells. Paraffin block sections of 42 pituitary gland adenomas and 24 normal adult pituitary glands have been examined using the Ag-NOR staining technique. Touch imprints of nine adenomas and 12 normal adult pituitary glands were also examined using the same Ag-NOR staining technique. Using light microscopy at x2000 magnification, the Ag-NORs were located as black dots in the cell nuclei and the mean number of Ag-NORs per cell was determined. No significant difference was observed between blocked sections and imprints of adenomas or between imprints and paraffin sections of normal glands. However, a significant difference was observed between the mean number of Ag-NORs in pituitary gland adenomas and normal glands in paraffin block sections and touch preparations (P less than 0.001). The modified Ag-NOR technique can be a useful aid in the differential diagnosis between normal pituitary gland tissue and pituitary adenomas, especially during surgical operations.

Adenoma↗

PubMed1990

[Investigation of the microbiological variations at the empty root canals after retrograde histoacryl filling that is made with pulpectomy at the same time].

Many researchers defended the thesis of eradicating the apical foramen microleakage for a successful root canal treatment. This study has been designed to defect whether microorganisms will grow or not at the empty root canals as a result of the perfect obstruction of the apical foramen with histoacryl of least microleakage retrogradely. The study has been realized on 24 teeth of 6 adult dogs. Histoacryl was used to obstruct the apical foramens and the experimental animals were anesthetized with general anesthesia. Experimental animals were divided into three groups before the operation. At each group, eight teeth of two experimental animals were studied on. Consequently, a great amount of streptococcus kind, lactobacillus and staphylococcus were isolated at the cultures taken from the root canals of 15 days cases. At 30 day cases, peptostreptococus, lacto bacillus and staphylococcus were isolated while at 60 day cases streptococcus pneumonia, and lactobacillus were isolated and evaluated as meaningless.

Animals↗

PubMedDate not supplied

Pericardial mesothelioma. A pediatric case report.

A nine and a half year old boy was brought to the hospital because of a cough, dyspnea and mild fever. He was well-nourished and had an uneventful history. His chest X-ray and electrocardiographic findings suggested pericarditis but further examinations and an open pericardial biopsy revealed a mass histologically diagnosed as pericardial mesothelioma, a very rare tumor in this age group.

Child↗