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Biomedical subjects

D Trpinac

Publications and source records attributed to D Trpinac.

8 recordsLinked to original sources
PubMed1998

Correlations between mitotic and apoptotic indices, number of interphase NORs, and histological grading in squamous cell lung cancer.

Proliferative activity of tumors is strongly associated with prognosis and response to therapy. The reason for faster and uncontrolled growth rate of tumors compared with normal tissue may be caused by the greater proliferation of cells, the smaller rate of cell death, or both. Cell production vs. cell loss rates, and their correlation with a grade of tumor cell differentiation (G) was estimated in 45 cases of squamous cell lung cancers (SCLC) by the use of mitotic indices (MI), number of interphase NORs, and apoptotic indices (AI) as parameters. The mitotic figures as well as apoptotic cells were observed on paraffin sections (4-microm thick) stained with haematoxylin and eosin, and with Feulgen reaction with Schiff-type reagent containing 0.5% Toluidine Blue. According to our results, all three parameters distinguish significantly (P < 0.05) between well and moderately or poorly differentiated groups, but not between the first two groups, and clearly discriminate between low- and high-grade malignancy. These results suggest classification of squamous cell lung cancers into two groups, a group of low and a group of high proliferative activity, despite their morphological appearance. Regression analysis revealed a significant (P < 0.0005) correlation between MI and AgNOR counts per cell nucleus as proliferative markers and AI as a marker of cell loss. The number of mitoses and apoptoses, especially when they are expressed as a percentage of the total number of tumor cells, are markers of tumor proliferation rate. They both can be used in biofunctional staging, based on cell kinetics, to provide more prognostic information about lung cancers than clinicopathological staging.

Adult↗
PubMed1998

The acidophilic nature of neuronal Golgi impregnation.

The mechanisms of Golgi impregnation of neurons has remained enigmatic for decades. Recently, it was suggested that divalent (di)chromate anions play a role in the Golgi impregnation process. Therefore, we incubated slices of (para)formaldehyde-fixed rat brain tissue in solutions of potassium (di)chromate, phosphate, chloride or nitrate at pH 6 or 7. Slices were then immersed in solutions of silver nitrate and processed for light microscopical analysis. At pH 6, dichromate probes resulted in dense and homogeneous impregnation of neuronal cytoplasm (typical impregnation). At pH 7, chromate probes showed solely partial cytoplasmic and heavy nuclear-region neuron impregnation (atypical impregnation). Phosphate probes at pH 6 resulted in typical impregnation, whereas at pH 7 phosphate probes gave atypical impregnation. Both at pH 6 and 7, chloride and nitrate probes did not yield any Golgi impregnation. These findings confirmed the pH-dependence of silver-chromate Golgi impregnation as well as the correctness of corresponding acidic silver-phosphate impregnation. Our study revealed a previously unknown, strong anion-dependence of Golgi impregnation, suggesting that hydrogenated monovalent anions are carriers of the neuron impregnation.

Animals↗
PubMed1992

Myocardial bridges over coronary arteries in Cercopithecus.

The presence of myocardial bridges over the coronary arteries has been studied in 29 monkey (Cercopithecus aethiops) hearts. The great resemblance between the Cercopithecus subepicardial arterial net with the corresponding one in humans has been revealed. There is a high incidence (83%) of myocardial bridges only over the ventricular branches of both coronary arteries. Myocardial bridges are usually (90%) located over the left coronary artery branches, and the left anterior interventricular branch is the most frequently (69%) overbridged vessel. The bridges are always single over the vessel examined and their length varies from 0.5 mm to 31.6 mm. No statistically significant sexual difference in myocardial bridges distribution is reported.

Animals↗
PubMed1990

[Origin of mature granulocytes in the active phase and in remission in various types of acute leukemias].

The problem of provenance of the mature granulocytes in acute myeloblastic leukemia (AML) and in acute lymphoblastic leukemia in their active phase and in remission is still completely unresolved. Mature granulocytes could possibly arise in acute phase of AML from the remaining normal möelopoietic or granulopoietic stem cell or from the very leukemic clone of stem cell which still display, at least partially, the ability to sustain maturation to normal granulocyte level. In ALL, mature granulocyte probably arise from normal granulocyte precursors. In remitted AML, according to opinions of a majority of authors, mature neutrophils descend from normal stem cells. Following the study of 19 patients with AML and 19 patients with ALL, by utilizing the morphological, cytochemical and cytoenzymic properties of granulocytes et the light and electronomicroscopic level the authors have concluded: (1) in comparison with normal granulocytes, granulocytes show in the active AML, hypogranularity as well as a decrease in the activity of all studied enzymes (myeloperoxidase, alkaline and acidic phosphatase and the esterases). (2) In ALL, mature granulocytes do not feature any particular differences in the above pattern as compared with normal granulocytes. (3) In AML remission, the difference between the mature granulocytes and the granulocytes in the active disease is rather slight as compared with the morphological, cytochemical an cytonzymic characteristics. The authors conclude that in a number of patients with AML and in the remitted patients mature granulocytes could possibly originate from the leukemic stem cells which acquired the ability to respond to normal CSF by manner of the gross destruction of the leukemic tumour mass.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMedDate not supplied

[Changes in peritoneal mesothelial cells in patients on peritoneal dialysis].

INTRODUCTION: Some thirty years ago peritoneal dialysis (PD) became a respectable modality of renal replacement therapy. That is why peritoneal membrane attracted interest of investigators. Certain changes, known as uremic serositis, appear in morphology of serous membranes in end stage kidney disease (ESKD). The aim of our investigation was to examine the morphology of peritoneal lining cells in control group of healthy persons and morphology of peritoneal lining cells in patients on PD. MATERIAL AND METHODS: Peritoneal biopsies were taken in 10 healthy volunteers during the kidney donation and in 15 patients on PD during clinically indicated extirpation. Biopsy samples were prepared for standard routine HE staining and for plastic embedded fine sections studying. Sections were mounted in an ultramicrotome, stained with Toluidine blue (TB) and studied by light microscope (SM), while fine sections were mounted in an ultramicrotome and studied by transmission electron microscope (TEM). RESULTS: One layer mesothelium of the cuboidal or flattened lining cells were present over the lamina propria connective tissue. Mesothelial cells were overlapped like tiles on the roof. These cells were interconnected with different types of cell junctions (unpermeable, adhesion and communication junctions) positioned on lateral parts of the interdigitated cell membranes. A great number of microvilli were often present on the appical surface, as well as a kinocilia and lamellar bodies. Nuclei were euchromatic with well developed nucleoli. Many ribosomes, mitochondria, cisternae of rough endoplasmic reticulum (RER) and Golgi apparatus, lamellar bodies and lipid inclusions were present in the cytoplasm. Using TEM in analyzing fine sections of biopsies of patients on PD, characteristic ultrastructural changes including epithelial defects with only remaining parts of destroyed cells were established, as well as significantly greater number of rough endoplasmic reticulum (RER) cisternae and immature mesothelial cells in lamina propria indicating intensive regeneration of this epithelium. The cytoplasm of new mesothelial cells were of less electron density on TEM photomicrographs, whereas the nuclei of mesothelial cells in these patients were euchromatic with prominent nucleoli and numerous perichromatic granules and fibrogranular nuclear bodies, indicating cells of great activity. Cytoplasmic protrusions of different shape and content were often recognized on the apical surface of cells. Lamellar bodies were also present in this group of patients within the mesothelial cells, as well as between two mesothelial cells or on their apical surface. Mitochondria were picnotic in many of the mesothelial cells of peritoneum in this patient group. In these mesothelial cells intracytoplasmic paracrystaline inclusions were established. TEM photomicrographs showed basal lamina multiplication in this epithelium. CONCLUSION: Our findings comply with reports of other authors. It should be stressed that TEM examination detects characteristic ultrastructural changes in mesothelial lining cells of peritoneum in patients on PD, which could compromise the function of peritoneum as a membrane for dialysis.

Epithelium↗
PubMedDate not supplied

[Pseudothrombocytes in acute leukemias].

Pseudoplatelets are the cytoplasmic fragments in the size of platelets originated not from megakaryocytes but from other blood cells which were observed in some patients with leukemia and infection. The clinical importance of pseudoplatelets is manifested in the falsely increased number of platelets in these patients. Transmission electron microscopy was used in the cytologic examination of 23 patients with different types of acute leukemia. The presence of pseudoplatelets in the form of budding of the cytoplasm of the granulocytic, monocytic and lymphocytic strains of various maturity has been shown.

Acute Disease↗