[Primary liposarcoma of bone]. / Primarni liposarkom kosti.

A case of 75-year-old man with extremely rare primary liposarcoma of the bone was presented. Stains for lipid, Sudan III, Sudan IV, and Oil Red "O", demonstrated the presence of intracellular lipid in the lipoblasts. Similarly, the S-100 immunoreactivity and electron microscopic findings of tumor cells confirmed the diagnosis of liposarcoma. Histochemical stains for PAS, Alcian-blue, mucikarmin, Toluidin-blue and Coloidal Iron were negative.

[Experimental study of the pathogenesis of frostbite. Part II. Role of the sympathetic-adrenergic system in tissue reperfusion immediately after thawing]. / Eksperimentalno istrazivanje patogeneze smrzotina--II deo. Uloga simpaticko-adrenergickog sistema u reperfusiji tkiva neposredno po odmrzavanju.

The authors have investigated the role of sympathetic-adrenergic system in reperfusion of muscular tissue of the feet of Wistar rats immediately after thawing using alpha adrenergic blocker phentolamine methanesulfonate (Regitin). Cryoinjury was applied over an experimental model of local, controlled freezing of different intensity for certain experimental groups. Blood flow through microcirculation was measured by scintigraphy, following Tc-99m-pertechnetate clearance that was given in muscular mass of frozen right, as well as unfrozen left feet of rats. Results obtained in some experimental groups were compared mutually, as well as with the control group that was not exposed to cryoinjury. The investigations have revealed that immediately after thawing existed significant reduction, non-dependent of the intensity of freezing, in blood flow in microcirculation of both frozen and unfrozen feet of rats compared to the control group. Significant increase of microcirculatory blood flow in unfrozen feet was caused by blockade of sympathetic-adrenergic system, while the blood flow remained unchanged in the frozen ones. The reduction of blood flow in microcirculation of frozen tissues immediately after thawing was not associated with sympathetic-adrenergic factor.

Estimation of chronic hepatitis C activity based on ultrastructural changes of hepatocytes.

Seventy four liver bioptic specimens of 66 patients with chronic hepatitis C were analyzed ultrastructurally and by light microscopy. According to histological activity of the disease, the patients were divided in groups with minimal activity (CPHa), mild activity (CPHb-CAHa), and moderate and severe activity (CAHb,c), respectively. The presence of lamelar, simple and complex lipid inclusions in the cytoplasm, as well as the presence of nuclear bodies and morphology of the nucleolus were analyzed by classic methods of transmission electron microscopy. Cytoplasmic lamelar inclusions were found in 84.6% of patients, and simple and complex lipid inclusions were noted in 85.1% of patients, without the differences related to histological and enzyme activity. Unaltered nucleolus was most frequently observed in patients with minimal disease activity (84.6%), viral changed in patients with mild activity (48.4%) and synthetic active in patients with moderate and severe activity (66%). Serum aminotransferase activity was significantly higher in patients with viral changed and synthetic active nucleolus. These results can indicate that HCV induces cytopathogenic and immunologic damage of hepatocytes. The presence of virus acts as toxic agent that damages hepathocytes' metabolism, thus resulting in occurrence of cytoplasmic lamelar, simple and complex lipid inclusions, respectively. Immunologic damages occur when the virus alters cell membrane of hepatocytes.

[Experimental study of the pathogenesis of frostbite. Part III. Significance of energy status of muscle tissue in the pathogenesis of frostbite]. / Eksperimentalno istrazivanje patogeneze smrzotina--III deo. Znacaj energetskog statusa misicnog tkiva u patogenezi smrzotina.

The authors have investigated energy status of muscle tissue of the lower legs of Wistar rats subjected to freezing, as well as the dependence of ultrastructure changes in muscle tissue mitochondria on the intensity of freezing. The animals were divided into three experimental groups: two groups were exposed to cryoinjury of different intensity, while the third was the control one. Cryoinjury was applied over an experimental after thawing were taken samples of muscle tissue for the analysis of content of energy phosphates and carbohydrates' metabolites, respectively, as well as for morphometric analysis of mitochondria volume out of frozen right and unfrozen left lower legs. Results obtained from different experimental groups were compared mutually and with control group that was not exposed to cryoinjury, respectively. It was found that the freezing in muscle tissue caused hydrops degeneration of mitochondria, depletion of energy reserves, reduction of energy status and the activation of mechanism of anaerobic metabolism. All these alterations were proportional to the intensity of freezing and considerably influenced contractility function of muscle cells, causing prolonged spasm of arterioles in thawed tissue, i.e., rigor congelationis that was primarily defined as an important factor in the pathogenesis of ischemic impairment of thawed tissues.

[In vivo study of spontaneous and therapy-induced apoptosis in patients with chronic lymphocytic leukemia treated with chlorambucil]. / In vivo pracenje spontane i terapijom indukovane apoptoze kod bolesnika sa HLL lecenih hlorambucilom.

The efficiency of Chlorambucil in the induction of apoptosis was investigated in the study, and measurable apoptosis parameters were compared to the other prognostic factors with the aim of possible prediction of clinical response to the therapy in the patients with CD5 + B-cell chronic lymphocytic leukemia (B-CLL). Seven newly diagnosed patients, initially treated with daily high-doses of Chlorambucil (HD-CLB) were analyzed. Quantitative analysis of apoptosis parameters on semi-fine sections obtained from peripheral blood was performed prior and during the first five days of therapy. The level of spontaneous apoptosis (SA) was determined, as well as the maximal response by apoptosis (MAR), and the time needed to establish maximal response by apoptosis (TMAR), respectively. The results revealed that the level of SA in the studied group of patients was 11.39%-20.50%. In three patients with achieved criteria for complete remission (CR) was observed high level of SA, TMAR 2-4 days and MAR 23.42-26.36%, respectively. All patients with CR were with negative LDT, non-diffuse involvement of bone marrow and clinical stage B. Criteria for partial remission (PR) were achieved in 4 patients. Within this group, all three measurable parameters of apoptosis could have been determined in only one patient, while in the rest was noticed the increased percentage of apoptotic cells on the last day of follow-up. In all patients was observed negative LDT, diffuse bone marrow involvement, and 2 out of 4 patients had CLPL of cytomorphological type and clinical stage B. By comparing the obtained values of measurable apoptotic parameters with the clinical response to the applied therapy with HD-CLB, it is possible to divide our patients into two groups: patients who have achieved CR have the highest percentage of cells dying due to the therapy-induced apoptosis, as well as the higher values of measurable parameters compared to the certain parameters of the patients with the criteria for PR. Our preliminary results of therapeutic response to the apoptosis might be useful for the timely decision upon the duration of therapy and change of modality of treatment for every patient during the follow-up period.

[Experimental study of the pathogenesis of frostbite. Part I. Pathohistologic and ultrastructural changes in tissues immediately after thawing]. / Eksperimentalno istrazivanje patogeneze smrzotina--I deo. Patohistoloske i ultrastrukturne promene u tkivima neposredno po odmrzavanju.

Histopathologic and ultrastructural changes in the tissues of frozen extremities of Wistar rats were investigated immediately after thawing. Three experimental groups were formed: two were exposed to cryoinjuries of different intensity, while the third was the control one. Cryoinjury was caused by experimental model of local, controlled freezing of hind, right extremities. Immediately after thawing the tissue samples were taken from frozen right and unfrozen left extremities, in which histopathologic and ultrastructural changes were compared mutually and with control group, respectively. It was observed that the freezing directly caused ultrastructural and histopathologic damage of the tissues that were manifested immediately after thawing and were proportional to the intensity of freezing. Simultaneously, in the tissues existed complex circulatory disorders manifested in open arteriovenous shunts, venous congestion and microcirculatory insufficiency caused by evident spasm of arteriolae that could be considered to be very significant pathogenetic factor in ischemic damage of unfreezed tissues.

White Addison's disease: what is the possible cause?

A case of chronic primary adrenal insufficiency without hyperpigmentation in a 64-year-old woman is reported. Due to the absence of hyperpigmentation the diagnosis was delayed and she became critically ill. During endocrine evaluation, in order to investigate the mechanism responsible for the absence of hyperpigmentation, skin biopsy was done and hormones responsible for the skin pigmentation were measured. Absence of hyperpigmentation is explained by high degree of melanosome degradation in secondary lysosomes called "compound melanosomes", which overwhelmed increased stimulation of the skin pigmentation. Melanocyte-stimulating hormones were elevated with a strikingly high beta-LPH/ACTH ratio. To our knowledge, this is the first study of pathogenic mechanisms responsible for the absence of hyperpigmentation in white Addison's disease.

Assessment of osteogenic potential of the natural origin bioceramics implanted into the human infrabony periodontal defects.

The osteogenic potential of natural origin bioceramics implanted in human periodontal infrabony defects was investigated Histologic and electron-microscopic analyses of implants 3 and 4.5 months after implantation were used for the estimation of osteogenic potential. Results show that the bioceramics of natural origin with a microstructure and canalicular system of the natural bone has a strong osteogenic potential. Results of histologic and electron-microscopic analyses, performed four and half months after implantation, show that new bone has been formed in the places of absorbed or partially absorbed implant granules as also in the pores of implant granules. Histological structure of the newly-formed bone correspond to the structure of the matured lamellated bone.

Apoptosis induced by microtubule disrupting drugs in normal murine thymocytes in vitro.

Disruption of cytoplasmic and spindle microtubules by colchicine or nocodazole increases mitotic index, but it also enhances apoptosis in isolated mouse thymocytes; the apoptotic index exceeds 20% after 4 hours of incubation with either drug (5% in controls). Apoptosis was confirmed by DNA fragmentation, and was blocked by calcium chelators and inhibitors of protein synthesis. The apoptotic effect of microtubule disrupting drugs (MDD) was directed to interphase thymocytes and was independent on MDD action on mitotic cells. However, cell death of mitotically arrested cells showed ultrastructural changes similar in many aspects to apoptosis.

[The role and morphology of thrombocyte concentrates prepared from a buffy coat]. / Prinos i morfologija koncentrovanih trombocita pripremanih iz buffy coat-a.

The results of quantification and investigation of thrombocyte morphology in 112 concentrated thrombocyte units, prepared from buffy coat of the whole blood taken from the unchosen donors are shown. Immediately after the preparation of units the thrombocyte count was 66.99 +/- 7.04 x 10 cells (contribution of procedure 65.05%), the number of residual leukocytes 70.2 +/- 17.91 x 10 cells and the value of morphological thrombocyte score was 364 +/- 32.1. During the first day of storage on the temperature of 20 +/- 2 degrees C, along with the constant shaking of units the significant decrease of number of morphological score of thrombocyte (p < 0.05) was stated. Beside the mentioned side effects, the units of concentrated thrombocytes prepared in this procedure showed to be therapeutically effective after the storage of 5 days. In contribution to this spoke electronic-microscopic investigations that showed the presence of degenerative changes of thrombocytes during the fourth day of storage. Further improvement of procedure is necessary due to the prolonged preservation of the concentrated thrombocyte units quality.

Prevalence of G-to-T transversions among K-ras oncogene mutations in human colorectal tumors in Yugoslavia.

Human colorectal carcinoma tissue sampled from 37 patients, routinely graded into Dukes' stages A, B and C and histologically examined for the level of differentiation, were analyzed for the presence of point mutations in the K-ras oncogene. Seventeen cases out of the 37 analyzed were found to have a mutation in either the 12th or the 13th codon of the K-ras gene, giving an overall frequency of mutation of 46%. The incidence of mutations in Dukes' stages A, B and C was 33, 46 and 58% respectively. Although the frequency of mutation appears to be similar to that reported for the USA population, the spectrum of point mutations in codons 12 and 13 of the K-ras gene in the Yugoslav population appears to differ significantly. G-to-T transversions make up 77% of all mutations present, with the distribution as follows: 18% at the first base and 59% at the second base of codons 12 and 13. G-to-A transitions at the second base is the only other mutation identified, occurring mainly in codon 13 in colorectal tumors of all 3 stages.

[Ultrastructural changes in tumor cell nuclei during spontaneous regression of induced mouse sarcoma virus tumors]. / Ultrastrukturne izmene nukleusa tumorskih celija u toku spontane regresije MSV indukovanih tumora.

Experimental induction of tumours by mouse sarcoma virus inoculation into the Balb/c mice is a suitable model for following up the mechanisms involved in the regression processes, that is, degradation of tumour cells. Using the electron microscope the analysis of the nucleus of tumour cells in different phases of regression (from 8 to 23 day after inoculation) was performed in order to observe the mechanisms of degradation of tumour cells. It has been concluded that the changes of apoptosis of tumour cells occurred most frequently.

[Morphologic characteristics of HBV markers and products of iron metabolism in liver tissue in patients with hepatitis B virus]. / Neke morfoloske karakteristike markera HBV i produkata metabolizma gvozda u tkivu jetre bolesnika sa B virusnim hepatitisom.

In the histomorphologic analysis of 126 liver biopsies with hepatitis B virus (HBV) infection the authors have met some difficulties in the interpretation of findings of three biopsies which showed the presence of hemosiderine and ferritin deposits in hepatocytes. The lack of cells with the appearance of "ground glass", that is, ground glass hepatocytes which are one of the important features of HBV infection and aberration from the standard features in some histochemical stainings are noticed in all three biopsies. Since only few authors have noticed the same problem, it is possible that these results open new ways in the study of pathogenesis of HBV infection in the liver and its relationship with iron metabolism.