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K Zarković

Publications and source records attributed to K Zarković.

16 recordsLinked to original sources
PubMed2004

Advanced glycation endproducts in peripheral nerve in type 2 diabetes with neuropathy.

Advanced glycation endproducts (AGE) accumulate over proteins as a consequence of diabetic hyperglycemia, and thus contribute to the pathogenesis of diabetic complications. To improve the understanding of the pathology of diabetic neuropathy, AGE accumulation was analyzed in sural and/or femoral nerves obtained under spinal anesthesia from 8 type 2 diabetic patients with both distal symmetrical polyneuropathy and proximal neuropathy. Pronounced AGE immunoreactivity was detected on axons and myelin sheaths in 90% of diabetic peripheral nerves but not in the control specimen. The intensity of axonal AGE immunopositivity significantly correlated with the severity of morphological alterations (p<0.005). AGE localization, demonstrated by immunohistochemical methods, was also present in the endoneurium, perineurium and microvessels. Morphometric analysis of the diabetic peripheral nerve showed perineurial thickening (diabetic vs. control, 15.5+/-4.9 vs. 6.6+/-2.1 microm, p<0.001), narrowing of the microvessel lumina (66.6+/-50.5 vs. 579.5+/-38.4 x10(3) microm(2), p<0.001) and significant reduction in the number of preserved axons (3.6+/-3 vs. 8.9+/-2.3 per 10(5) microm(2) per area, p<0.037). The sera of diabetic patients contained epitope(s) of AGE structure and soluble immune complexes containing AGE moiety. In conclusion, to the best of our knowledge, this is the first study providing evidence for excessive AGE formation on peripheral nerve components, primarily axons, and a significantly higher level of circulating AGE-immune complexes in patients with both distal diabetic polyneuropathy and proximal neuropathy. Humoral immune mechanisms, including the production of anti-AGE autoantibody, may potentially be involved in the development of structural abnormalities described in this report.

Aged↗
PubMed2003

Extranodal sinus histiocytosis (Rosai-Dorfman disease) of the brain parenchyma.

Rosai-Dorfman Disease (RDD) is an idiopathic histiocytic proliferation affecting lymph nodes. Although extranodal involvement has been reported in diverse sites, manifestation in the central nervous system (CNS) is extremely rare, particularly in the brain parenchyma. A 39-year-old male presented with an isolated well-circumscribed brain mass in the right temporal lobe, preoperatively thought to be a meningioma. Histology and immunohistochemistry confirmed that the lesion was RDD. The intraparenchymal brain location of RDD appears to have a benign course. Although the adjuvant therapy is a treatment of choice, surgical resection seems to be the appropriate treatment modality. From the clinical point of view RDD might be an important intracerebral entity because it may mimic other lesions, particularly other histiocytic disorders.

Adult↗
PubMed2000

Growth promoting effect of human plasma ultrafiltrate bioactive fraction (TBP) for human non-functioning pituitary adenoma cells in vitro.

We described before that the chromatographically purified "human plasma ultrafiltrate bioactive fraction" (humoral factor tentatively denoted as tumor basic protein--TBP) regulates in vitro release of ACTH from pituitary adenomas stimulating the hormone release from the tumors showing low hormonal activity in vitro and inhibiting ACTH production in vitro by highly hormonally active pituitary tumors. In this study we describe growth promoting effects (determined by 3H-TdR incorporation assay) of TBP (5 microg/l, i.e. 10% w/v plasma equivalent concentration) for 10 non-functioning pituitary tumors. The effects of TBP appeared to negatively correlate with the in vitro growth abilities of the tumors that were otherwise dependent on the duration of the clinical symptoms of the tumor presence. Hence, similar to its effects on hormonal activity of the pituitary tumors, TBP stimulated the growth of the tumors which did not express high spontaneous 3H-TdR intensity, but did not stimulate the cells with high capacity of spontaneous 3H-TdR incorporation. Moreover, all the tumors that were stimulated by TBP were nononcocytic adenomas while oncocytoma cells were not stimulated at all. Thus, TBP shows activity of humoral (plasma) factor involved in the growth regulation of pituitary adenomas that might be used to define the growth abilities of these tumors, especially in case of null cell adenomas and oncocytomas as were the tumors used in this study.

Adenoma↗
PubMed2000

Involvement of lipid peroxidation, oncogene expression and induction of apoptosis in the antitumorous activity of ferric-sorbitol-citrate.

We described before that iron-containing, anti-anaemic drug, ferric-sorbitol-citrate complex (FSC) inhibited proliferation of various murine cancer cells in vitro and caused tumour regression in vivo, but did not affect proliferation of the non-malignant cells. The aim of this study was to evaluate further the anticancer activity mechanism of FSC using human colon cancer cell line CaCo2. After treatment with FSC for 72 hours impaired proliferative ability and viability of CaCo2 cells as observed. Growth modification caused by FSC involved diminished expression of Bcl-2, and over-expression of mp53 proto-oncogenes, accompanied by increased incidence of apoptosis. Immunostaining the cells applying monoclonal antibodies for lipid peroxidation product 4-hydroxynonenal (HNE) showed that FSC-iron increased intracellular HNE, but did not induce severe HNE-mediated oxidative stress. Thus, antitumorous mechanism of FSC involves modulation of oncogene expression and induction of apoptosis apparently not triggered by lipid peroxidation-mediated oxidative stress, although FSC might restore endogenous HNE production in the CaCo2 cells to level resembling physiological for various non-malignant cells and tissues. Higher dose of FSC increased also number of intracellular ferritin positive CaCo2 cells.

Aldehydes↗
PubMed2000

Evolution of clinical symptoms in a young woman with a recurrent gonadotroph adenoma causing ovarian hyperstimulation.

OBJECTIVE: To demonstrate the clinical course in a young female with gonadotroph adenoma causing ovarian stimulation. PATIENT AND METHODS: Our patient was a 23-year-old woman with a history of oligomenorrhea who had previously undergone bilateral ovarian wedge resection owing to the clinical appearance of polycystic ovaries. Two years later, she sought treatment for headache, galactorrhea, history of spotting and lower abdominal distension. FSH, LH, beta-LH, inhibin A and B, estradiol, prolactin (PRL), and beta-chorionic gonadotrophin (beta-CG) were measured, and the responses of FSH, LH and beta-LH to thyrotrophin-releasing hormone (TRH) were documented. Immunohistochemical analysis of the tumor tissue was performed after surgery. Five years after the trans-sphenoidal surgery, the patient again became oligomenorrheic. A large recurrent adenoma was diagnosed on CT one year later. Transvaginal ultrasound showed ovaries of normal size with multiple small cystic formations simulating a polycystic pattern, While the patient was awaiting surgery, a pituitary apoplexy occurred. Emergency decompressive surgery was performed and the patient fully recovered. RESULTS: Enlarged ovaries were found on ultrasound examination simulating a hyperstimulation-like pattern. At that time, elevated levels of FSH (13.4IU/l) and marginally elevated levels of beta-LH (1.43ng/ml) were found, whereas the level of LH (0.5IU/l) was subnormal. Plasma estradiol was markedly supranormal (6150pmol/l). Levels of inhibin A and B were elevated (326pg/ml and 588pg/ml respectively). The prolactin level (70ng/ml) was increased, whereas beta-chorionic gonadotrophin (beta-CG) was normal. Significantly increased FSH, LH, and beta-LH responses to TRH stimulation were documented. Pituitary macroadenoma was found on MRI scan and removed by trans-sphenoidal surgery. Immunohistochemical examination showed high positivity for beta-CG and LH, and slight positivity for FSH. Five years after the surgery, estradiol was elevated (1160pmol/l), whereas basal levels of LH (4.65IU/l) and FSH (3.98IU/l) were not suppressed. After the second operation, immunostaining of the adenoma tissue confirmed the previous findings. CONCLUSIONS: Measurement of gonadotrophins in our case did not prove to be a method for identifying a large recurrent gonadotroph pituitary adenoma. The sonographic ovarian imaging varied from a polycystic- to an ovarian hyperstimulation-like pattern during the evolution of the tumour.

Adenoma↗
PubMed1999

4-Hydroxynonenal as a second messenger of free radicals and growth modifying factor.

Immunohistochemical analysis of the distribution of the lipid peroxidation product 4-hydroxynonenal (HNE) in the brain of baboons exposed to experimental hemorrhagic traumatic shock or sepsis showed that systemic oxidative stress and the thereby generated HNE affect the blood:brain barrier and the regulation of cerebral blood flow determining secondary brain damage. Similarly, HNE was determined during ischemia in the brain blood vessels of rats exposed to ischemia/reperfusion injury of the brain. After reperfusion, HNE disappeared from the blood vessels but remained in neurones and in glial cells. Since HNE modulates cell proliferation and differentiation (including proto-oncogene expression), it is postulated that HNE might have prominent local and systemic effects that are not only harmful but beneficial, too, determining the outcome of various pathophysiological conditions based on oxidative stress.

Aldehydes↗
PubMed1999

Clinical and morphological features of undifferentiated monomorphous GH/TSH-secreting pituitary adenoma.

A 41-year-old male presented with progressive visual defects, acromegaly and hyperthyroidism. After clinical evaluation a giant GH/TSH-secreting pituitary adenoma was diagnosed. Administration of the somatostatin analog octreotide at doses of 150 microg s.c. per day inhibited the secretion of both GH and TSH. A three-week treatment with octreotide prior to surgery led to slight visual improvement and CT scan showed some new necrotic areas within the tumor mass. Transcranial surgery was performed. By immunohistochemical analyses of the adenoma tissue GH, prolactin and beta-chorionic gonadotropin were detected; TSH was negative. Electron microscopy revealed an undifferentiated, monomorphous adenoma with morphological features of an acidophil stem cell adenoma such as the presence of misplaced exocytoses, fibrous bodies and mitochondrial gigantism. However, the tumor cells contained small secretory granules (up to 250 nm) accumulated along the cell membrane characteristic of thyrotrope cells. Furthermore, some adenoma cells were fusiform with long cytoplasmic processes resembling thyrotropes. Two months after the operation CT scan revealed a large residual tumor. Serum GH and TSH levels had increased again and the TSH level was even higher than before the treatment. The patient died suddenly, most probably of lethal arrhythmia. Specimens of the adenoma tissue obtained at autopsy confirmed the previous findings with the exception of positive immunostaining for TSH which was found in less than 1% of the adenoma cells. This undifferentiated, monomorphous GH/TSH-secreting pituitary adenoma represents an entity that is unusual both in its ultrastructural features and clinical manifestations suggesting a cytogenesis from an early, undifferentiated stem cell.

Adenoma↗
PubMed1996

Analysis of the in vitro secretory activity of human pituitary adenomas: modification of corticotropin release from adenoma tissue explant cultures by addition of a human plasma ultrafiltrate bioactive fraction.

The lack of control of tumour behaviour is manifested in different ways, depending primarily on the type of tumour. This results in numerous problems of tumour diagnosis and therapy. In the case of "benign" tumours, like pituitary adenomas, in vitro studies are often used for evaluation of the tumour. The use of tissue explant cultures of human pituitary adenomas and the comparison of the feature of cultured tumours with their behaviour in vivo showed that corticotropin is released not only from the tumours associated with Cushing's disease, but also from clinically non-functioning tumours. Hence, it was supposed that the release of corticotropin in vivo from non-secreting tumours is probably under the influence of certain neuroendocrine and/or systemic humoral factors. To test this possibility, samples of 22 tumours were cultured in plain culture medium or in the presence of the "human plasma ultrafiltrate bioactive fraction" (tentatively termed as TBP) prepared by anion-exchange chromatography. In the presence of TBP the release of corticotropin was strongly inhibited in adenomas showing relatively high spontaneous secreting activity in vitro (> 200 ng/l in 24 hours), while immunohistochemistry of these tumours indicated accumulation of corticotropin inside the cells. In contrast, TBP stimulated corticotropin release from tumours that showed relatively low basic corticotropin release (< 200 ng/l in 24 hours), with no obvious change in cellular corticotropin immunoreactivity. Such a dual activity of TBP was not observed for 8 samples of adenomas cultured in the presence of surrounding pituitary tissue, probably because TBP did not affect corticotropin secretion by the normal pituitary cells (as indicated by immunohistochemistry). From these results, it appears that TBP could be one of the humoral factors involved in the regulation of corticotropin release from pituitary adenoma tissue. Its possible involvement in the regulation of corticotropin release from normal pituitary tissue, however, is uncertain.

Adenoma↗
PubMed1995

Comparison of the values of basic fibroblast growth factor determined by an immunoassay in the sera of patients with traumatic brain injury and enhanced osteogenesis and the effects of the same sera on the fibroblast growth in vitro.

In patients with severe traumatic brain injury, the early healing of fractures is accompanied by hypertrophic callus formation or heterotopic ossifications, which might even result in ankylosis of the affected joints. Analysis of the sera of patients with traumatic brain injury revealed post-traumatic dynamic changes of basic fibroblast growth factor immunoreactivity, similar to those observed during fracture healing associated with enhanced osteogenesis. The aim of this study was to determine whether such changes in basic fibroblast growth factor concentrations could be related to the phenomenon of enhanced osteogenesis. Basic fibroblast growth factor immunoreactivity was determined (using an IEMA kit) in the sera of patients with traumatic brain injury and bone fractures (n = 8) and in the sera of patients with either traumatic brain injury alone (n = 10) or bone fractures alone (n = 7), and the effects of these sera on L929 fibroblast growth were analysed in vitro. The results did not prove a causative relationship between the changes of basic fibroblast growth factor immunoreactivity and in vitro growth promoting effects of the sera. However, it is apparent that, in addition to changes in the growth-promoting activity and basic fibroblast growth factor concentration of serum, other as yet unknown post-traumatic changes can cause enhanced osteogenesis.

Adolescent↗
PubMed1991

CT detection of minimal brain lesions in closed cerebral trauma.

From the group of patients with clinically manifested closed head injuries, patients with minimal traumatic lesions in the brain parenchyma, were separated and in addition radiographically analyzed. There were 22 patients in the group. On plain CT scans they had foci 5 to 10 mm large caused by trauma. CT is suitable investigation technique for detecting minimal traumatic brain lesions. Besides, CT is suitable for the follow up of the lesion evolution dynamics, which comprises not only changes in the lesions density but also the possibility of registering primarily reversible but macroscopically (invisible) lesions into (visible) reversible lesions on the control scans. The finding of only one or two minimal lesions in critical locations in the "inner cerebral trauma" always indicated the existence of possible lesions in other locations within the known pattern of the ICT. Minimal traumatic lesions of the brain frequently occur in ICT or in all cases where the acceleration of traumatizing forces has anteroposterior or postero-anterior course of direction. Their recognition by neuroimaging methods is of great importance due to the central localization of the foci, which otherwise cannot be detected by other methods.

Adolescent↗
PubMed1991

Distribution of traumatic lesions of corpus callosum in "inner cerebral trauma".

This study deals with the topographic distribution of traumatic lesions in the corpus callosum within the pattern of "inner cerebral trauma". Material for neuropathological investigations consisted of 49 brains of patients who suffered closed head injury of the acceleration type with linear translation of acceleration acting along the longer axis of the head. As a control, 5 brains were investigated in which the direction of linear translation was latero-lateral. The patients were divided into 4 groups according to reconstruction of the traumatic event and ascertaining of the direction of the linear translation of acceleration: (1) Medial blow (antero-posterior and postero-anterior), (2) Semioblique left blow (frontal left-occipital right and occipital right-frontal left), (3) Semioblique right blow (frontal right-occipital left and occipital left-frontal right), (4) Vertex-base direction. Fornix and septum pellucidum, as anatomically adjacent structures were also investigated. The results showed that the lesions in the corpus callosum were related to the pattern of "inner cerebral trauma" (ICT) (Grcević 1982), and the biomechanical conditions originally proposed by Lindenberg. These investigations, carried out on a representative material of 54 brains and by subserial histological analysis of the entire corpus callosum, produced a new evidence for our previous preliminary observations about the correlation of the shape and distribution of the periaxial lesions of the pattern of "inner cerebral trauma" and direction of the linear translation of accelerating forces. Our present investigations showed a striking congruence between the pattern of lesions within the corpus callosum in such type of cerebral trauma and the course of linear translation of acceleration. Furthermore, this study proved the importance of topographic interpretation of lesions in the corpus callosum in vivo i.e. by the CT and MRI examinations, because they may serve as a significant information for reconstruction of the biomechanical conditions of the injury which can be of importance for early therapeutical strategy and forensic interpretations of the accident. By using silver impregnation-techniques for histopathological study of the corpus callosum, we could confirm our previously expressed concept on "focalized" and not "diffuse" axonal injures in ICT (Grcević 1988). In this study corpus callosum served as a representative anatomical structure for axonal studies showing that axonal lesions strictly follow the pattern of tissue lesions with definite focal principle.

Acceleration↗
PubMed1991

The occurrence of Rosenthal fibres in the brain tissue around meningioma.

A case of endotheliomatous type of meningioma arising from the falx and dura of the left anterior cranial fossa is reported. Numerous Rosenthal fibres were observed in the gliotic tissue around the meningioma. Authors present a brief data about the nature and occurrence of Rosenthal fibres. The occurrence of the pilocytic astrocytes and Rosenthal fibres in the gliotic tissue around slow-growing falx meningioma is an additional evidence for a peculiar type of changes in astrocytes of the long-standing gliosis of piloid type.

Brain↗
PubMed1990

Medullomyoblastoma.

A case of medullomyoblastoma, arising in the cerebellar vermis of a five-year-old boy, is presented. The light and electron microscopic features of the tumor are described and compared to other published cases. Within typical medulloblastoma areas light microscopy revealed signs of neuroblastic differentiation thus indicating its neuroepithelial origin. No signs of glial differentiation were found. Myogenic tumor component formed irregular, distinctly separated islands although some intermingling of two cell types was observed at the borders between the two zones. Within the myogenic tumor component, electron microscopy revealed rhabdomyoblastic elements in different stages of differentiation, frequently forming small groups encompassed by the same basement membrane. No indication of a common host cell for two cell lines was observed. No mesenchymal elements other than muscle, and no indication of possible teratoid origin of this tumor were observed. Considering histogenesis of muscle elements within this neuroepithelial tumor, the origin from multipotential neural-crest-derived ectomesenchymal cells seems the most appropriate one.

Cerebellar Neoplasms↗
PubMedDate not supplied

[Importance of the CRH (corticotropin releasing hormone) test in the differential diagnosis of Cushing's syndrome].

In the group of 13 patients with Cushing's syndrome (CS) CRH test was performed by sampling the blood from peripheral vein and in eight patients also after inferior petrosal sinus catheterization (IPSC) to resolve the disease etiology. In the group of patients with Cushing's disease (CD, n = 11), which was proven by surgery and adenoma immunohistochemistry, 10/11 had in CRH test the significant increase of cortisol and ACTH in the peripheral blood. Among two patients with ectopic ACTH syndrome one had the significant increase of both hormones in CRH test. After IPSC the ratio of ACTH in the petrosal sinus and in the peripheral vein was significant in 4/8 patients before, and in 6/8 after CRH administration. The intersinus gradient was significant in 3/8 patients before, and in 4/8 after CRH test. According to our results we can conclude that the determination of ACTH in the blood from peripheral veins after CRH administration is a very sensitive method for differential diagnosis of CS, while the results after IPSC were less sensitive in our conditions than those described in the literature.

ACTH Syndrome, Ectopic↗
PubMedDate not supplied

[Inhibition of growth of B16 melanoma caused by liver regeneration].

Phenomenon of spontaneous regression of cancer indicates that recovery from malignant disease can happen without the application of any so far known therapeutic treatment. The most of the self-cured patients have undergone surgical operation which did not eliminate entire tumor or did not affect malignant tissue at all. Furthermore, regression or reversion of tumors (transformation of tumor cells into normal, nonmalignant cells) can be achieved in plants or amphibia after exposure of tumor cells to the influence of normal, regenerating tissue. Thus, it seems that during tissue regeneration certain local changes in tissue happen (synthesis of some regulatory growth factors) which induce dying of tumor cells or modify main features of malignant cells. Previously we have studied growth of murine malignant tumors in regenerating tissue of liver and skin. Obtained results indicated that under the influence of regenerating tissue anaplasia of fibrosarcoma decreases, as well as do pigmentation and the incidence of live cells in melanoma B16 tissue. Thus, it is obvious that mechanism of regenerating tissue growth control, which can also change characteristics of tumor cells, exists in mammalia, too. In order to analyse whether the same homeostatic mechanism is responsible for the phenomenon of spontaneous regression of human cancer, we have analysed the growth of melanoma B16 in back limb of nonoperated and sham or partially hepatectomized mice. Regeneration of skin and abdominal wall tissue in sham hepatectomized animals slowed down tumor growth, while liver regeneration completely inhibited tumor progression. Tumor growth inhibition was result of tumor tissue necrosis which developed around blood vessels. However, the structure and integrity of blood vessels themselves was normal.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗