Biomedical subjects

I Selak

Publications and source records attributed to I Selak.

At least 19 recordsLinked to original sources

PubMed1998

Carcinoembryonic antigen (CEA) in colonic inflammatory-regenerative and dysplastic epithelial lesions.

AIM: Immunohistochemical study of carcinoembryonic antigen (CEA) distribution in inflammatory-regenerative and dysplastic changes of bowel mucosa. The relationship between the presentation of CEA and the intensity of inflammatory-regenerative and dysplastic processes in the flat colon mucosa was also examined. METHODS: Biopsy specimens from 105 patients were examined: 45 classified as inflammatory-regenerative and 60 as dysplastic (21 mild, 23 moderate, and 16 severe dysplasia). The expression of CEA was assessed on the basis of location, quantity, and intensity of CEA immunostaining, by counting antigen-positive cells, and the presence of antigen in the lumen of crypts and glycocalyx on the surface of the mucosa. Using a semiquantitative method, antigen staining intensity was defined as weak, moderate, and intense. RESULTS: The quantity of CEA in columnar, goblet mucous, and undifferentiated cells, as well as in the glycocalyx on the surface of the mucosa and in the crypts' content increased proportionally with the intensity of epithelial dysplasia. In inflammatory-regenerative lesions, CEA was located in the apical and supranuclear part of the cytoplasm, and in the dysplastic mucosa, in lateral and basal parts of the cells. CONCLUSION: The quantity of immunohistochemically demonstrable CEA and its intracellular distribution changed in the colon mucosa during the transition from regenerative to dysplastic epithelial lesions. The intensity of CEA expression was closely related to the intensity of dysplastic lesion.

Adult↗

PubMed1995

[Multiple neoplasms].

This paper describes observation on multiple carcinomas, with emphasis on double carcinomas of the lungs and other organs. The paper presents four cases of multiple neoplasmas and goes on to discuss eventual etiopathogenesis of multiple malignancies. Of the four cases presented in this paper, three cover double carcinoma of the throat and lungs, and in the fourth, double carcinoma of the lung and bladder. Three of the cases covered relate to metachronous carcinoma and the fourth case to synchronous carcinoma.

Humans↗

PubMed1994

[Diagnostic and prognostic contribution of somatosensory evoked potentials by truncular and dermatomal stimulation in lumbosacral radiculopathy. Apropos of 120 cases surgically-treated].

Lower-limb somatosensory evoked potentials (SEPs) of nerve-trunk (peroneal nerve, posterior tibial nerve) and dermatomal (L5 and S1) stimulation were recorded in 120 patients suffering from lumbosacral disk disease. Recordings were performed before surgery and on Days 4 and 50 after surgery. Electromyography was also performed before surgery. Dermatomal SEPs were shown to be sensitive (70%) and specific in both terms of their lateralizing value and their ability to identify the L5 or S1 level. Moreover, combining SEPs and EMG significantly increased the sensitivity of the electrophysiological testing when compared with each method alone. There was no relationship between SEPs performed before surgery and surgical outcome. Inversely, we demonstrated the prognostic value of SEPs performed on Day 4, SEP normalization at Day 4 was associated with a good outcome at Day 50 in 91.8% of examined cases, while the persistence of pathological SEPs at Day 4 was associated with poor outcome at Day 50 in 56% of the cases.

Adult↗

PubMed1993

[Acute hemorrhagic ulcer in a 3-month-old child].

A case of the acute haemorrhaging ulcus in a three-months old infant with lethal outcome is presented in this paper. The unclear proximal gastrointestinal haemorrhage didn't indicate the possibility of the presence of ulcer, due to the absence of frequent etiologic factors of the inception at this age.

Acute Disease↗

PubMed1993

[Morphologic changes in the pulp and surrounding structures of the teeth in irradiated animals].

Several animals of the same breed (11 swine-white Landrace) were used in the research. Irradiation was made by radiation from the linear accelerator with lethal doses (3,68-4, 48 Gy). The changes on incisors and molars in the perished animals were observed as well as the changes on the surrounding structures of teeth. In the examined histological incisions of the dental pulp, paradontium, alveolar part of the bone and gingival part of the mucose of the oral cavity in the animals were found extensive confluent bleeding, dilatation of blood vessels with expressive edema of blood vessels intima. The endothelium showed the signs of edema, prominence toward the lumen or desquamation in the lumen. There were shallow defects in the gingival mucosa due to the necrosis and desquamation top-cover epithelium. The described changes fit into the findings of a large number of researches who accent hemorrhagic diathesis with petechial ecchymotic and confluent bleedings in many organs and tissues.

Animals↗

PubMed1992

[Dental pulp in carious teeth].

Various etiologic causes lead to dental pulp changes ranging from inflammation to necrosis. The most frequent changes, however, are caused by bacterial activity and toxins from carious process. According to the opinion of various authors and on the basis of our investigations the conclusion can be made that all the forms of dental pulp changes can be developed as the sequela of the disease of supporting apparatus. Pathohistologic examination of dental pulp of cariously damaged teeth showed that the occurred changes are mostly the sequela of inflammation and regressive and progressive changes are found as well.

Adult↗

PubMed1990

[Isolation of viruses from autopsy material during the Coxsackie virus epidemic in Sarajevo in 1985].

In this paper were presented results of isolation of vira from some organs of the dead newborn infants during the epidemy Coxsackie B virosis in Sarajevo in 1985. 12 newborn died. Obduction was done in seven newborn. From the seven obducated, in six were isolated Coxsackie B-3 vira from heart, lungs, brain, liquor, blood, heart blood but the attempts of isolation of the vira from intestine and from pericardial liquor did not succeed.

Coxsackievirus Infections↗

PubMed1990

[Neurological involvement as manifestation of Behçet's disease. 4 clinical case reports].

We report four patients with Behçet's disease characterized by initial and predominant neurological signs and symptoms. In three cases, a clinical picture of relapsing meningoencephalitis preceded the appearance of the classical signs of the disease for several months or years; in the fourth case, an acute febrile aseptic meningitis coincided with the development of bipolar aphthosis and uveitis. Disease activity was linked to a blood inflammatory syndrome and neutrophilic leucocytosis. Acute phases were associated with CSF mixed pleocytosis and high protein content. Brain CT scans and MRI were very effective to detect lesions which are mainly located in the brain stem and basal ganglia. High-dose corticosteroids and, in cases of relapses, immunosuppressive drugs were required to treat these severe forms of Behçet's disease.

Adult↗

PubMed1987

Potassium-induced release of neuronotoxic activity by astrocytes.

Medium conditioned by newborn rat cerebral cortex microexplants contains neuronotoxic activity for cerebellar granule cells and hippocampal neurons. The neuronotoxic activity is associated with low-molecular weight molecule(s) (less than 1000 Da) and resists to heating and to freezing and thawing. Using nearly homogenous cultures of neurons or astrocytes, we show that the neuronotoxic activity is released by the latter cell type. This release is enhanced by increasing extracellular K+-concentration. Astrocytes also secrete neuronotrophic activity whose release is not affected by external K+. Neurons can be desensitized against the neuronotoxic activity.

Animals↗

PubMed1987

Plasminogen activators in developing peripheral nervous system, cellular origin and mitogenic effect.

Newborn rat dorsal root ganglia release two different plasminogen activators (PAs): the urokinase (UK) and the tissue (tPA) type. The former is secreted by neurons while the latter is secreted by Schwann cells. tPA release by Schwann cells is modulated by choleratoxin, a known mitogen for these cells. UK but not tPA stimulates in a dose-dependent fashion the proliferation of Schwann cells. This effect is observed in the absence of plasminogen, suggesting that the substrate for PAs in the developing nervous system is not plasminogen. Since UK is secreted by neurons, our data suggest a new mechanism for neuronal control of Schwann cell proliferation.

Animals↗

PubMed1985

Central nervous system-directed neuronotrophic activity present in red blood cells.

A new neuronotrophic factor has been identified in extracts of vertebrate red blood cells. The factor supports the survival in culture of neurons from vertebrate central nervous systems, and does not support the survival of several peripheral ganglionic neurons. The active molecule appears to be a slightly acidic protein of 30,000-100,000 daltons.

Animals↗

PubMed1985

Plasminogen activator is a mitogen for astrocytes in developing cerebellum.

Newborn rat cerebellum microexplants cultured in Minimal Essential Medium with glucose and insulin released plasminogen activator (PA), which was detected in living cultures by a substrate overlay assay. Gel electrophoresis of cerebellum-conditioned medium followed by zymography resolved PA activity in two separate bands of 48,000 and 75,000 daltons apparent mol. wt. Using specific antisera, these bands were shown to be respectively urokinase and tissue-type PA. Cerebellum conditioned medium as well as purified human urokinase induced the proliferation and outgrowth of glial fibrillary acid protein-positive cells from newborn cerebellar microexplants. The effect was suppressed by the serine protease inhibitor phenyl methanesulfonylfluoride. Since PAs are most likely of neuronal origin, we suggest that at least one of these proteases acts as a neuronoglial mitogenic signal during development.

Animals↗

PubMed1985

Laminin promotes cerebellar granule cells migration in vitro and is synthesized by cultured astrocytes.

Newborn rat cerebellum microexplants have been used as a model to study neuronal migration. Laminin in a substrate-bound form modifies extensively the migratory behavior of the neurones, an effect which is blocked if antilaminin antibodies are present during the assay. 35S methionine incorporation followed by SDS-PAGE electrophoresis, fluorography and immunoprecipitation with antilaminin antibodies allowed to demonstrate that laminin is synthesized and secreted by cultured newborn rat cerebellum as well as by cultured newborn rat cerebral cortex astrocytes.

Animals↗

PubMed1985

Pyruvate participation in the low molecular weight trophic activity for central nervous system neurons in glia-conditioned media.

Conditioned media from glial cell cultures contain low molecular weight agents which can support survival of CNS neurons in the absence of recognized protein neuronotrophic factors. A similar support is provided to CNS neurons by selected basal media, and pyruvate is the critical medium constituent responsible for their trophic competence. Eagle's basal medium, which contains no pyruvate, acquires pyruvate when conditioned over astroglial cell cultures. Enzymatic degradation of the pyruvate in the astroglia-conditioned medium leads to corresponding losses in its low molecular weight trophic activity for CNS neurons. Quantitative correlations between pyruvate content and CNS trophic activity demonstrate that pyruvate is the main trophic ingredient of the glia-conditioned medium, and other low molecular weight substances, acquired during conditioning, reduce the pyruvate concentration required for its trophic effect. The "pyruvate-sparing" substances, as yet unidentified, are not the serine and Fe3+ which have pyruvate-sparing competence for peripheral, ciliary ganglionic neurons. These findings, together with previous observations, propose that prenatal neurons fail to generate or retain endogenous pyruvate at the levels for their survival-sustaining activities.

Animals↗

PubMed1984

Chemically defined requirements for the survival of cultured 8-day chick embryo ciliary ganglion neurons.

We have previously demonstrated that both peripheral and central neurons from embryonic chick and newborn mouse can be maintained in a serum-free defined culture medium containing the appropriate neuronotrophic agent and the N1 supplement consisting of insulin, transferrin, putrescine, progesterone and selenite. In the present studies we have examined the short-term survival requirements of 8-day embryonic chick ciliary ganglion (CG) neurons. By comparing CG neuronal survival in our standard culture medium, Eagle's Basal Medium (EBM), with several other commercially available basal media, we have established that CG neurons also have specific requirements for pyruvate, serine and iron (Fe3+), in addition to their trophic factor (Ciliary Neuronotrophic Factor, CNTF) and the N1 supplement. The data suggest the existence of 3 subsets of CG neurons differing in their essential needs, namely: (1) those supported by glucose in the absence of pyruvate, (2) those requiring exogenous pyruvate but not serine or Fe3+, and (3) those which need pyruvate, serine and Fe3+. The minimal effective concentration of pyruvate could be decreased by a factor of 50 in the concurrent presence of serine and Fe3+. Serine was also a limiting element in the survival of some of these CG neurons. The Fe3+ concentration required by the same neurons was considerably diminished with the availability of transferrin, perhaps reflecting an increased Fe3+ transmembrane transport efficiency. Insulin was found to be the only N1 ingredient required for the survival of CG neurons. Insulin was a constant requirement for all 3 subsets of CG neurons, even when cultured in the total absence of glucose (but presence of pyruvate).

Animals↗

PubMed1984

Neuronotrophic activities in cerebrospinal fluid of head trauma patients.

Neuronotrophic factors (NTFs) are agents required for neurons to survive in tissue culture. In this study, we investigated the presence of NTFs in cerebrospinal fluid (CSF) of patients with central nervous system (CNS) injury. Cerebrospinal fluid was collected from 15 patients with acute CNS lesions in whom ventricular catheters had been placed to monitor and to facilitate the control of intracranial pressure. Neuronotrophic activity within the CSF was assayed using cultures of neurons derived from fetal rat hippocampus and embryonic chick cerebral cortex. Cerebrospinal fluid from all 15 patients contained NTFs which supported the survival of rat hippocampal neurons. Survival of chick cortex neurons was supported by eight of nine CSF samples. In the 11 patients from whom consecutive CSF samples were available, NTF activity assayed in rat hippocampal cultures tended to decrease during the first several days after CNS injury. In CSF collected from three patients by lumbar puncture for diagnosis of "nontraumatic" conditions, no NTFs were detectable. NTFs supporting hippocampal neurons were also detected in extracts of blood clot obtained from normal volunteers. Neuronotrophic activity in the CSF was heat sensitive, nondialyzable, and macromolecular, suggesting its association with a protein(s). These observations suggested that (i) NTFs are detectable in human CSF after CNS injury, (ii) NTFs appear in response to the injury itself, and (iii) at least some human NTFs can support the survival in culture of nonhuman CNS neurons.

Animals↗

PubMed1984

Cerebellar macroneurons in serum-free cultures: evidence for intrinsic neuronotrophic and neuronotoxic activities.

Cerebellar macroneurones survive and differentiate for at least 10 days in Eagle's minimum essential medium with insulin as the only supplement when cultured either as microexplants or in high-density dissociated cultures, while they do not survive if cultured in low density. The survival is related to the extracellular release of neuronotrophic factor(s). Using a quantitative bioassay of the neuronotrophic effect, it is possible to demonstrate that the effect is concentration dependent. The analysis of the dose-response curves suggests that the neuronotrophic activity is associated with a neuronotoxic activity. The two activities can be segregated using a simple physical method, allowing direct demonstration of the neuronotoxic activity.

Animals↗

PubMed1984

Use of central neuronal cultures for the detection of neuronotrophic agents.

Neuronotrophic factors, a class of macromolecules thought to be present within the neuronal environment are required to support the survival in vitro of peripheral neurons. In the present study we have established bioassay culture systems suitable for the identification of similar agents for intrinsic neurons of the central nervous system. The striatum, hippocampus and septum of 18 day fetal rats were dissociated and plated in a serum-free medium on a neurite conducive substratum which allows an easy recognition of neurons under phase contrast microscopy. These cultures contain predominantly neurons as assessed by tetanus toxin labelling, a well recognized neuronal marker. Seeding the cell suspensions at decreasing densities yields after 24 h a density dependent survival of the neuronal population. Thus a low seeding density could be chosen where survival of these neurons required an exogenous source of trophic factors. Survival of central neurons was promoted by several conditioned media derived from rodent glial cell cultures, both primary (astroglia, Schwann) and clonal (C6 glioma, Schwannoma). Serial dilutions of these media allowed the titration of their respective neuronotrophic activities. In addition, conditioned media derived from the central neuronal cultures themselves, when seeded at a high density, were also able to support the survival of low density seeded central neurons.

Animals↗