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Biomedical subjects

A Romaniuk

Publications and source records attributed to A Romaniuk.

At least 37 records · Page 2Linked to original sources
PubMed1989

Interleukin 2 receptor in rat heart allograft rejection.

Soluble interleukin 2 receptors (S-R-IL-2) of truncated Tac chain, produced in vitro during T lymphocyte activation, may represent an in vivo marker of an alloimmune reaction. We analyzed serum S-R-IL-2 production during acute heart allograft rejection and compared soluble and membranous Tac chain (blood lymphocytes and graft invading cells) regulation during rejection. Serum S-R-IL-2 was tested in an immunoradiometric assay, with a combination of two mouse IgG1 anti-IL2-R mAbs (ART18 and OX39). Membranous Tac chain was analyzed by immunochemistry in graft tissue, and by immunofluorescence on blood and spleen leukocytes. Four experimental groups were used: untreated allogeneic, untreated syngeneic, CsA-treated (10 mg/kg/day for 15 days) allogeneic and CsA-treated syngeneic graft recipients. In the untreated allogeneic group, S-R-IL-2, tested every day until rejection (9.14 +/- 1.6 days), increased as early as day 3 after transplantation, peaked at day 6, and plateaued thereafter. The allograft was infiltrated at day 5 by Tac chain-positive cells (10% of OX1 cells and 84% of OX19 cells). A small percentage of mononucleated cells was labeled in blood, but not in spleen, by ART18 and OX39 at day 7 only. In contrast, in untreated syngeneic and CsA-treated allogeneic combinations, there was no increase of baseline S-R-IL-2 level (P less than 0.001), and graft infiltrate did not contain IL-2-R positive cells. CsA treatment prolonged heart allograft survival (41.3 +/- 2.8 days). Baseline S-R-IL-2 levels during treatment were lower than those observed in untreated animals. In the CsA-treated allogeneic group, after CsA treatment interruption, S-R-IL-2 levels significantly increased, reaching a plateau at day 37. Results suggest that S-R-IL-2 measurement can be useful for clinical diagnosis of allograft rejection.

Animals↗
PubMed1989

Is it advisable to use sorbitans in the investigation of the brain mechanisms?

Injection of 0.1% saline solution of Tween 80 i.p. (3 X 3 cm3/kg/12 h) in the cat decreased the carbachol-induced growling response 36 h after the last injection. The content of 5-hydroxyindoleacetic acid (5-HIAA) increased in the hypothalamus, midbrain and amygdala, which indicates the increase in serotonin (5-HT) turnover and the 5-HT system activity. The results indicate that Tween 80 causes per se both behavioral and neurochemical changes. Therefore, it is inadvisable to add sorbitans to the solutions used in the investigation of the brain mechanisms.

Animals↗
PubMed1989

Serotonin depletion with P-chlorophenylalanine in the cat: effects on carbachol-induced defensive behavior and regional brain amine content.

Serotonin (5-HT) depletion with p-chlorophenylalanine (p-CPA) (3 X 150 mg/kg/12 h i.p.) in the cat resulted in an increase in the carbachol-induced growing response 36 h after the last injection. Besides important depletion of 5-HT in the anterior and posterior hypothalamus, midbrain and amygdala, and 5-hydroxyindoleacetic acid (5-HIAA) in the anterior and posterior hypothalamus and midbrain, dopamine (DA) level significantly increased in the amygdala and posterior hypothalamus with tendency to increase in the anterior hypothalamus and midbrain. No changes in noradrenaline (NA) level were observed. The results indicate that the carbachol-induced defensive behavior significantly increased as a consequence of reduction in the 5-HT system activity. The changes in DA content indicate that there are interactions between the 5-HT/DA systems.

Animals↗
PubMed1989

Prolongation of heart allograft survival in course of donor specific antigen and alloserum treatment in the rat.

Different cell subpopulations involved in the induction of immune enhancement of the heart graft survival in rats differing across the major histocompatibility barrier has been studied. Cells devoid of class II antigens on their surface, e.g. erythrocytes, platelets, and thymocytes have been found ineffective, whereas subpopulations rich in class II antigens were found to be highly effective in induction of specific unresponsiveness when combined with donor specific alloserum. Our results suggest that class II antigens take part not only in induction of rejection response but may be also responsible for generation of specific unresponsiveness towards donor antigens.

Animals↗
PubMed1989

Reactivity of normal rat epiphyseal chondrocytes with monoclonal antibodies recognizing different leucocyte markers.

The aim of the study was to test whether normal rat epiphyseal chondrocytes react with monoclonal antibodies (MoAbs) detecting different markers of lymphoid cells. For this purpose, isolated chondrocyte and, for comparison, splenocyte cytosmears were exposed to a battery of different MoAbs followed by indirect immunoperoxidase staining. As we were able to show, all chondrocytes reacted with OX17 MoAb detecting Class II (Ia) antigen encoded by the RT1.D subregion of rat major histocompatibility complex (MHC). However, unlike splenocytes they did not react with OX6 MoAb detecting the RT1.B encoded Class II molecule. Moreover, all chondrocytes were stained with W3/25 MoAb specific for the rat equivalent of human CD4 (T4) antigen and with W3/13 MoAb specific for rat leucocyte sialoglycoprotein. A positive reaction was also obtained with the antibody against the S-100 protein. By contrast, chondrocytes did not react with antibodies specific for all T (OX19) or B (HIS14) cells, rat CD8 (T8) equivalent, monocytes/macrophages (ED1, ED2), factor VIII (M616), or glial fibrillary acidic protein (Z334).

Animals↗
PubMed1987

Expression of class II major histocompatibility complex antigens by bronchial epithelium in rat lung allografts.

Variations in expression of class II major histocompatibility complex antigens on bronchial epithelial cells and vascular endothelium were investigated in normal rat lungs and allografted lungs during acute rejection and after cyclosporine (CsA) treatment. BN (RT1n) left lungs were transplanted into LEW (RT1l) recipients. Lungs were excised during acute rejection in untreated rats on postoperative days 1 through 5, and after CsA treatment (25 mg/kg on days 2 and 3) on days 5 and 100. Cryostat sections were examined for class II antigen expression with an immunoperoxidase technique, using various monoclonal antibodies. In the normal lung, class II antigens were not expressed by epithelial or endothelial cells. In the allografts, induction of class II antigens closely correlated with the rejection process: on day 2, the ciliated bronchial epithelium was locally positive; it became uniformly positive with increasing cellular peribronchial infiltration on days 3 and 4. CsA treatment prevented class II antigen expression to a certain extent, leaving the bronchial epithelium weakly positive at 100 days. Endothelial cells were invariably negative for class II antigens in all allografted lungs. The class II antigens expressed on the bronchial epithelial cells were of graft origin, except for recipient-type class II molecules found on the ciliated surface in CsA-treated animals. We conclude that expression of class II antigens by bronchial epithelium is the result of a bronchus-directed rejection process, and hypothesize that such a rejection process may have caused bronchiolitis obliterans in several of the patients with combined heart-lung transplants. Important is the observation that class II molecules can be present on the membranes of cells that do not themselves produce these antigens.

Animals↗
PubMed1985

The participation of serotoninergic system in the regulation of emotional-defensive behavior evoked by intrahypothalamic carbachol injections in the cat.

The influence of bilateral injections of serotonin (5-HT) and methysergide (MET) to antero-medial hypothalamus (HA) on carbachol-induced emotional-defensive behavior was investigated. Earlier (15 min) stimulation of 5-HT receptors in HA region by 5-HT injections evoked a decrease in the level of vocal response (number and time of growling), while previous blocking of these receptors by means of MET brought about a considerable increase of vocalization level evoked by carbachol (Cch) injections (10 pg) to the same loci of HA. Intrahypothalamic injections of 5-HT alone or MET did not evoke any observable changes in the animals behavior. The alterations of the level of Cch-induced vocal response 3 to 35 days after chemical damage of 5-HT neurons in HA or in the middle forebrain bundle (MFB) in posterolateral hypothalamus caused by 5,7-dihydroxytryptamine were examined. Local neurotoxin injections both to MFB and to HA evoked a long lasting increase in the level of Cch-induced vocalization, which began on the 5th-7th day after lesioning and lasted till the completion of the experiment (35 days). Results data indicate that the 5-HT system exerts an inhibiting influence on the emotional-defensive behavior induced by the cholinergic system.

Aggression↗
PubMed1982

The effects of external stimuli on the emotional-aversive response evoked by intrahypothalamic carbachol injections.

The aim of this investigation was to examine the effects of threatening (the sight and barking of the dog) or "Neutral" (flash and tone) stimuli on the emotional-aversive response evoked by direct intracerebral application of carbachol in cats. Unilateral microinjections of carbachol in 10 microgram doses and 2 mu1 volume into anterior hypothalamic/preoptic area caused a full-blown emotional response with marked vocalization. All stimuli which might be threatening for cats caused a significant increase of vocalization. "Neutral" stimuli of comparable intensity were without effect. To investigate the effects of stimulation intensity two clocks: low and loud (difference of 27 dB), were used. The loud click significantly increased vocalization level while the low click of the same intensity as a dog's barking had no significant influence on the carbachol-induced response. Cholinergic stimulation of the anterior hypothalamic/preoptic area seems to be specifically responsible for the obtained change of perception towards increased sensitivity to any potentially threatening alteration of the environment.

Acoustic Stimulation↗
PubMed1981

Increase in natural fertility during the early stages of modernization: Canadian Indians case study.

It has been hypothesized that populations may experience an increase in their natural fertility during the early stages of modernization as a result of the relaxation of various fertility-inhibiting practices and customs prevalent in traditional societies. This article offers evidence of such an increase in natural fertility among Canadian Indians. The main underlying cause is found to be in the massive, almost abrupt, shift from prolonged breastfeeding to bottlefeeding ;which took place prior to the onset of large-scale birth control practices among Canadian Indians.

Adolescent↗