Human Morphology

Role of Kupffer and parenchymal cells in hepatobiliary clearance of lipopolysaccharides (endotoxins) in perfused rat liver

The purpose of this study is to show and compare the role of Kupffer cells and hepatocytes in ³H-lipopolysaccharide (³H-LPS) clearance at the level of microtubular system after treatment with colchicine and gadolinium chloride (GdCl₃) in perfused rat liver. Forward-binding, reversal-binding, residency-time, and apical-sinusoidal influx rate constants are estimated from the data fittings using the model. GdCl₃ treatment reduced the residency time of ³H-LPS binding to its non-specific receptor on Kupffer cells by » 50% (i =23.26± 2.70 vs 11.90± 0.71 min) but with little effect on parencymal cells. However, colchicine plus GdCl₃ treatments reduced the forward-binding constant by » 56% [1.326± 0.577 vs 0.577± 0.060 (m M.min)^-1] indicating the major role of Kupffer cells in ³H-LPS trafficking and clearance via the canaliculi. A.B. Bikhazi, K.M. Bitar, A.R. Jurjus, K.A. Hassan. (Supported by LNCSR.)

Potential alteration of the binding kinetics of angiotensin II receptors and the effect of angiotensin receptor subtype 2 activation in rat myocardial infarction model

The present study assesses the binding kinetics of angiotensin II (AngII) on its various receptor subtypes in acute myocardial infarction (AMI) rat models. An already established mathematical model will be employed, to measure the AngII binding in the rat groups mentioned below and explain the effects of AngII-receptor subtype 2 (AT₂-R) activation in various AMI rat models. AMI is induced in intubated Sprague-Dawley female rats, by performing ligation of the left anterior descending coronary artery. One month after AMI, a heart perfusion technique will be performed where each group will be perfused by radiolabeled angiotensin II (125I-Sar1-Ile8) to assess affinity and binding on the coronary endothelium and myocytes. The receptors of different cell types at various heart regions will be qualitatively and quantitatively determined. A.B. Bikhazi, K.A. Hassan, A.R. Jurjus. (Supported by DTS Fund.)

Hypertension is a well-recognized pathophysiological contributor to the progression of coronary artery disease. We study the role of cell-cell communication in the control of vasomotor function and develop strategies for prevention and effective intervention in pathological situations. We study the role of gap junction channels formed between endothelial cells (EC) and smooth muscle cells (SMC) in transferring regulatory components, produced by EC, to SMC. The advantage of direct transfer of effectors is that it circumvents the dilution to inactive concentrations in the extracellular compartment and to initiate locally confined response of SMC. We use confocal imaging microscopy and flowcytometry to study gap junctions between EC and SMC in purified cell cultures of EC and SMC and in cocultures of the two. An understanding of normal coordination of vasomotor function by cell-cell communication is necessary for the task of unraveling the basis of altered regulation in disease. M. El-Sabban (Supported by LNCSR, URB, DTS Fund, and MPP.)

Cutaneous T-cell lymphomas (CTCL): mechanisms of homing to the skin and interaction with its microenvironment

The epidermotropic nature of Cutaneous T-Cell Lymphoma (CTCL) poses the question related to the mechanisms by which these cells specifically adhere to vascular endothelial cells in the skin, their ability to extravasate and the modalities by which these cells interact with resident cells in skin. We are studying the homing of normal T lymphocytes, and neoplastic lymphocytes cells to microvessel endothelial cells derived from skin. Also, we studadhesion and communication of lymphocywith Langerhans cells and with normal keratinocytes. We will test the in vivo proven effective treatments of Adult T Cell Leukemia (ATL) and Adult Promylocytic Leukemia (APL), Interferon-a (IFN-a ), zidovudine (AZT), Arsenic (As), retinoic acid (RA) and their combination on adhesion and communication properties of these cells and their interaction with their microenvironment. Understanding these mechanisms will allow us to formulate strategies to modulate interaction with resident skin cells in an effort to prevent CTCL dissemination. M. El-Sabban, A. Bazarbachi, A.G. Kibbi, N. Rubeiz. (Supported by Terry Fox Cancer Fund.)

Morphological alterations in the carotid body and sinus of primary and secondary hypertensive rats, and assessment of the humoral basis of such alterations

The structural changes in the carotid body and sinus of animals having spontaneous hypertension but not secondary, nephrogenic, hypertension have been studied. Humoral factors as well as changes in nitric oxide could constitute a possible basis for such alterations. Spontaneously hypertensive rats (SHR's) and normal Wistar Kyoto rats with renovascular stenosis (2K, 1C) will be used as models for primary and secondary hypertension respectively. Blood pressure, body weight as well as other parameters will be monitored periodically. Tissue biopsies from formalin perfused animals will be removed, fixed and processed for light microscopy, immunohistochemistry, and confocal microscopy. The tissue removed will include the carotid body and sinus, blood vessels, and kidneys. Anti-peroxynitrite, anti-cytokeratin, anti substance P, and anti-integrins, antibodies will be used, and findings correlated with morphological alterations. A.R. Jurjus, H. El-Khansa*, A. Birbari. (Supported by DTS Fund.)

Hyperalgesia induced by cutaneous leishmaniasis and its modulation by thymulin

Murine Cutaneous Leishmaniasis (C.L.) induced by leishmania major, produced hyperalgesia and increased levels of interleukin 1b (IL-1b ) and nerve growth factor (NGF). In this study, we investigate whether daily injections of thymulin can alter the hyperalgesia and the increased levels of cytokines by C.L. BALB/c mice received intraplantar injections of either Leishmania prosmostigote only, or Leishmania followed by daily injections of thymulin, then subjected to acute pain tests or sacrificed at various time intervals for the determination of cytokines by ELISA. Treatment with thymulin reduced, in a dose-dependent manner, the hyperalgesia induced by C.L. These injections also reversed the increased levels of IL-1b and NGF. High doses of thymulin could reverse the hyperalgesic effects of C.L., by down regulating the levels of IL-1b and NGF. A. Jurjus, N. Saadé, H. Khansa*, B. Safieh-Garabedian, S. Kanaan. (Supported by URB.)

Changes in the level of tumor necrosis factor alpha (TNFa ) and its receptor in the blood and follicular fluid of polycystic ovarian patients

Polycystic ovary (PCO) is a symptom complex. TNFa produced by follicular cells is thought to act as an anti-differentiative factor in granulosa cells. Dexamethasone suppresses TNFa levels in PCO follicular fluid and when added to the medical treatments, stimulates ovulation in gonadotropin resistant infertile women. The overall objective of this study is to examine the role of TNFa in determining the fate of the ovarian follicle. Human ovaries, granulosa and theca cells and follicular fluid from NOW and PCO patients will be examined in vivo and in vitro to study the involvement of TNFa in the development of PCO. Experimental analysis will include biochemical, molecular and immunohistochemical techniques. Human tissue specimens will be obtained from subjects undergoing treatment for infertility. These studies are expected to demonstrate the role of TNFa in the regulation of development of the ovarianfollicle and form the basis for future investigations on new modality of treatment of PCO. E. Karkaji*, S. Nasr, C. Tarraf, J. Awwad, A. Jurjus. (Supported by LNCSR.)

On the human host: more isolates are obtained for characterization in the animal model and by isoenzyme profile. On the reservoir animal: Identification of carrier animals in different foci in Lebanon by:

On the vector: Completion of transects and in depth study of one focus. N. Nuwayri-Salti, K. Knio, E. Abu Fakhr, E. Baydoun, Z. Shbaklo. (Supported by LNCSR.)

Investigations on polymorphic genomic markers in relation to applied field research on the biology of Leishmania parasites in various eco-epidemiological settings in the Mediterranean basin

Part one of this project is close to conclusion. In depth study of a major focus.

Finally, in depth sequential study of the vector (endophilic and exophilic) to try to determine the transmission cycle. N. Nuwayri-Salti, J.C. Dujardin, I. Guizani, J.P. Dedet. (Supported by European Commission.)

Immunogenetic markers associated with some autoimmune disorders (Behçet's Syndrome)

Immunogenetic markers of class I HLA antigens in patients with Behçet's syndrome. (serologic study). HLA-B51 allele is associated with Behçet's disease in several populations but its importance in disease complications is not well studied. We analyzed the HLA typing in 46 Lebanese patients diagnosed to have Behçet's disease according to the International Study Group criteria. Twenty eight percent were HLA-B51 positive compared to 15.5% in our general population (p=0.04). Anterior and/or posterior uveitis was present in 15/31 (48%). In the HLA-B51 positive group, the frequency of uveitis was 87% (7/8) compared to 35% (8/23) in the HLA-B51 negative group (p=0.01) suggesting a strong association. No statistically significant difference was seen in venous, arterial or neurological complications between the two groups. In addition, patients with HLA-B51 allele have at least one major complication (uveitis, venous, arterial or neurological) compared to HLA-B51 negative patients (p=0.036). This study provides additional evidence that Behçet's disease is associated with HLA-B51 allele in the Lebanese population and suggests that HLA-B51 allele may have a prognostic value in patients with Behçet's disease. N. Nuwayri-Salti, I. Uthman, F. Nasr. (Supported by AUB URB.)

Contribution of someimmune mechanisms to the pathogenesis of essential hypertension

Cellection of data and tissue (thymus) samples from patients with hypertension and appropriate controls. Preliminary findings on thymic tissue by routine H and e staining reveal an unusual population of cells. Immuno-fluorescence will be used at a later stage. M. Obeid, W. Mudawar, N. Nuwayri-Salti. (Supported by MPP.)

Effects of injuries to peripheral and central somatic sensory pathways in the processing of nociceptive information and pain

This work aims at unraveling short and long-term plastic changes in the central nervous system produced by injury to peripheral and/or central somatic sensory pathways and hopefully leading to a better understanding of the neural mechanisms of chronic pain. N. E. Saadé, S.F. Atweh, S.J. Jabbur. (Supported by URB and Diana Tamari Sabbagh Funds.)

Activation of brainstem pain modulatory centers by dorsal column stimulation: role of descending serotonergic pathways

Most of the clinical and research reports agree about the analgesic effects of the dorsal column (DC) stimulation, but there is no unanimity about the neural mechanisms involved in this stimulation. The aim of the present study is to compare the effects of antidromic and rostral activation of the DCs and to investigate whether these effects are mediated through a brainstem spinal loop. N.E. Saadé, S.F. Atweh, S.J. Jabbur, A. Privat*. (Supported by Franco-Lebanese CEDRE.)

These studies include the use of capsaicin, formalin and the recent introduction of a new model wbacterial endotoxin to induce inflammatory pain. Work continues towards understanding of the peripheral mechanisms of these models and to use them for assessing various forms of thermal and mechanical hyperalgesia in animals. N.E. Saadé, S.J. Jabbur, S.F. Atweh. (Supported by URB.)

The thalamus continues to be regarded as a most important structure for the perception of pain. However, several clinical studies have shown that thalamic lesions can produce pain and thalamic stimulation can relieve chronic pains. The mismatch between the traditional view and the clinical data led to a paradox: how can a function carried by a neural structure be reduced when that structure is stimulated and exaggerated when that structure is ablated. Our experimental data provide an alternative view for the role of the thalamus in the processing of nociceptive information and pain. N.E. Saadé, S.J. Jabbur, S.F. Atweh. (Supported by URB.)

Effects of selective chemical lesions placed in the basl ganglia on pain-related behavior

Previous work from our laboratory has shown that surgical and/or chemical lesions of either the cerebral cortex or the striatum produced significant inhibition of autotomy behavior (model for chronic deafferentation pain) and nociceptive reflexes (models for acute pain) in rats. Thdata provided experimental evidence on the role of the basal ganglia in the processing of nociceptive information and their involvement in the control of pain-related behavior. Furthermore, these results provide neural substrates to the recent clinical observation showing an involvement of the neostriatum in the frontal lobe syndrome. N.E. Saadé, S.J. Jabbur, S.F. Atweh. (Supported by URB and DTS Fund.)

Hyperalgesia induced by local inflammation: upregulation of cytokines and neurotrophins and induction of fos-like immunoreactivity in the central nervous system

Intraplantar and intraperitoneal injections of inflammatory or proinflammatory agents produce hyperalgesia as assessed by various acute pain tests. This hyperalgesia is characterized by an increase in the levels of interleukin 1b , tumor necrosis factor and nerve growth factor in the peripheral tissues. These peripheral events play a major role in the induction of fos gene expression at the level of the central nervous system and especially in specific areas known to be involved in the processing of nociceptive information. N.E. Saadé, B. Safieh-Garabedian, S. Kanaan, S.F. Atweh, S.J. Jabbur. (Supported by URB and DTS Fund.)

The identification and documentation of the anatomic variations in muscles and vessels are helping to clarify and expand our incomplete knowledge of the structure of the human body. The ongoing project is a micro/mascroscopic study of selected cadaveric material, previous findings having already been published. F. Saadeh, R. Bergman*, F. Haikal*, J. Hawi. (Supported by Dept. of Human Morphology; Dept. of Anatomy, Alexandria University through F. Haikal.)

A thorough knowledge of vascular patterns in myocutaneous and fasciocutaneous flaps used in reconstructive surgery is extremely important. The ongoing anatomic study evaluates the vascular basis for such flaps, especially vessels that traditionally receive little attention in didactic teaching, but could be invaluable to the surgeon. F. Saadeh, F. Haikal*, M. El-Sabban. (Supported by Anatomy Dept., University of Alexandria through F. Haikal.)

Bahuth, N., Abou Jaoude, P.G., Saadeh, F., Hamoui, S., Safieh-Garabedian, B., Kanaan, S.A., Jabbur, S.J., Saadé, N.E., Intraplantar endotoxin (ET) injection induces fos like immunoreactivity in the lumbar spinal cord of rats. Society for Neuroscience, 23, 1803, 1997.

Bahuth, N., Makki, A.A., Atweh, S.F., Saadé, N.E., Jabbur, S.J., Modulation of the dorsal column nuclear (DCN) activities by cerebellar inputs. Society for Neuroscience, 24, 2081, 1998.

Barada, K.A., Saadé, N.E., Atweh, S.F., Nassar, C.F., Intravenous and intracerebral injection of calcitonin gene related peptide inhibits amino acid absorption across the rat jejunum. Digestion, Supplement 3, 65, 1998.

Bazarbachi, A., El-Sabban, M.E., Nasr, R., Quignon, F.*, Awaraji, C., Kersual, J.*, Dianoux, L.*, Haidar, J., Hermine, O.*, De Thé, H.*, Arsenic trioxide and interferon-a synergize to induce cell cycle arrest and apoptosis in HTLV-I transformed cells. Blood, 93, 279-283, 1999.

Bejjani, G.K.*, Sullivan, B.*, Salas-Lopez, E.*, Abello, J.*, Wright, D.C.*, Jurjus, A., Sekhar, L.N.*, Surgical anatomy of the infratemporal fossa: the styloid diaphragm revisited. Neurosurgery, 43 (4), 842-852, 1998.

Correa, R.*, Jurjus, A., Walsh, R.*, A bilateral double axillary artery: embryological basis and clinical implications. The FASEB Journal, 11 (3), 1494/ p.257, 1997.

Das, S.*, Horowitz, S.*, Robbins, C.*, El-Sabban, M.E., Sahgal, N.*, Davis, J.M.*, Intracellular uptake of recombinant superoxide dismutase after intratrachael administration. American Journal of Physiology, 18, L673-L677, 1998.

El-Assaad, W., El-Sabban, M.E., Awaraji, C., Abboushi, N., Dbaibo, G., Distinct sites of action of Bc1-2 and Bc1-x1 in the tumor necrosis factor TNF-a ceramide pathway of apoptosis. Journal of Biochemistry, 366, 735-741, 1998.

El-Sabban, M.E., Martin, C.A.*, Homaidan, F.R., Signaling between immune cells and intestinal epithelial cells in vitro. Gap Junctions, 178-182, 1998.

Haddad, R., Jurjus, A., Ibrahim, M., Nahlé, Z., El-Kasti, M., Bitar, K., Kreydiyyeh, S., Saadeh, F., Bikhazi, A., Binding of 125I-insulin on capillary endothelial and myofiber cell membranes in normal and streptozotocin diabetic perfused rat hearts. Journal of Comparative Biochemistry and Physiology, A117 (4), 523-530, 1997.

Hajj-Ali, R., Arayssi, T., Nasr, F., Nuwayri-Salti, N., HLA typing in Lebanese behçet patients. Arthritis and Rheumatism, 41 (9), 550, September 1998.

Jabbur, S.J., Atweh, S.F., Safieh-Garabedian, B., Kanaan, S.A., Saadé, N.E., A possible involvement of meso-striato-limbic structures in pain modulation. In Pain Mechanisms and Management, ed. Apkarian, A.V. and Ayrapetian, S., 164-180. Ohmsa, Armenia: IOS Press, 1998.

———, Alteration of endotoxin (ET)-induced hyperalgesia by chronic and acute treatment with capsaicin (CP). Society for Neuroscience, 24, 383, 1998.

Jurjus, A., Hospitalization and heavy medical technology utilization in Lebanon. Lebanese Studies, 7/8, 45-60, 1997/98.

———, Assessment of AIDS knowledge, attitudes, behaviors and occupational risk of laboratory personnel in Lebanon. Lebanese Medical Journal, 46 (5), 285-290, 1998.

Jurjus, A., Correa-de-Araujo, R.*, Bohn, R.C.*, A bilateral double axillary artery: embryological basis and clinical implications. Clinical Anatomy, 12, 135-140, 1999.

Jurjus, A.R., Karam, M., Khansa, H.*, Saadé, N., Kanaan, S.A., Thymulin injections modulate the hyperalgesia and the upregulation of cytokine levels induced by cutaneous leishmaniasis. The FASEB Journal, 13 (4 add.),LB112, 1999.

Jurjus, A., More, N.*, Walsh, R.J.*, Detection of substance P positive cells and nerve fibers in the rat thymus. Journal of Neuroimmunology, 90 (2), 143-148, 1998.

Jurjus, A., Walsh, R.J.*, Detection of substance P positive cells and nerve fibers in the rat thymus. The FASEB Journal, 11 (3), 1168/A201, 1997.

Jurjus, A., Walsh, R.J.*, Weglicki, W.B.*, Correa-de-Araujo, R.*, Increase in the expression of substance P receptors in the atria of magnesium-deficient rats. Cardiovascular Pathobiology, 2 (3-4), 199-206, 1998.

Kanaan, S.A., Poole, S., Saadé, N.E., Jabbur, S.J., Safieh-Garabedian, B. Interleukin-10 reduces the endotoxin induced hyperalgesia in mice. Journal of Neuroimmunology, 86, 142-150, 1998.

Kanaan, S.A., Safieh-Garabedian, B., Haddad, J.J., Atweh, S.F., Abdelnoor, A.M., Jabbur, S.J., Saadé, N.E., Effects of various analgesic and anti-inflammatory drugs on endotoxin-induced hyperalgesia in rats and mice. Pharmacology, 54, 285-297, 1997.

Kanaan, S.A., Safieh-Garabedian, B., Jurjus, A.R., El-Khansa, H.F.*, Saadé, N.E., Hyperalginduced by cutaneous leishmaniasis and its modulation by thymulin. Journal of Neuroimmunology, 90 (13), 105, 1998.

Mangurian, L.*, Jurjus, A.R., Karas, K.*, Walsh, R.J.*, Prolactin receptor localization to the area postrema. The FASEB Journal, 12 (5), 3983/ A687, 1998.

Martin, C.A.*, El-Sabban, M.E., Zhao, L.M.*, Homaidan, F.R., Adhesion and cytosolic dye transfer between macrophages and intestinal epithelial cells. Cell Adhesion and Communication, 5, 83-95, 1998.

Martin C.A.*, Homaidan, F.R., Burakoff, R.*, El-Sabban, M.E., Heterocellular communication through gap junctions between intestinal epithelial cells and macrophages. Cell Adhesion and Communication, 5, 437-449, 1998.

Maesaka, J.*, Palaia, T.*, Chowdhury, S.*, Shimamura, T.*, Fishbane, S.*, Reichman, W.*, Coyne, A.*, El-Sabban, M.E., Partial characterization of apoptotic plasma factor in Alzheimer's disease. American Journal of Physiology, 276, F521-F527, 1999.

Nuwayri-Salti, N., Arayssi, S., Sleiman, H., Naddaf, M.*, Usta, J., Chamat, S., Fakhoury, R.*, Knio, K.*, Cutaneous leishmaniasis in Syria Lattakujeh Governorate immune response in the clinical types in two different biotopes. American Journal of tropical Medicine and Hygiene, 59 (3 [supplement]), 200, 1998.

Nuwayri-Salti, N., Baydoun, E., Tannir, D., Arayssi, S., Knio, K., Profile of leishmaniasis in Lebanon: review of patients with cutaneous disease referred to American University of Beirut. American Journal of Tropical Medicine and Hygiene, 57 (228), 178, 1997.

Nuwayri-Salti, N., Chaya, M.*, MHC class I antigen expression in the Lebanese population. WHO-Eastern Mediterranean Health Journal, 3 ( 1), 101-107, 1997.

Nuwayri-Salti, N., Haddad, K., Chamat, S., Usta, J., Canine leishmaniasis in northern Lebanon. Annals of Tropical Medicine and Parasitology, 91 (2), 221-222, 1997.

Nuwayri-Salti, N., Matta, M., Shbaklo, Z., Lakkis, M., El-Jisr Kabbani, Z.*, Behavior in a mouse model of isolates of Leishmania donovani sensuo lato cultured from the blood of patients with chronic lesions. The American Journal of Tropical Medicine and Hygiene, 58 (6), 710-714, 1998.

Nuwayri-Salti, N., Nasr, R., Shbaklo, Z., Malek, J., Direct transmission of Leishmania donovani in the absence of cutaneous lesions among mated mice. Acta Parasitologica Turcica, 21 (Supplement [1]), 159, 1997.

Saadé, N.E., Abou Jaoude, P.G., Saadeh, F.A., Hamoui, S., Safieh-Garabedian, B., Kanaan, S.A., Atweh, S.F., Jabbur, S.J., Fos-like immunoreactivity induced by intraplantar injection of endotoxin and its reduction by morphine. Brain Research, 769, 57-65, 1997.

Saadé, N.E., Atweh, S.F., Bahuth, N., Jabbur, S.J., Augmentation of nociceptive reflexes and chronic deafferentation pain by chemical lesions of either dopaminergic terminals or midbrain dopaminergic neurons. Brain Research, 751, 1-12, 1997.

Saadé, N.E., Kanaan, S.A., Haddad, J.J., Atweh, S.F., Jabbur, S.J., Safieh-Garabedian, B., Dissociation between peripheral and central components of endotoxin-induced hyperalgesia. In Pain Mechanisms and Management, ed. Apkarian, A.V. and Ayrapetian, S., 120-130. Ohmsa, Armenia: IOS Press, 1998.

Saadé, N.E., Lawand, H.F., Safieh-Garabedian, B., Kanaan, S.A., Atweh, S.F., Jabbur, S.J., Intraplantar (i.pl.) injection of thymulin induce fos expression in the spinal cord (SC), its reversal by morphine. Journal of Neuroimmunology, 90 (13), 105, 1998.

Saadé, N.E., Major, S.C., Jabbur, S.J., Atweh, S.F., Kanaan, S.A., Safieh-Garabedian, B., Involvement of capsaicin sensitive primary afferents in thymulin-induced hyperalgesia. Journal of Neuroimmunology, 91, 171-179, 1998.

Saadeh, F.A., Haikal, F.A.*, Abdel-Hamid, F.A.M.*, Blood supply of the tensor fasciae latae muscle. Clinical Anatomy, 11 (4), 236-238, 1998.

Saadeh, F.A., Kawas, S.H.*, Haikal, F.A.*, Hawi, J.S., An unusual levator glandulae thyroideae: a case report and literature review (this 1996 article was missed in 22^nd Research Report). Journal of the Anatomical Society of India, 45, 125-128, 1996.

Safieh-Garabedian, B., Jalakhian, R.H., Jabbur, S.J., Saadé, N.E., Kanaan, S.A., Thymulin at high doses reduces endotoxin-induced hyperalgesia by reducing interleukin-1b and nerve growth factor levels in the hind paw of rats. In Pain Mechanisms and Management, ed. Apkarian, A.V. and Ayrapetian, S., 131-138.Ohmsa, Armenia: IOS Press, 1998.

Safieh-Garabedian, B., Kanaan, S.A., Atweh, S.F., Jabbur, S.J., Saadé, N.E., Intraperitoneal thymulin injections produce hyperalgesia mediated through prostaglandin (PGE2) mechanisms and vagal afferents. Society for Neuroscience, 24, 2078, 1998.

Safieh-Garabedian, B., Kanaan, S.A., Haddad, J.J., Abou Jaoude, P., Jabbur, S.J., Saadé, N.E., Involvement of interleukin-1b , nerve growth factor and prostaglandin-E₂ in endotoxin induced localized inflammatory hyperalgesia. British Journal of Pharmacology, 121, 1619-1626, 1997.

Safieh-Garabedian, B., Kanaan, S.A., Jabbur, S.J., Atweh, S.F., Saadé, N.E., The contribution of tumor necrosis factor-a , (TNF-a ) interleukin-1b (IL-1b ) and nerve growth factor (NGF) to thymulin induced hyperalgesia. Society for Neuroscience, 23, 719, 1997.

Safieh-Garabedian, B., Kanaan, S.A., Jabbur, S.J., Saadé, N.E., Cytokine mediated or direct effects of thymulin on the nervous system as assessed by pain related behavior. Neuroimmunomodulation, 6, 39-44, 1999.

Safieh-Garabedian, B., Kanaan, S.A., Jalakhian, R.H., Jabbur, S.J., Saadé, N.E., Involvement of interleukin-1b , nerve growth factor and prostaglandin-E₂ in the hyperalgesia induced by intraplantar injections of low doses of thymulin. Brain, Behavior and Immunity, 11, 185-200, 1997.

Safieh-Garabedian, B., Kanaan, S.A., Jalakhian, R.H., Poole, S.*, Jabbur, S.J., Saadé, N.E., Hyperalgesia induced by low doses of thymulin injections: possible involvement of prostaglandin E₂. Journal of Neuroimmunology, 73, 162-168, 1997.

Talhouk, R.S., Abou-Gergi, R.G., Mouneimne, G., Saadé, N.E., Safieh-Garabedian, B., Growth hormone releasing hormone (GHRH) reduces significantly endotoxin (ET)-induced localized inflammatory hyperalgesia in mice. Society for Neuroscience, 24, 638, 1998.

Talhouk, R., Hajjar, L., Abou-Gergi, R., Saadé, N.E., Safieh-Garabedian, B., Modulation of hyperalgesia and ECM-degrading proteinases in an endotoxin mediated local and reversible acute inflammation. Society for Neuroscience, 23, 1808, 1997.

Atweh, S.F., Saab, C.Y., Jabbur, S.J., Saadé, N.E., The effects of thalamic lesions on acupain tests in rats. 2^nd Congress of European Federation of IASP Chapters, 134, Barcelona, Spain, 1997.

El-Sabban, M.E., Homo- and hetero-cellular gap junction communication in the vasculature: implications for vasomotor function. International Meeting on Gap Junctions, Rio de Janeiro, Brazil, 1998.

El-Sabban, M.E., Nasr, R., Quignon, F.*, Hermine, O.*, De Thé, H.*, Bazarbaachi, A., Induction of cell cycle arrest and apoptosis in HTLV-I transformed cells by a combination of arsenic trioxide and interferon-a . International Conference on HTLV-I, Kagoshima, Japan, 1998.

El-Sabban, M.E., Kalaany, N., Shami, R., Shaito, A., Bassam, R., Talhouk, R., Modulation of gap junctional protein expression and function in CID-9 mammary cells by extracellular matrix. The Gordon Conference, New Hampshire, USA, 1999.

Gali-Muhtasseb, H.U., Al Maalouf, S., Darwiche, N., Hazimeh, Y., El-Sabban, M.E., In vitro effects of vitamin E and analogue on UVB-induced apoptosis. AACR Meeting, Philadelphia, USA, 1999.

Hajj-Ali, R., Arayssi, T., Nasr, F., Nuwayri-Salti, N., HLA typing in Lebanese behçet patients. International Congress on Arthritis and Rheumatism, San Diego, California, September 1998.

Homaidan, F.R., El-Assaad, W., Chakroun, I., Dbaibo, G., El-Sabban, M.E., IL-1 increases ceramide production and induces COX-2 in intestinal epithelial cells. Annual Meeting of the American Gastroenterological Association, New Orleans, USA, 1998.

Homaidan, F.R., Martin, C.A.*, El-Sabban, M.E., Signaling between immune cells and intestinal epithelial cells in vitro. International Gap Junction Conference, Key Largo, USA, 1997.

Jurjus, A.R., Evaluation of HIV/AIDS prevention efforts among Lebanese. 12^th World AConference, Geneva, Switzerland, 1998.

Nuwayri-Salti, N., Isoenzyme characterization of leishmania isolates from Lebanon and Syria. The 46^th Annual Meeting of the American Society of Tropical Medicine and Hygiene, 57 number 3 Supplement (229), 179, Orlando, Florida, 1997.

———, Immune response to the causative agent Leishmania donovani in Lebanese patients with cutaneous leishmanisis. The 3^rd International Workshop on Molecular Epidemiology and Evolutionary Genetics of Infectious Diseases - MEEGID-3, 18, 63, Rio de Janeiro, Brazil, 1998.

———, Pathogenesis of autoimmunity. The IVth Makassed Medical Congress on Autoimmunity, Beirut, Lebanon, 23-26 September 1998.

———, Non-phlebotomine transmission of Leishmania parasites. First World Congress on Leishmanioses, Istanbul, Turkey, 1997.

———, HLA class II markers in Lebanese patients with insulin dependent diabetes mellitus. The 1^st Syrian-Lebanese Congress on Diabetes, The Sixth Syrian Congress on Diabetes, Aleppo, Syria, 17-19 September 1997.

———, The genetics of medullary carcinoma of the thyroid. The Third Annual Meeting of the Syrian Endocrine Society, Bosrah, Syria, 1997.

———, Prevalence of seropositivity to antigens from different Leishmania species in normal and immunosuppressed subjects. IXth International Congress of Parasitology (ICOPA IX), Chiba, Japan, 1998.

———, Epidemiology of leishmaniasis in Lebanon. Workshop on new Trends in Leishmaniasis Epidemiology and Control in the Mediterranean Area, Palermo, Italy, 1997.

Nuwayri-Salti, N., Arayssi, S., Sleiman, H., Naddaf, M.*, Usta, J., Chamat, S., Fakhoury, R.*, Knio, K.*, Cutaneous leishmaniasis in Syria Lattakujeh Governorate immune response in the clinical types in two different biotopes. 47^th Annual Meeting of the American Society of Tropical Medicine and Hygiene, San Juan - Puerto Rico, 1998.

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