Research Projects
Bacterial endotoxin (LPS) The
effect of human hemoglobin on some of the biological activities of LPS
is being investigated. Hemoglobin enhanced the LPS-induced gelation of
limulus amebocyte lysate, increased the binding of LPS to the CD14 receptor
on human monocytes, slightly depressed LPS-induced 1L-1 beta production
by human peripheral mononuclear cells; and blocked the ability of LPS to
activate the alternate ane classical pathways of the complement system.
Antihemoglobin antibodies prepared in rabbits appeared to neutralize the
hemoglobin-induced limulus lysate gelation, and partially blocked hemoglobin-LPS
binding to the CD14 receptor on monocytes. The significance of this study
is related to attempts to determine the mechanism(s) of action of LPS in
order to introduce means to neutralize its effects. A. M. Abdelnoor.
(Supported by URB.)
HLA frequencies in Lebanese HLA
frequencies in a number of Lebanese demographic groups are being determined.
Disease associations and alleles in linkage disequilibrium are also being
investigated. HLA Class I antigens are being detected by the micro-cytotoxicity
assay and HLA Class II antigens by both the microcytotoxicity assay and
DNA typing (PCR). A. M. Abdelnoor. (Supported by LNCSR.)
Anti-bacterial effects of the constituents of Nigella sativa oil Nigella
sativa oil inhibited the growth of gram positive organisms in vitro.
The composition of the oil was determined by gas liquid chromatography
and the different constituents were tested for their anti bacterial effect.
Two of the constituents, linolenic acid and thymoquinone were shown to
have anti-bacterial activity. Minimum Inhibitory Concentrations (MIC) have
been determined and in vivo studies using mice have been initiated.
A. M. Abdelnoor. (Supported by Deptartment of Microbiology and Immunology.)
Genotyping of HIV isolated from patients in Lebanon Twenty-six
HIV isolates from patients in Lebanon have been genotyped. Ten belonged
to HIV-1 subtype A and 10 to subtype B. Work in progress deals with genotyping
the remaining 6 isolates which did not belong to subtypes A or B. A.
M. Abdelnoor, G. Matar, J. Moukhbat, M. Uwaydah and W. Heneine*.
(Supported by Center for Disease Control.)
Identification of allergens in patients with allergic asthma We
previously reported that the identified allergen in 16 of 60 patients with
allergic asthma was the dust mite. Other allergens were identified in 7
of 60 patients. No allergen was identified in 37 of 60 patients. Work in
progress includes broadening our panel of allergens in an attempt to identify
allergens for all patients. The results of this study are of epidemiological
and clinical significance. A.M. Abdelnoor and F. Ramadan.
(Supported by Department of Microbiology and Immunology.)
Humoral immunity in tuberculosis Humoral
immunity in patients with tuberculosis is being assessed. Anti mycobacterial
antibodies, circulating immune complexes, immunoglobulin levels and complement
levels and activity are being measured in serum specimens obtained from
patients and appropriate controls. The significance of the results of this
study is related to the laboratory diagnosis, prognosis and possibly pathogenesis
of tuberculosis. A. M. Abdelnoor, F. Ramadan and M. Naboulsi
Khalil. (Supported by AUB Medical Practice Plan; Faculty of Medicine.)
Development of human monoclonal antibodies specific for varicella zoster virus The
aim of this study is to generate human neutralizing monoclonal antibodies
(Mabs) specific for varicella-zoster virus (VZV) for the treatment of serious
VZV infections and the prophylaxis of susceptible contacts. Available treatments
include passive immunotherapy with high titer human immunoglo(VZIG). Monoclonal
human antibodies are more homogeneous and more specific than VZIG and constitute
a substantial therapeutic progress in the treatment of varicella complications
and the control of VZV contagion. We intend to generate human anti-VZV
Mabs by using a combination of in vitro stimulation of human splenocytes
followed by in vivo boost after reconstitution of severely combined
immunodepressed (SCID) mice. This unique method has previously resulted
in the development in the SCID mouse recipient of abdominal tumors that
secrete specific antibodies to the antigen. Such tumors will be excised
and cultured. Specificity of the secreted antibodies will be assessed against
purified antigen and VZV infected cells. S. Chamat. (Supported in
part by AUB Medical Practice Plan.)
Development of monoclonal antibodies to a copper-stimulated ATPase A
P-type ATPase activated by copper (Cu-ATPase) is involved in cooper transport
disorders that characterize Wilson and Menkes diseases. A Cu-ATPase activity
has been identified and enriched by purification of rat liver membrane
extract. Monoclonal mouse antibodies may be a valuable tool for localizing
this protein in tissues and understanding the linkage between the enzyme’s
distribution, abundance and activity on one hand and the severity of copper
transport disorder on the other hand. We have immunized mice with the Cu-ATPase
enriched rat liver fraction and generated high specific antibody titers.
Preliminary results suggest the presence of anti-Cu-ATPase antibodies in
the polyclonal response since the pre-incubation of Cu-ATPase enriched
fraction with immune serum partially inhibits Cu-ATPase activity. A large
number of monoclonal antibodies were subsequently generated. Western Blot
analysis shows that antibodies are directed against various proteins of
the liver extract. We are currently investigating the capacity of these
monoclonals to modulate ATPase activity. S. Chamat, C. Bishara, J. Usta
and N. Cortas. (Supported by AUB Medical Practice Plan.)
Evaluation of humoral immunity to viral pathogens among Filipino and Lebanese hospital staff To
help prevent the spread of nosocomial infections within the AUB medical
staff, we investigated the protection status of Lebanese and Filipino nurses
and medical students against measles, mumps and varicella-zoster. Sera
were screened for specific IgG antibodies against measles, mumps and varicella
zoster. The subjects filled out a medical questionnaire that allowed us
to compare protection status according to ethnic background, age at time
of infection and years of practice. No difference was observed between
the seropositivity of the Filipino and Lebanese nurses against measles,
mumps and varicella-zoster viruses, in contradiction with previous studies,
but a statistically significant difference was observed for the age at
time of infection with varicella zoster: 16 years for Filipinos versus
7 years for Lebanese. Overall, the seropositivity rates of the nurses were
higher than those of first year medical students, suggesting that subclinical
infections might occur due to exposure to patients. S. Chamat, A. Khayat,
N. Nassar and A. Abdelnoor.
Human monoclonal antibodies specific for the fusion protein of respiratory syncitial virus derive from spontaneous EBV transformed tumors of hu-SCID mice Using
a novel approach combining in vitro antigen priming of human splenocytes
with in vivo boost after their reconstitution in SCID mice, we generated
spontaneous tumors of human origin that readily secreted anti-respiratory
syncitial virus monoclonal antibodies inhibiting virus infectivity in culture.
In this study we demonstrate that these tumors express the late membrane
protein, an EBV antigen present in EBV transformed cell lines. Other investigators
have reported the development of similar abdominal tumors in SCID mice
and shown that they were due to spontaneous EBV transformation of the human
cells, but they had no defined specificity. This is the first report of
spontaneous EBV transformation of antigen specific cells in SCID. On the
other hand, both antibodies bind to closely related epitopes and preliminary
results suggest that they exert their inhibitory effect by preventing virus
fusion to its target cell. Neither of the antibodies seems to mediate complement
activation or antibody dependant cytotoxicity. S. Chamat, M. Usta, C.
Awaraji and P. Brams*.
PCR-identification of the etiology of bacterial meningitis in CSF specimens of infected patients We
developed a PCR-based assay for the detection and identification of the
etiology of bacterial meningitis directly in CSF specimens. Bacterial DNA
was detected using a set of universal primers that flank a “370” bp sequence
conserved among all bacteria. Specific identification of bacteria was done
using species-specific primers. These primers are complementary to a variable
region within the “370” bp conserved sequence. Our data have shown that
of 19CSF specimens collected from patients suspected clinically to have
bacterial meningitis, 9 (42%) were positive by PCR. Seven of these cases
were identified by species specific PCR to be Haemophilus influenzae,
and one was Streptococcus pneumoniae. Culture studies have shown
that 2(25%) positive by PCR were positive by culture. PCR negative results
were culture negative. G. M. Matar, W. Aboul Khoudoud, M. Fayad, M.
Mikati and A. Abdelnoor.
PCR-detection of Bacillus cereus diarrheal enterotoxin genes: comparison with commercial toxin detection kits We
developed a polymerase chain reaction (PCR)-based assay for the detection
of Bacillus cereus diarrheal enterotoxin gene by the amplification
of a 310-bp target sequence. A total of 27 strains obtained from outbreak
studies and food products were examined by our PCR assay and two commercially
available toxin detection kits: TECRA (ELISA) and BCET RPLA (reversed passive
latex agglutination). Most isolates positive by PCR were RPLA positive
(3 negative) and all that were PCR negative were RPLA negative. This indicates
that there is an 81% correlation between PCR and RPLA results. The 3 PCR
positive, RPLA negative strains may have a lack of expression or inactivation
of their enterotoxin. TECRA-ELISA and PCR results did not correlate since
all PCR positive and negative strains were TECRA positive. This was expected
since the TECRA is reported to detect nontoxic proteins other than the
diarrheal enterotoxin. Studies are under way to detect the enterotoxin
and its gene in additional outbreak-related and environmental strains.
G. M. Matar, F. Anouti, J. Pruckler*, R. Weyant*, W. Bibb*
and B. Swaminathan*. (Supported in part by LNCSR.)
PCR-detection of an insertion (IS1) like element in clinical isolates of b -lactam resistant Enterobacter cloacae and Acinetobacter anitratum We
attempted to determine the relative occurrence of an insertion mutation
sequence (IS1-like element) by PCR in and outside the promoter
region of the bla-TEM gene in Enterobacter cloacae and Acinetobacter
anitratum nosocomial isolates resistant to b
-lactam antibiotics at the AUB Medical Center. The bla-TEM gene
was detected by PCR in all tested isolates. The relative occurrence of
the IS1-like element was higher in Enterobacter cloacae.
The presence of this element in the promoter region of the bla-TEM
gene was detected in only one isolate of Enterobacter cloacae which,
if coupled with amino acid mutations in the structural gene, may have the
potential to become resistant to third generation cephalosporins. Studies
are underway to detect the presence of this element in a larger number
of isolates. G. M. Matar, N. El-Ghossein and M. Uwaydah.
PCR-detection of mecA, mecI-mecR1 genes in clinical isolates of staphylococci in a Lebanese medical center We
PCR-amplified mecA, mecI, mec R1, and blaZ
specific sequences to determine their relative occurrence among staphylococcal
isolates recovered from clinical specimens at the AUB Medical Center. Isolates
were of various degrees of susceptibility to methicillin as determined
by the disk diffusion and agar dilution tests. All methicillin resistant
isolates were PCR positive for mecA gene. Methicillin-ras detected
by agar dilution correlated well with PCR detection of mecA gene.
PCR-amplification of mecA was particularly useful in detecting borderline-susceptible
isolates that may be considered potentially methicillin-resistant. The
mecI-mecR1 genes were variably distributed among
staphylococcal isolates. MecR1 was also detected in some
mecA positive borderline-susceptible staphylococci indicating the
potential for mecA gene to be expressed. The blaZ gene was
present in all tested mecA positive isolates implying that mecA
expression may be immediately inducible. These findings suggest that all
mecA positive staphylococci isolates should be regarded as intrinsically
methicillin-resistant with the potential of expressing resistance to methicillin.
G. M. Matar, D. Jaalouk, and M. Uwaydah. (Supported by AUB
Medical Practice Plan; Faculty of Medicine.)
PCR-identification of the etiology of chronic otitis in infected Lebanese children We
have developed a PCR-based assay for detecting the etiology of chronic
otitis in infected children from various hospitals in Lebanon. A total
of 38 MEE samples were aspirated during tympanostomy tube insertion from
30 patients having SOM. DNA was extracted from the MEE samples and PCR
was done on DNA extracts using universal primers. Twenty-nine of the 38
MEE samples (76.3%) gave the expected 370-bp band, thus indicating the
presence of bacterial DNA. Specific bacterial identification was done using
species-specific primers. Out of the 29 PCR-positive samples tested, 27
(93.1%) were positive for Haemophilus, 5 (17.2%) for Moraxella
catarrhalis, and 3 (10%) for Streptococcus pneumoniae. G.
M. Matar, N. Sidani, U. Hadi, and M. Fayad. (Supported
by LNCSR.)
Prevalence and resistance patterns of nosocomial bacterial pathogens This
was a descriptive, non-interventive surveillance study of species prevalence
and antimicrobial susceptibility pattern of aerobic Gram-negative bacterial
pathogens recovered from cultures of clinical specimens. Standard laboratory
procedures and API 20E and 20NE (API System) were employed for precise
species designation. Susceptibility to 12 antimicrobial agents was tested
by the Etest strips (AB Biodisk). The possible occurrence of ESBL mediated
resistance was checked using ceftazidime/clavulanate combination strips.
A total of 100 isolates were included in this study. The susceptibility/resistance
patterns of all the isolates were examined and compared and distinct profiles
were identified. M. Uwaydah. (Supported by Merck Human Health
Division, Whitehouse Station, N.J., USA.)
Efficacy of Fleroxaxin in the treatment of systemic bacterial infections The
study was designed as an open-label, noncomparative clinical trial for
the purpose of evaluating the efficacy, safety, and tolerability of fleroxacin
in the treatment of urinary tract infections and other acute systemic bacterial
infections in adult patients. Candidates were screened according to clearly-defined
inclusion and exclusion criteria. Informed consent was required and was
obtained from all 30 patients that were included in this study. Fleroxacin
proved to be highly effective in the control of acute urinary tract infections
when administered in a single dose (400mg) or in a once daily dose (200mg)
for 3 days. Relapses occurred only in patients with predisposing factors
and other underlying diseases. There was one patient with typhoid fever
whose response was evaluated as excellent. The selection of patients with
lower respiratory and soft tissue infections, that would benefit from treatment
with fleroxacin, warrant further investigations. The occurrence of mild
symptoms that may be attributed to the drug point to the need of more extensive
clinical trials for detecting potential adverse effects. M. Uwaydah.
(Supported by F.Hoffmann-La Roche, Basel, Switzerland.)
Abdelnoor, A.M., Bacterial endotoxin; from Ann Arbor via Philadelphia to Beirut. British Medical Journal (ME), 3, 7-11, 1996. Agello, G.*, Matar, G.M., Swaminathan, B.*, Bibb, W.* and Perkins, P.*, A rapid screening test for the etiologyc agent of Brazilian purpuric fever. Current Microbiology, 30, 345-349, 1995. Al-Shami, A. K., Itani, L. Y., Skaff, N. N., Haddad, E. K. and Abdelnoor, A. M., Effect of acetyl salicylic acid, tobramycin and vancomycin on some biological activities of endotoxin. Journal of Immunology Immunopharmacology, 15, 1-5, 1995. Kanaan, S., Saadeh, N., Haddad, J., Abdelnoor, A. M., Atweh, S., Jabbour, S. and Garabedian, B. Endotoxin-induced local inflammation and hyperalgesia in rats and mice: A new model for inflammatory pain. Pain, 66, 373-379, 1996. Kordick, D.*, Swaminathan, B.*, Greene, C.*, Wilson K.*, Whitney A.*, O’Connor, S.*, Hollis, D.*, Matar, G.M., Steigerwalt, A.*, Malcolm G.*, Hayes, P.*, Hatfield, T.*, Breitschwerdt, E.* and Brenner, D.*, Bartonella vinsonii subsp. berkhoffii subsp. nov., isolated from dogs; Bartonella vinsonii subsp. vinsonii, and emended description of Bartonella vinsonii. International Journal of Systematic Microbiology, 46, 704-709, 1996. Matar, G. M., Inter- and intraspecies identification of Bartonella species by PCR-RFLP analysis of a fragment of the ribosomal operon. Journal of Clinical Microbiology, 33, 3370, 1995. Matar, G. M., Hebert, G.* and Uwaydah, M., Characteristics of nosocomial versus outpatient isolates of coagulase-negative Staphylococci at a Medical Center in Beirut, Lebanon. Lebanese Scientific Bulletin, 8, 63-75, 1995. Matar, G. M., Khneisser, I. and Abdelnoor A., Rapid laboratory confirmation of human brucellosis by using a PCR analysis of a target sequence on the 31-kilodalton Brucella antigen DNA. Journal of Clinical Microbiology, 34, 477-478, 1996. Matar, G.M., Sharara, H., Abdelnour, G. and Abdelnoor, A., Genotyping of hepatitis C virus isolates from Lebanese hemodialysis patients by reverse transcription-PCR and restriction fragment length polymorphism analysis of 5’ noncoding region. Journal of Clinical Microbiology, 34, 2623-2624, 1996. Matar, G. M., Slieman, T. and Nabbut, N., Subtyping of Bacillus cereus by total cell protein profiles and arbitrary primer-polymerase chain reaction. European Journal of Epidemiology, 12, 309-1473, 1996. Matar, G.M., Traboulsi, R., Abdelnoor, A. and Osseiran, M., Serosurvey of HTLVI/II of a selected population In Lebanon. Revue Medicale Libanaise, 8, 23-24, 1996. Swaminathan, B.*, Matar, G.M., Reeves, M.*, Graves, L.*, Ajello, G.*, Bibb, W*, Helsel, L.*, Morales, M.*, Dronavalli, H.*, El-Swify, M.*, Dewitt, W.* and Hunter, S.*, Molecular subtyping of Neisseria meningitidis serogroup B: comparison of five methods. Journal of Clinical Microbiology, 34, 1468-1473, 1996. Uwaydah,
M., Jradeh, M. and Shihab, Z. Antimicrobial resistance of clinical isolates
of Streptococcus pneumoniae in Lebanon. Journal of Antimicrobial
Chemotherapy, 38, 283-286, 1996.
Abstracts, Presentations and Proceedings Abdelnoor, A.M., Serology, cell protein prifiles and PCR as tools in laboratory diagnosis and typing (abstract). Fifth Pharmacy Congress, Arab University, 1996. ———, Human leucocyte antigens complement dependent microcytotoxicity assay, DNA typing and SDS-PAGE of solubilized membranes (abstract). Eighth Arab Conference of Clinical Biology, First Jordanian Conference of Medical Laboratory Sciences, 84, 1997. Abdelnoor, A. M. and Chbaklo, H.Z. Endotoxin-hemoglobin interactions. Journal of Endotoxin Research, 3 (suppl. 1), 44, 1996. Abdelnoor, A. M., Khaled, G. and Ramadan, F. Some aspects of the immune response in tuberculosis. FASEB Journal, A1343 (1985), 1996. ———, Laboratory diagnosis of tuberculosis (abstract). Egyptian Conference on Chest Diseases and Tuberculosis, Cairo, Egypt, 1997. Abdelnoor, A.M., Mikhael, L. and Awargi, C., Effect of human hemoglobin on the activity of Bacterial LPS. Abstracts of American Society for Microbiology, 66, 1997. Abdelnoor, A.M., Nabulsy, G. and Khairallah, S., Effect of Nigella sativa extract on lymphocyte subsets and serum gamma interferon levels in mice. Ninth International Congress of Immunology, 872, Sam Francisco, USA, 1995. Abdelnoor, A.M. and Ramadan, F. Some aspects of the immuneresponse in tuberculosis. First Syrian Conference of Thoracic Medicine and Surgery, Damascus, Oct. 18, 1996. Bikhazi, A.B., Haddad, R.E., Nahle’, Z.A., El Kasti, M., and Abdelnoor, A.M., A novel rat perfusion method to assess endotoxin binding. II: Measurement of binding and residency time constants on capillary endothelium and myocyte plasma membranes. Journal of Endotoxin Research, 3 (suppl. 1), 57, 1996. Chamat, S., Walsh, E.E.*, Hanna, N.*, Anderson, D.* and Brams, P.*, Two neutralizing human monoclonal antibodies, specific for fusion protein of respiratory syncitial virus, isolated from hu-SCID mice. Official Publication of the Federation of American Societies for Experimental Biology, Abstract A1465, 1996. Garabedian, B., Kanaan, S., Haddad, H., Malik, J., Abdelnoor, A.M., Saadeh, N. and Jabbour, S., Hyperalgesia produced by endotoxin injections: A new model for localized inflammatory pain in rats and mice (abstract). Society for Neuroscience, 21, 643, 1995. Haddad, R.E., Bikhazi, A.B., Nahle’, Z.A., El Kasti, M. and Abdelnoor, A.M. A novel rat perfusion method to assess endotoxin binding. I: Description of perfusion model. Journal of Endotoxin Research, 3 (suppl. 1), 56, 1996. Matar, G. M., Anouti, F., Pruckler, J.*, Weyant, R.*, Bibb, W.* and Swaminathan, B.*, PCR Detection of Bacillus cereus diarrheal enterotoxin genes: comparison with commercial toxin kits. Ninety-Seventh General Meeting of the American Society for Microbiology, Abstract P-22, Miami Beach, USA, 1997. Matar, G.M., El-Ghossein, N. and Uwaydah, M., Relative occurrence of an insertion mutation sequence (IS1-like element) in nosocomial isolates resistant to beta-lactam antibiotics. Ninety-Seventh General Meeting of the American Society for Microbiology, Abstract A-10, Miami Beach, USA, 1997. Matar, G.M., Jaalouk, D., and Uwaydah, M., PCR-Detection of mecA, mecI-mecR1 genes in clinical isolates of staphylococci in a Lebanese Medical Center. Ninety-Seventh General Meeting of the American Society for Microbiology, Abstract A-16, Miami Beach, USA, 1997. Matar, G.M., Khneisser, I. and Abdelnoor, A., Rapid laboratory confirmation of human brucellosis by PCR analysis of a 31-kilodalton antigen DNA sequence. Ninety-Sixth General Meeting of the American Society for Microbiology, Abstract C-213, New Orleans, USA, 1996. Matar, G. M., Sharara, H., Abdelnour, G. and Abdelnoor, A., Genotyping of HCV in Lebanese hemodialysis patients by using a PCR-RFLP analysis of the 5’ non-coding region. Ninety-Sixth General Meeting of the American Society for Microbiology, Abstract C147, New Orleans, USA, 1996. Ramadan, F., Haadeh, F. and Abdelnoor, A.M., Identification of allergens in patients with allergic asthma in Lebanon. First Syrian Conference of Thoracic Medicine and Surgery, Damascus, Oct. 18, 1996. Ramadan,
F., Hamadeh, F. and Abdelnoor, A.M. Identification of allergens in patients
with allergic asthma in Lebanon. FASEB Journal, A 1480 (2766), 1996.
Abu Shakra, H., Antimicrobial heteroresistance in aerobic gram-negative bacilli (1996). Advisor: M. Uwaydah. El-Ghossein, N., PCR Detection of an insertion (IS1)-like element in clinical isolates of beta-lactam resistant E. cloacae and A. anitratum (1996). Advisor: G. M. Matar. Jaalouk, D., PCR Detection of MecA, MecI-MecR1 genes in clinical isolates of staphylococci (1996). Advisor: G. M.Matar. Khaled, G., Some aspects of the humoral immune response in tuberculosis (1996). Advisor: A.M. Abdelnoor. Khayyat, A., Evaluation of humoral immunity to viral pathogens among Filipine and Lebanese hospital staff (1996). Advisor: S. Chamat. Khneisser, I., Rapid laboratory confirmation of human brucellosis by using a polymerase chain reaction (PCR)-analysis of a target sequence on the 31kda brucella antigen DNA (1995). Advisor: G. M. Matar. Malak, R., HLA frequencies and corresponding lymphocyte protein profiles visualized on SDS-PAGE established through a study on a group selected from the Lebanese population (1996). Advisor: A.M. Abdelnoor. Racoubian, E., Antimicrobial effects of Nigella sativa seed extract; an in vitro study (1996). Advisor: N. Nabbut. Sharara, H., Utility of detection and typing of hepatitis C-virus (HCV) RNA in hemodialysis patients by PCR-RFLP analysis of the genomic 5’ noncoding region (1996). Advisor: G. M. Matar. Shbaklo, H., In vitro and in vivo evaluation of hemoglobin and endotoxin interaction (1996). Advisor: A.M. Abdelnoor.
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