RESEARCH PROJECTS
Diagnosis of tuberculosis by rapid detection of Mycobacterium species in clinical specimens using polymerase chain reaction (PCR) Research
in progress. G. F. Araj and R. Talhouk. (Supported by URB.)
Detection of “mec A” gene in Staphylococcus aureus by polymerase chain reaction (PCR) Research
in progress. G.F. Araj and R. Talhouk. (Supported by URB.)
Molecular typing of methicillin-resistant Staphylococcus aureus isolates from community individuals, patients, and hospital staff in Lebanon Studies
on methicillin-resistant Staphylococcus aureus (MRSA) are scarce
in Lebanon. In this study, 32 MRSA isolates were typed according to their
antibiotic suseptibility patterns, whole-cell protein profiles, as determined
by SDS-PAGE, and their plasmid profiles. Protein analysis by SDS-PAGE of
whole-cell protein showed a total of 50-69 protein bands which were dominated
by 5 major band-clusters similar in all the isolates. Numerical analysis
of the protein patterns, and correlation studies revealed a degree of similarity
of the isolates, ranging between 74.1% and 100%. Plasmid profile analysis
(PPA) revealed 17 different groups among the 32 MRSA isolates. The number
of plasmids varied between 1 and 9. A 12 Kb and a 23 KB plasmid were most
common among the isolates with 81% and 31% frequency, respectively. In
addition, 12 isolates which had similar antibiotic susceptibility patterns
were further subdivided into 7 groups by PPA. This technique proved to
be superior to SDS-PAGE, and a valuable typing tool for MRSA. Restriction
endonuclease analysis (REAP) was attempted on 4 isolates belonging to 2
different groups according to PPA. This resulted in further differentiating
1 of the 2 groups into 2 subgroups. In conclusion the data shows that the
MRSA isolates in Lebanon are highly heterogeneous. Continued monitoring
and typing, using both conventional methods and PPA, of new MRSA isolates
is recommended. G. F. Araj, R.S. Talhouk and F. Hashwa (Supported
by AUB Medical Practice Plan.)
Karyotype analysis in chronic myelogenous leukemia (CML): a three-year experience at the American University of Beirut Medical Center We
report the results of karyotype analysis on cases referred to our laboratory
for CML over a period of three years. A total of 68 patients were referred
and a karyotype was successfully obtained in all cases except one. Thirty-one
percent of cases were found to have a normal karyotype, 58.5% were Philadelphia
(Ph1) positive while 10.5% of cases had chromosome abnormalities other
than Ph1. Among the Ph1 positive cases, 92% had the standard translocation
(9;22), 7.7% had a variant translocation and 12.8% had additional chromosome
abnormalities. Our results are compared to those generally reported in
the literature and the comparisons are discussed. This work is in press
in the Lebanese Medical Journal. W. Al-Assaad, G. Al-Oreibi and
L.
Zahed.
Development of new assays for the determination of anti-acetylcholine receptor antibodies Myasthenia
gravis is a disease associated with autoantibodies to post-synaptic acetylcholine
receptors (AChR). For the diagnosis and management of patients with myasthenia
gravis, anti-AChR antibodies have been quantitated by radioimmuno-precipitation
analysis using human muscle AChR labeled with I125. The disadvantages
of radioactive techniques are numerous. The cell line, TE671, is an alternative
source of AChR. In this project, we propose to develop two non-radioactive
methods for the determination of anti-AChR antibodies using the cell line
TE671: a) a rapid semi-quantitative flow cytometric assay, and b) a quantitative
enzyme linked immuno-sorbent assay (ELISA). R. Daher, S. Chamat
and C. Awaraji.
Apolipoprotein E polymorphism in a healthy Lebanese population Derangements
in lipoprotein structure and concentrations are prime factors in the development
of atherosclerosis. Apoliprotein-E mutations are most notorious in this
respect, leading to increased risk of premature atherosclerosis in the
coronary, peripherial aortic, and carotid vascular beds. The various phenotypes
can be detected by isoelectric focusing in gradient gels, but unequivalent
results can be obtained only by analysis at the gene level. Our novel research
project entails isotyping of normal as well as selected patient samples
of the Lebanese population in order to determine apo E genotypes, their
frequency as well as correlation in disease. Z. Habbal. (Supported
by URB.)
FLT3 Ligand as prognosticator and incubator of recovering bone marrow elements FLT3
Ligand, a cytokine, of unknown specific cell origin, works as a growth
factor in the stimulation of progenitor and stem cells. An isoform of this
ligand is present on stem cells which is increased concominantly with the
serum form in cases of severe aplastic anemia. Monitoring the serum level
and the mononuclear population receptor level can prove that FLT3 can be
used as a marker, first, in the evaluation of the effectiveness of chemotherapy;
second, the possibility of differentiation between malignant blasts and
regenerative normal stem cells; trying to understand the main cell producing
this growth factor. J. Haidar, R. Daher and A. Bazarbachi.
Fine needle aspiration of the mediastinum: A clinical, radiologic, cytologic and pathologic study of 42 cases Forty-two
FNAs of mediastinal masses over a 12-year period from AUB Medical Center
were reviewed. Ages ranged from 10 to 72, mean 41 years. There were 25
males and 17 females. The aspirated tumors were primary neoplasms (57%),
metastatic neoplasms (24%), benign conditions (12%) and inconclusive (7%).
FNA yielded adequate tissue for diagnosis in 83% of cases and were correctly
diagnosed in 86% of these. 5 cases were not correctly classified. The primary
neoplasms were 13 lymphoma (7 Hodgkin and 6 non-Hodgkin), 3 thymomas, 3
germ cell tumors, 1 angiosarcoma and 3 malignant neoplasms not otherwise
specified; the metastatic tumors were 9 carcinomas (6 from lung) and 1
sarcoma. Benign conditions included 2 granulomatous disease, 1 multinodular
goiter, 1 extramedullary hematopoiesis and 1 thymic cyst. We conclude that
FNA is an accurate, safe rapid and inexpensive technique for initial assesof
mediastinal masses. N. S. Shabb, M. Fahl, P. Haswani, G. Zaatari and
B.
Shabb.
Helicobacter pylori in Lebanon: histologic study of 500 gastric biopsies A
retrospective microscopic slide review of 500 gastric biopsies from the
pathology files at the AUB Medical Center. The aim of the study is to establish
baseline statistics concerning the incidence of H. pylori-related
gastritis in Lebanon. Preliminary data reveal that approximately 60% of
cases of histologically documented chronic gastritis are due to H. pylori
infection.
Pertinent demographic statistics pertaining to these cases are included
in the study. A. Tawil, A. Saad and F. Simaan.
Cytogenetic analysis of solid tumors Chromosome
analysis of tumoral tissue is helpful in the diagnosis and/or prognostication
of certain neoplasms. At the basic research level, it may lead to the identification
of specific chromosome rearrangements and sites of genes involved in tumorigenesis.
The most widely studied group of neoplasms have been the leukemias. Relatively
few solid tumors have been analyzed so far due to inherent technical difficulties.
Recently however, various cytogenetic techniques for studying such tumors
have been established and are increasingly being utilized worldwide. We
propose to use the appropriate technique(s) in order to establish solid
tumor karyotyping at AUB Medical Center, and to apply this routinely on
selected tumors. The tumors of interest in this study include malignant
round cell tumors of childhood, and certain adult soft tissue tumors (e.g.
lipogenic tumors), and thyroid neoplasms. A. Tawil and L. Zahed.
Acceptance of first-trimester prenatal diagnosis for the haemoglobinopathies in Lebanon We
have interviewed 83 couples at risk for a haemoglobin disorder, mostly
b
-thalassaemia, in an effort to evaluate their attitude towards first-trimester
prenatal diagnosis. Most of the families had received poor education and
were of low socio-economic status and more than half the couples were not
properly aware of their genetic risk. Fifty-nine per cent of the couples
were definitely in favor of prenatal diagnosis, 23% were uncertain at the
time of the interview and 18% were opposed to such testing, because of
their religious conviction against termination of a pregnancy. Another
important factor which seems to influence choice was the cost of the test.
Essential issues that arise from this study include the importance of a
control programme adapted to particular populations, proper information
and counselling, and the need for financial support in countries such as
Lebanon. The work is in press in Prenatal Diagnosis. L. Zahed
and
J. Bou-Dames.*
A familial complex chromosome rearrangement giving rise to balanced and unbalanced recombination products Over
35 familial CCRs have been described to date, but there are only four reports
of recombination derived from a parental CCR. This is the first familial
CCR transmitted over three generations, exhibiting transmission and recombination
through male and female carriers, with balanced and unbalanced recombination
products. The family was ascertained through a girl with a terminal deletion
of 8p. Her elder sister has partial trisomy for 8p. Their mother was found
to have a balanced complex 4-break chromosome rearrangement, involving
chromosomes 1, 8 and 9. Three-color FISH was performed using chromosome-specific
libraries to confirm this complex rearrangement, and telomeric probes were
used for chromosome 9q to refine the rearrangement. The CCR was also found
in one maternal uncle and the maternal grandfather in whom each chromosome
8 is involved in an independent translocation. L. Zahed, V. Der Kaloustian*
and J. Batanian*.
A cytogenetic register for Down syndrome in Lebanon The
total incidence of Down syndrome in a particular country depends on the
structure of its maternal population and on the health system and availability
of specialized medical services. Over the past five years, we have established
a cytogenetic register of Down syndrome in Lebanon in an effort to provide
data on the epidemiology of the disorder in our community. A total of 263
postnatal cases have been entered in the register, with information about
karyotype, age at referral, reason for referral, parental age, education
and occupation, pedigree and family history. The mean age of mothers of
Down syndrome children was found to be 32.19 years while 41.5% are of advanced
maternal age (35 years and above). The Down syndrome child is the third
or higher in the birth order in 52.36% of cases, and only 47.3% of Down
syndrome children were diagnosed at less than one month of age. While cytogenetic
findings are in accordance with those reported in larger registers, the
sex ratio of 1.66 is significantly more elevated (P < 0.01). Prenatal
diagnosis is currently available in Lebanon, however, its uptake is still
very limited and therefore emphasis in a potential prevention programme
might need to be placed on education, information and family planning.
L.
Zahed and A. Megarbane*.
The molecular basis of b -thalassaemia intermedia in Lebanon After
analysing the molecular basis of b-thalassaemia
in Lebanon, we are currently studying families with b
-thalassaemia intermedia, in an attempt to identify the different mechanisms
contributing to the milder form of the disorder, which can vary with different
population groups. Thalassaemia intermedia can be due to mild b
-thalassaemia mutations, co-inheritance of a
-thalassaemia or HPFH (Hereditary Persistence of Fetal Haemoglobin). We
have started collecting DNA from the families concerned, after taking their
haematological and clinical data. The samples are currently screened for
b
-thalassaemia mutations using an allele-specific PCR technique (ARMS-PCR).
The a
genotypes will be done by Southern blot analysis in collaboration with
Dr John Old at the Institute of Molecular Medicine in Oxford, England.
For HPFH, screening will be done by analysis of a common polymorphism in
the g-globin gene (XmnI-gG) involving PCR and restriction enzyme digestion.
L.
Zahed, A. Taher, R. Al-Dana and J. Old.* (Supported by LNCSR.)
The spectrum of b -thalassaemia mutations in Lebanon We
screened 110 DNA samples from carriers of b
-thalassaemia, using the ARMS-PCR technique with primers for common Mediterranean
mutations. Unidentified samples were subjected to heteroduplex analysis
with Universal Heteroduplex Generators (UHGs) covering the b-globin gene,
followed by DNA sequencing. In total, 16 different mutations were detected,
the most frequent being IVSI-110 (40%), followed by other common Mediterranean
mutations (IVSI-1, IVSII-1, IVSI-6). Other mutations detected were of Lebanese,
Turkish, Iranian, Kurdish, Bulgarian and Asian-Indian origin. The most
heterogeneous religious group seems to be the Sunni Muslims, with 13 mutations,
while only 2 mutations were detected among the Christian Maronites. Results
from this study are compared with those from other Mediterranean and neighbouring
countries. This work has been accepted for publication in Human Heredity.
L.
Zahed, R. Talhouk, M. Saleh, R. Abou-Jaoudeh, C. Fisher* and
J.
Old.* (Supported in part by LNCSR. Part of the work was completed through
a fellowship by the Thirld World Academy of Science.)
Abdo,
R.A., Araj, G.F. and Talhouk, R.S., Methicillin resistant Staphylococcus
aureus (MRSA): disease spectrum, biologic characteristics, resistant
mechanisms, and typing methods. Lebanese Medical Journal, 44
(1), 21-30, 1996.
Araj,
G.F., Abdul-Baki, N.Y.*, Hamze, M.M*., Alami, S.Y., Nassif, R.E. and Naboulsi,
M.S.*, Prevalence and etiology of intestinal parasites in Lebanon. Lebanese
Medical Journal, 44 (3), 129-133, 1996.
Araj, G.F. and Atamian, R.B., Reliability of rapid kits for Staphylococcus aureus identification. Laboratory Medicine, 28 (2), 126-130, 1997. Araj, G.F. and Awar, G.N., The value of ELISA vs. negative Coombs findings in the serodiagnosis of human brucellosis. Serodiagnosis and Immunotherapy in Infectious Disease, 8, 169-172, 1997. Araj, G.F. and Azzam, R.A*., Seroprevalence of brucella antibodies among persons in high risk ocupation inLebanon. Epidemiology and Infection, 117, 281-288, 1996. Araj, G.F., Kfoury-Baz, E., Barada, K.A., Nassif, R.E. and Alami, S.Y., Hepatitis C Virus: Prevalence in Lebanese blood donors and brief overview of the disease. Lebanese Medical Journal, 43 (1), 11-16, 1995. Baddoura, F.K.*, Unger, E.R.*, Mufarrij, A., Nassar, V.H.* and Zaki, S.R*., Latent Epstein-Barr Virus (EBV) infection is an unlikely event in the pathogenesis of immunoproliferative small intestinal disease. Cancer, 74, 1699-1705, 1995. Daher, R. T., Trace metals (lead and cadmium exposure screening). Analytical Chemistry, 67, 405R-410R, 1995. Habbal, Z. M. and Muwakkit, S., Apparent positive interference from an etoposide metabolite, but not etoposide, in measurement of urinary VMA. Clinical Chemistry, 42, 415-416, 1997. Haidar, J. H., Neiman, R.S.*, Orazi, A.*, Albitar, M.*, McCarthy, L.J.* and Heerman, N.*, Mdm-2 oncoprotein expression in mantle cell lymphoma with blastoid transformation. Modern Pathology, 9 (4), 355-359, 1996. Habbal, Z.M. and Touma, E.H.*, Positive interference from homocystinuria urine in a spot test for molybdenum cofactor deficiency. Clinical Chemistry, 41, 1056-1057, 1995. Homayoun, P.*, Daher, R., Van Lente, F.*, Faiman, C.*, and Gupta, M.K.*, Immunoradiometric assay measurements of insulin-like growth factor-I (IGF-I): comparison with radioimmunoassays using native or des(1-3) IGF-I as radioligands. Journal of Clinical Laboratory Analysis, 10, 446-450, 1996. Nasr, F.W., Mufarrij, A.A. and Ashkar, K.*, Mondor’s disease. A forgotten cause of anterior chest pain. Lebanese Medical Journal, 44, 41-43, 1996. Richard, G.K.*, Freeborn, W.A.* and Zaatari, G.S., Hemangiopericytoma of the renal capsule. Journal of Urologic Pathology, 4, 85-98, 1996. Saadah, M.A.*, Araj, G.F., Diab, S.M.* and Nazaal, M.*, Cryptococcal meningitis and confusional psychosis: A case report and literature review. Tropical and Geographical Medicine, 47 (5), 224-226, 1995. Shabb, N.S., Phyllodes tumor: Fine needle aspiration cytology of eight cases. Acta Cytologica, 41, 321-326, 1997. Vasef,
M.*, Zaatari, G.S., Chan, W.C.*, Sun, N.C.J.*, Weiss, L.M.* and Brynes,
R.K.*, Dendritic cell tumors associated with low-grade B-cell malignancies:
report of three cases. American Journal of Clinical Pathology, 104,
696-701, 1995.
ABSTRACTS, CONFERENCES AND PROCEEDINGS Awaraji,
C. and Daher, R., Evidence of dyserythropoiesis in a group of renal dialysis
patients using a rapid flow cytometric method. Thirty-Second Middle
East Medical Assembly, Beirut, Lebanon, 1997.
Daher,
R., and Van Lente, F.*, Relationship of increased homocysteine with copper,
iron, and zinc concentrations in serum. Irish Journal of Medical Sciences,
164 [Suppl 15], 21, 1995.
Habbal, Z.M. and Sakr, A., Modified amino acid analysis by HPLC: Use of a guard column immediately after the quaternary pump greatly improves resolution and conserves retention times (poster presentation). Advanced Technology, Biotechnology ’95 Conference, Milan, Italy, Nov. 28-Dec. l, 1995. Gupta, M.K. *, Homayoun, P.*, Daher, R., and Van Lente, F.*, Direct measurement of free IGF-I by IRMA: comparison with RIA after HPLC separation. Clinical Chemistry, 41, S40, 1995. Hamze, M.* and Araj, G.F., Drug resistance among Mycobacterium tuberculosis in Lebanon. Seventeenth Annual Meeting of the European Society for Mycobacteriology, Abstract 002, 49, Institute Pasteur, Paris, France, June 5-8, 1996. Licata, A.*, Van Lente, F.* and Daher, R., Comparison of serum interleukin-6 (IL-6) with bone markers in treated and untreated osteoporosis. Journal of Bone and Mineral Research, 10[Suppl], P204, 1995. Saad, A.J., Marple, T.G.*, Laucirica, R.* and Zaatari, G.S., Image analysis for ploidy and Ki-67 on previously stained fine needle aspirates. Comparison with flow cytometry on paraffin-embedded tissue. American Society of Cytology, Forty-Fourth Annual Scientific Meeting, Denver, USA, 1996. Talhouk, R.S.*, El-Dana, R.A.*, Barbour, E.* and Araj, G.F. Prevalence and characterization of Campylobacter in Lebanon. Ninety-Seventh Anuual Meeting of the American Society for Microbiology, Abstract C-273, Miami Beach, USA, 1997. Zahed, L. and Batanian, J*., A rare familial complex translocation t(1;8)(p31;q21.1)t(8;9)(p23.1;q34). Proceedings of First European Cytogenetics Conference, Athens, Greece, June 1997. Zahed, L., Bou-Dames, J.* and Torbey, P-H.*, Acceptance of prenatal diagnosis for the hemoglobinopathies in Lebanon. American Society of Human Genetics Annual Meeting. American Journal of Human Genetics, 57, A299, October 1995. Zahed, L., Al-Dana, R., Koussa, S.* and Taher, A., The molecular basis of b -thalassaemia intermedia in Lebanon. Proceedings of Sixth International Conference on Thalassaemia and the Haemoglobinopathies, Malta, April 1997. Zahed, L., Saleh, M., Abou-Jaoudeh, R., Talhouk, R. and Old, J*., b -thalassaemia mutations in the Lebanese population. Ninth International Congress of Human Genetics. Brazilian Journal of Genetics, 19, 103, August 1996. Zahed, L., Talhouk, R., Saleh, M., Abou-Jaoudeh, R., Fisher, C.* and Old, J.*, The spectrum of b -thalassaemia mutations in Lebanon. American Society of Human Genetics Annual Meeting. American Journal of Human Genetics, 59, A194, October 1996.
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