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עמוד בית
Fri, 05.12.25

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April 2009
O. Sadan, N. Shemesh, Y. Cohen, E. Melamed and D. Offen

Background: Stem cell-based therapy is a promising approach for the treatment of neurodegenerative disease. In our laboratory, a novel protocol has been developed to induce bone marrow-derived mesenchymal stem cells into neurotrophic factor-secreting cells. These cells produce and secrete factors such as BDNF (brain-derived neurotrophic factor) and GDNF (glial-derived neurotrophic factor).

Objectives: To evaluate the migratory capacity and efficacy of NTF-SC[1] in animal models of Parkinson's disease and Huntington's disease.

Methods: MSCs[2] underwent two-phase medium-based induction. An efficacy study was conducted on the 6-hydroxydopamine-induced lesion, a rat model for Parkinson's disease. Cells were transplanted on the day of 6-OHDA[3] administration, and amphetamine-induced rotations were measured as a primary behavioral index. In a second experiment, migratory behavior was examined by transplanting cells a distance from a quinolinic acid-induced striatal lesion, a rat model for Huntington's disease. Migration, in vivo, was monitored using longitudinal magnetic resonance imaging scans followed by histology.

Results: NTF-SCs attenuated amphetamine-induced rotations by 45%. HPLC analysis demonstrated a marked decrease in dopamine depletion, post-cellular treatment. Moreover, histological assessments revealed that the engrafted cells migrated and acted to regenerate the damaged striatal dopaminergic nerve terminal network. In a preliminary work on an animal model for Huntington's disease, we demonstrated by high resolution MR images and correlating histology that induced cells migrated along the internal capsule towards the QA[4]-induced lesion.

Conclusions: The induced MSCs are a potential therapy for neurodegenerative diseases, due both to their NTF secretion and their ability to migrate towards the diseased tissue.






[1] NTF-SC = neurotrophic factor-secreting cells



[2] MSCs = mesenchymal stem cells



[3] 6-OHDA = 6-hydroxydopamine



[4] QA = quinolinic acid



 
August 2007
E. Cohen-Hillel, I. Yron, T. Meshel and A. Ben-Baruch

Background: Interleukin-8 is a prototypical inflammatory chemokine that induces leukocyte migration to inflammatory sites. Leukocyte recruitment in response to gradients of this chemokine is attenuated at advanced stages of inflammation to prevent damage to surrounding healthy tissues. Our published studies suggest that over-phosphorylation of focal adhesion kinase in migration-desensitizing conditions is involved in cessation of cell motility. This over-phosphorylation of FAK[1] was induced by IL-8[2] only when the receptor transmitting the chemokine signals was CXCR2, and not CXCR1, indicating that the two IL-8 receptors diverge in their signaling properties.

Objectives: To analyze the regulation of FAK in CXCR2-expressing hematopoietic cells under conditions of migratory desensitization, focusing on the roles played by adhesion-related components in this process.

Methods: Under conditions of migratory desensitization, we determined IL-8-induced cell spreading and FAK localization following disruption of actin filaments, and evaluated the role of integrins in FAK phosphorylation.

Results: The disturbance of intact activity of actin filaments resulted in inhibition of cell spreading and modification of FAK intracellular localization upon IL-8 stimulation. Also, adhesion-dependent pre-stimulation of integrins was required for IL-8-induced FAK phosphorylation.
Conclusions: Intact actin filaments and integrins are required for optimal IL-8-induced FAK phosphorylation in conditions of migratory desensitization. These observations suggest that lack of adequate activity/regulation of adhesion-related components may give rise to FAK activities that are not appropriately controlled, possibly leading to pathological conditions that are associated with perturbed leukocyte migration phenotypes







[1] FAK = focal adhesion kinase



[2] IL = interleukin


September 2006
D. Chemtob, B. Damelin, N Bessudu-Manor, R. Hassman, Y. Amikam, J.M. Zenilman and D. Tamir

Background: Israel, as a country of immigration, has a heterogeneous distribution of risk for human immunodeficiency virus. Therefore, general population-based surveys of sexual behaviors among young adults may be useful for guiding prevention policy. To the best of our knowledge, the present survey is the first one among Israeli adults ever published.

Objectives: To survey knowledge, attitudes and practices regarding sexually transmitted infections in Israeli adults in order to target the future AIDS public campaigns for the general population.

Methods: A national sample of 800 individuals, aged 18–45, was interviewed telephonically in September 2000.

Results: The average number of sexual partners reported in the previous 3 months was 1.3. Accurate knowledge on HIV[1] transmission modes was expressed by 99% of respondents for unprotected sexual intercourse, 97% for re-use of needles and syringes, and 85% for mother-to-child infection. However, incorrect notions on transmission were also prevalent (34% for insect bites, 29% for kissing and 21% for public toilets). Prevention of STIs[2] and prevention of pregnancy were the most common reasons for using condoms (72–73%); HIV prevention was the motivation for 39%. Fifty percent of single individuals without steady partners always/usually used condoms. It was decided that women need empowerment to negotiate condom use.

Conclusions: Gaps were found between knowledge (at high level), attitudes (perceiving greater risk for others than themselves) and behavioral practices (combining low level of partner exchange with widespread disregard for safe sex). Promptly implemented, these findings will serve as a baseline for further surveys.






[1] HIV = human immunodeficiency virus



[2] STI = sexually transmitted infection


January 2006
D. Chemtob, D. Weiler-Ravell, A. Leventhal, H. Bibi

Background: During the last decade, Israel, a country with low tuberculosis rates, absorbed some 900,000 new immigrants from TB[1]-endemic countries.

Objectives: To analyze the specific impact of our screening procedures on active TB among children in Israel.


Methods: We conducted a retrospective analysis of epidemiologic and clinical data of all children (aged 0–17) with TB notified to the Ministry of Health between 1990 and 1999.


Results: There were 479 children with TB (male/female ratio 1.36). Most cases (81.8%) were foreign born, predominantly (88.2%) immigrants from Ethiopia and, therefore, huge differences existed in TB incidence rates according to countries of origin. Some 80% were diagnosed within 3 years of arrival, mainly due to active case-finding. Pulmonary TB, with infiltrates on chest X-ray, was found in 49.5%. Extra-pulmonary TB sites were: intra-thoracic lymphadenitis (31.1%), extra-thoracic lymphadenitis (12.5%), bones (3.6%), pleura (1.3%), meninges (1%), and others (1%). Seventy percent had a tuberculin skin test reaction ≥10 mm in size. Two (non-immigrant) children died of TB meningitis.


Conclusions: Most of the pediatric TB cases occurred in recent immigrants and were diagnosed within 3 years of immigration. These data support our policy of active case-finding among new immigrants from Ethiopia and extensive contact evaluation for all TB cases.






[1] TB = tuberculosis


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