S Yitzhaki

Publications (11)26.23 Total impact

• Article: A combined immunomagnetic separation and lateral flow method for a sensitive on-site detection of Bacillus anthracis spores--assessment in water and dairy products.

  M Fisher, Y Atiya-Nasagi, I Simon, M Gordin, A Mechaly, S Yitzhaki
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  ABSTRACT: Combination of immunomagnetic separation (IMS) and lateral flow device (LFD) assays for the development of a sensitive, rapid, on-site methodology that enables concentration and detection of Bacillus anthracis spores in complex samples. The data presents the development of an optimized, 30 min, IMS assay, with about 95% capture of B. anthracis spores from different dairy products (n = 38). No cross reactivity was detected with typical milk flora and some closely related Bacilli. To enable direct application of the IMS captured spores on the LFD, spores were eluted from the bead-spore complex utilizing 95% (v/v) formamide-10 mmol l(-1) EDTA for 30 s in a microwave oven. Detached spores were analysed on LFD enabling detection within 10 min. The combined IMS-LFD methodology (40 min) demonstrates a 60-fold improvement in sensitivity, relative to samples that were applied directly on the LFD without the IMS concentrating step. The IMS-LFD method is a powerful platform, combining rapidity, specificity and efficiency for concentrating and detecting B. anthracis from water and milk contaminated samples. The combination of IMS and LFD enhances the sensitivity and flexibility of B. anthracis spore detection from complex samples. This method can potentially be extended to other toxins and micro-organisms in a variety of matrices.
  Letters in Applied Microbiology 03/2009; 48(4):413-8. · 1.62 Impact Factor
• Article: An outbreak of leptospirosis among Israeli troops near the Jordan River.

  E Hadad, A Pirogovsky, C Bartal, J Gilad, A Barnea, S Yitzhaki, I Grotto, R D Balicer, E Schwartz
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  ABSTRACT: An outbreak of leptospirosis that involved 7 of a team of 27 Israeli troops occurred following a military exercise in northern Israel near the Jordan River. The organism implicated in the outbreak was Leptospira interrogans serovar Hardjo. The clinical course was uncomplicated and all patients fully recovered. There were no cases of asymptomatic infection. Military personnel should be recognized as having an occupational risk for contracting leptospirosis, especially when military activity takes place near natural water sources inhabited by cattle, taking into account the local epidemiology of this disease. Moreover, outbreaks among military personnel may serve as a sentinel for leptospiral illness in areas in which civilian exposure takes place, such as the Jordan River, which is an important site that involves immersion in the context of both pilgrimage and civilian recreational activities."Bathe and you will become clean. So he went down and immersed himself seven times in the Jordan, as Elisha had told him to do. And his flesh became clean once more like the flesh of a small child."II Kings 5:14.
  The American journal of tropical medicine and hygiene 02/2006; 74(1):127-31. · 2.59 Impact Factor
• Source

  Available from: Eran Zahavy

  Article: New approach for serological testing for leptospirosis by using detection of leptospira agglutination by flow cytometry light scatter analysis.

  S Yitzhaki, A Barnea, A Keysary, E Zahavy
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  ABSTRACT: Leptospirosis is considered an important reemerging infectious disease worldwide. The standard and most widespread method for the diagnosis of leptospirosis is the microscopic agglutination test (MAT). This test is laborious and time-consuming, and the interpretation of the results is subjective. In the present work we describe an application of flow cytometry (FCM) as a tool for the serological diagnosis of leptospirosis. The analysis is based on the sensitivity of FCM to the size and shape of the bacteria analyzed by measurement of light scatter parameters: forward scatter (FSC) and side scatter (SSC). The addition of positive serum to an infecting leptospiral serovar results in a shift of the light scatter parameter to a different location with higher FSC and SSC values, indicating the formation of leptospiral aggregates. By using immunofluorescent staining, we have shown that the large particles formed are the agglutinated leptospires. Quantification of the agglutination process has been achieved by calculating an agglutination factor (Af), based on changes in the light scatter parameters measured by FCM. Af enables us to determine the specificity of the serological reaction of the patient serum with each leptospiral serovar. In this work, 27 serum samples from 18 leptospirosis patients were tested by both the MAT and the FCM techniques, in which each serum sample was tested against 13 serovars. Twenty-six human serum samples derived from patients with a variety of other defined illnesses were used as negative controls and enabled us to define the Af threshold value as < 9.3 for negative patients, while any value higher than that would be a positive result for leptospirosis. Compared to MAT, the FCM technique was found to be more specific and sensitive, especially in identifying the serogroup in the acute phase of the disease. The whole process was found to be rapid and took less than 1.5 h. Moreover, FCM analysis is objective and can be automated for the handling of large numbers of samples.
  Journal of Clinical Microbiology 04/2004; 42(4):1680-5. · 4.15 Impact Factor
• Article: A Family of Correlation Coefficients Based on the Extended Gini Index

  Shlomo Yitzhaki, E. Schechtman
  The Journal of Economic Inequality 02/2003; 1(2):129-146. · 0.81 Impact Factor
• Article: Epidemiological and clinical features of leptospirosis in Israel.

  J Bishara, E Amitay, A Barnea, S Yitzhaki, S Pitlik
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  ABSTRACT: The epidemiology and clinical features of 46 cases of human leptospirosis diagnosed in Israel between 1986 and 1999 were analysed. The median patient age was 37.5 years (range, 16-85 years), and the male/female ratio was 43/3. The most common serogroup found was Leptospira icterohaemorrhagiae. The disease was associated with jaundice in 71% of cases, acute renal failure in 62%, rhabdomyolysis in 52%, pancytopenia in 28%, respiratory failure in 14% and disseminated intravascular coagulation in 5%. Leptospirosis occurs sporadically throughout the year, peaking during the summer months. A shift occurred from predominantly agriculture-related serogroups in the 1970s to urban-related serogroups during the study period reported, with Leptospira icterohaemorrhagiae being the dominant serogroup.
  European Journal of Clinical Microbiology 02/2002; 21(1):50-2. · 2.86 Impact Factor
• Article: On the proper bounds of the Gini correlation

  Shlomo Yitzhaki, E. Schechtman
  Economics Letters. 02/1999; 63(2):133-138.
• Article: Concentrating dilute protein solutions for gel electrophoresis.

  S Yitzhaki, J Sperling
  BioTechniques 06/1998; 24(5):762-4, 766. · 2.67 Impact Factor
• Source

  Available from: pnas.org

  Article: Phosphorylated Ser/Arg-rich proteins: limiting factors in the assembly of 200S large nuclear ribonucleoprotein particles.

  S Yitzhaki, E Miriami, R Sperling, J Sperling
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  ABSTRACT: We have previously shown that specific nuclear pre-mRNA transcripts and their splicing products, as well as the general population of nuclear poly(A)+ RNA, are packaged in large nuclear ribonucleoprotein (InRNP) particles that sediment at the 200S region in sucrose gradients. The InRNP particles contain all uridine-rich small nuclear ribonucleoprotein complexes required for pre-mRNA splicing, as well as protein splicing factors. In this paper we show that all of the phosphorylated, mAb 104 detectable, Ser/Arg-rich essential splicing factors (SR proteins) in the nucleoplasm are integral components of the InRNP particles, whereas only part of the essential splicing factor U2AF65 (U2 snRNP auxiliary factor) and the polypyrimidine tract binding protein (PTB) are associated with these particles. This finding suggests a limiting role for SR proteins in the assembly of the InRNP particles. We further show that the structural integrity of InRNP particles is sensitive to variations in the phosphorylation levels of the SR proteins.
  Proceedings of the National Academy of Sciences 09/1996; 93(17):8830-5. · 9.68 Impact Factor
• Article: [Use of psychotropic drugs in pregnancy and lactation].

  H Y Knobler, H Knobler, S Yitzhaki
  Harefuah 03/1994; 126(4):207-10.
• Article: Merging populations, stochastic dominance and Lorenz curves

  O. Stark, S. Yitzhaki
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  ABSTRACT: In typical comparisons of inequality the condition that the means of the distributions are equal is hardly met. In these cases, the widely used Lorenz curves non-intersection criterion is neither a necessary nor sufficient condition for stochastic dominance. It is suggested to replace the Lorenz curves non-intersection criterion with an absolute Lorenz curves non-intersection criterion. The implications of adopting this criterion are discussed in the context of fixed populations and changing populations.
  Journal of Population Economics 09/1988; 1(2):157-161. · 0.92 Impact Factor
• Source

  Available from: uni-muenchen.de

  Article: Labour migration as a response to relative deprivation.

  O Stark, S Yitzhaki
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  ABSTRACT: The relationship between labor migration and relative deprivation is examined. "We model migration from one reference group to another as a response to relative deprivation and satisfaction: We say that a strong incentive to migrate exists if relative deprivation decreases while satisfaction rises with migration and that a weak incentive exists if the individual increases or decreases his satisfaction and deprivation at the same time by migrating. We derive conditions under which different incentives, weak or strong, hold for different individuals.... Our analysis enables us to explain several perplexing migratory phenomena, identify income inequality as a distinct explanatory variable of migration and establish an incentive to migrate in situations where the utility-social welfare approach does not."
  Journal of Population Economics 07/1988; 1(1):57-70. · 0.92 Impact Factor