• IMA sites
  • IMAJ services
  • IMA journals
  • Follow us
  • Alternate Text Alternate Text
עמוד בית
Fri, 19.07.24

Search results


August 2006
I. Goldberg Cohen, G. Beck, A. Ziskind and J. Itskovitz-Eldor
 Embryonic stem cells, derived from the inner cell mass of embryos in the blastocyst stage, are cells capable of perpetual self-renewal and long-term propagation and hold the potential to differentiate to progeny of the three embryonic germ layers. Since their derivation approximately two decades ago, exploration of mouse ES cells made major advances in ES cell differentiation research and in the successful development and propagation of various cell types. The subsequent derivation of ES cells from human embryos allows detailed study of early developmental events practically unreachable in early human embryos, and the potential derivation of a variety of adult cell types differentiated from the ES cells holds immense therapeutic promise. Recently, the study of ES cell-derived teratomas identified the partial presence of human ES cell-derived premature vessels within the teratoma, and a preliminary protocol for the in vitro derivation of a vascular progenitor was developed based on the study with the mouse ES cells. Furthermore, genetic profiling identified a pattern of expression of various endothelial and vascular smooth muscle cell genes that provide additional Information on the degree of vascular development that ES cells undergo. Finally, the clinical application of ES cells in transplantation medicine is closer than ever following the affirmation that human ES cell-derived endothelial progenitors conferred increased neovascularization in transplanted engineered skeletal muscle. This review summarizes these recent advances in vascular development from human ES cells and their potential clinical applications.

July 2006
I. Topilski, O. Rogowski, A. Glick, S. Viskin, M. Eldar and B. Belhassen
 Background: Atrioventricular nodal reentry tachycardia is the most frequent cause of regular, paroxysmal supraventricular tachycardia. Radiofrequency ablation of the slow pathway has been recommended as first-line therapy for curing AVNRT[1].

Objectives: To report a 14 year experience of RFA[2] of the slow pathway in patients with AVNRT treated in our laboratory.

Methods: A total of 901 consecutive patients (aged 9–92, mean 50.8 ± 18.2 years) underwent RFA of the slow pathway. All patients had sustained AVNRT induced with or without intravenous administration of isoproterenol. A standard electrophysiologic method with three diagnostic and one ablation catheter was used in 317 patients (35.2%); in the remaining 584 patients (64.8%), only two electrode catheters (one diagnostic, one ablation) were used ("two-catheter approach").

Results: Catheter ablation of the slow pathway abolished AVNRT induction in 877 patients (97.3%). In 14 patients (1.6%) the procedure was discontinued while in 10 (1.1%) the procedure failed. In 864 patients (95.9%) there were no complications. Transient or permanent AV block occurred during the procedure in 31 patients (3.4%), of whom 8 (0.9%) eventually required pacemaker insertion (n=7) or upgrade of a previously implanted VVI pacemaker (n=1) during the month following the procedure. The number of catheters used did not significantly affect the rate of results or complications of the ablation procedure. The success and complication rates remained stable over the years, although a significant trend for increased age and associated heart disease was observed during the study period.

Conclusions: The results of this single-center large study, which included patients with a wide age range, showed results similar to those of previous studies. The use of a "two-catheter approach" (one diagnostic and one ablation) was as effective and safe as a multi-catheter approach.


 





[1] AVNRT = atrioventricular nodal reentry tachycardia

[2] RFA = radiofrequency ablation


D. Starobin, M.R. Kramer, A. Yarmolovsky, D. Bendayan, I. Rosenberg, J. Sulkes and G. Fink
 Background: Different exercise tests are used to evaluate the functional capacity in chronic obstructive pulmonary disease. The cardiopulmonary exercise test is considered the gold standard, but the 6 minute walk and the 15 step exercise oximetry tests are considerably less expensive.

Objectives: To determine whether reliable data could be obtained at lower cost.

Methods: The study sample consisted of 50 patients with mild to severe stable COPD]1[. All underwent pulmonary function test and the cardiopulmonary exercise test, 6 minute walk and 15 step exercise oximetry test as part of their regular follow-up visit. Functional capacity was graded according to each test separately and the functional capacities obtained were correlated.

Results: The results showed that most of the patients had severe COPD according to pulmonary function tests (mean forced expiratory volume in the first second 46.3 ± 19.9% of predicted value). There was a good correlation between the cardiopulmonary exercise test and the 6 minute walk functional capacity classes (r = 0.44, P = 0.0013). We did not find such correlation between the 15 step exercise oximetry test and the cardiopulmonary exercise test (r = 0.07, P = 0.64).

Conclusions: The study shows that the 6 minute walk is a reliable and accurate test in the evaluation of functional capacity in COPD patients.


 





[1] COPD = chronic obstructive pulmonary disease


Y. Turgeman, P. Levahar, I. Lavi, A. Shneor, R. Colodner, Z. Samra, L. Bloch and T. Rosenfeld
 Background: Adult calcific aortic stenosis is a well-known clinical entity but its pathophysiology and cellular mechanism have yet to be defined.

Objectives: To determine whether there is an association between the presence and severity of adult calcific aortic stenosis and Chlamydia pneumoniae seropositivity

Methods: Forty adult patients (23 women, 17 men) were divided into three groups according to echocardiographic aortic valve area: Group A – 7 symptomatic subjects (age 67 ± 7 years) with normal aortic valve and normal coronary angiogram, Group B – 16 patients (age 73 ± 6) with moderate ACAS[1] (AVA[2]> 0.8 £ 1.5 cm2), and Group C – 17 patients (age 76 ± 7) with severe ACAS (AVA £ 0.8 cm2). We tested for immunoglobulins M, G and A as retrospective evidence of C. pneumoniae infection using the micro-immunofluorescence method. Past C. pneumoniae infection was defined by IgG titer > 16 £ 512.

Results: No patients in Group A showed positive Ig[3] for C. pneumoniae. IgM was not detected in any of the patients with ACAS (groups B and C) while 2 of 17 patients (12%) in group C showed IgA for the pathogen. High titers of IgG were found in 14 of 33 (42%) of the patients with moderate or severe ACAS: 5 of 16 (31%) in group B and 9 of 17 (53%) in group C (P = 0.2). Both groups had the same prevalence of coronary artery disease (66%). AVA was lower in IgG-seropositive patients than in the seronegative group (0.88 ± 0.3 cm2 vs. 1.22 ± 0.4 cm2, respectively, P = 0.02).

Conclusions: Past C. pneumoniae infection may be associated with a higher prevalence and greater severity of ACAS.


 





[1] ACAS = adult calcific aortic stenosis

[2] AVA = aortic valve area

[3] Ig = immunoglobulin


M. Katz Leurer, E. Be'eri and D. Zilbershtein
 Background: There is a growing demand for respiratory rehabilitation services for children dependent on tracheostomy and/or chronic mechanical ventilation. Discharging these patients home following their rehabilitation can be an arduous process.

Objectives: To define the length of time required to rehabilitate and discharge these patients, and to identify predictors of a prolonged or failed discharge process.

Methods: We conducted a retrospective chart review of patients admitted to the Respiratory Rehabilitation Unit at Alyn Hospital, Jerusalem, over a 4 year period.

Results: Of the 48 patients identified, 31 (64.7%) were eventually discharged, 13 (27.1%) remained hospitalized long-term, and 4 (8.3%) died during their hospitalization. The median length of hospitalization was 10 months: 6 months for purposes of rehabilitation therapy, and 4 months thereafter to resolve the logistics of discharge. Specific family characteristics – an unemployed father (odds ratio = 4.6, P = 0.02) and an additional family member with a disability (OR[1] = 5.8, P = 0.03) – as well as ongoing mechanical ventilation at the time of discharge (OR = 5.5, P < 0.01) were found to positively correlate with a prolonged or failed discharge process.

Conclusions:  Hospitalization in a pediatric respiratory rehabilitation unit may be prolonged for both medical and non-medical reasons, with the process of discharge home being particularly difficult in certain subsets of patients. A proactive discharge policy by hospitals, improved community support services, and legislation defining the rights of home-ventilated children may facilitate more efficient discharge home of these patients.


 





[1] OR = odds ratio


T. Hershcovici, T. Chajek-Shaul, T. Hasin, S. Aamar, N. Hiller, D. Prus and H. Peleg
June 2006
R. Rosenberg, S. Vinker, J. Yaphe and S. Nakar
 Background: Maintaining a death register and holding staff discussions about patients who died can aid the physician in audit and research, which will lead to improved care of the terminally ill and the bereaved and to the development of prevention strategies. These issues are important for students and residents as well.

Objectives: To review the value of mortality-case discussions in primary care clinics, particularly teaching clinics.

Methods: The clinic death register, instituted in 1998, includes age, gender, cause of death, place of death, relevant illnesses, and support provided to the patient before the death. In the half-yearly sessions, the data are reviewed, and individual cases that had an emotional impact on the staff, or information that can bring about changes in future care are discussed by the clinic staff and trainees.

Results: In our clinic 233 deaths occurred during a 6 year period (1998–2003). The crude all-cause mortality rate was 7.1/1000. The median age was 80 years old. Neoplastic causes were slightly more frequent than cardiovascular causes of death. Only 15% died at home; 20% lived alone and 70% lived with a spouse or family members before the death. Topics discussed in the mortality review meetings include identifying pre-suicidal patients, when to hospitalize the sick elderly, dealing with the anger of bereaved families, and ensuring proper home care for terminal patients.

Conclusions: We recommend keeping a death register and conducting mortality review sessions in order to improve the quality of care, emotional support of the staff, and training students and residents about the complex issues surrounding the death of patients.

D. Prais, Y. Raviv, D. Shitrit, A. Yellin, G. Sahar, D. Bendayan, Y. Yahav, O. Efrati, N. Reichart, H. Blau, I. Bakal, G. Buchman, M. Saute, B. Vidne and M.R. Kramer
 Background: Lung transplantation is a well-established therapeutic option for end-stage lung disease in cystic fibrosis. Although it confers a clear survival advantage, outcome differs among centers according to local experience, patient selection, transplantation procedure, and postoperative care.

Objectives: To evaluate the national Israeli experience with lung transplantation in patients with CF[1].

Methods: We reviewed the medical charts of all CF patients who underwent lung transplantation between January 1996 and June 2005 at the two Israeli centers that performed this procedure.

Results: Eighteen transplantations were performed in 17 patients. Mean patient age at transplantation was 25.3 ± 9.1 years, and mean duration of follow-up in survivors (n=14) was 37.2 months (range 1–113 months). The actuarial survival rate was 88% at 1 year and 74% at 5 years. Pulmonary function, expressed as percent of predicted normal forced expiratory volume in 1 sec, improved from 22.4 ± 8.1% to 76 ± 16.8% at one year after transplantation. Bronchiolitis obliterans syndrome was diagnosed in 5 patients (29%), of whom 2 died and 2 are currently candidates for retransplantation. Median time to onset of BOS[2] was 34.2 months (range 17–64 months).

Conclusion: In Israel, the early and intermediate-term results of lung transplantation for cystic fibrosis are encouraging. BOS remains a major complication that threatens long-term outcome.


 





[1] CF = cystic fibrosis

[2] BOS = bronchiolitis obliterans syndrome


I. Meivar-Levy and S. Ferber
Recent advances in pancreatic islet transplantation emphasize the potential of this approach for the long-term control of blood glucose levels as treatment of diabetes. To overcome the organ shortage for cell replacement therapy, efforts are being invested in generating new and abundant sources of insulin-producing cells from embryonic or adult stem cells. We review recent evidence documenting the surprising capacity of the mature liver to serve as a potential source of tissue for generating functional endocrine pancreas. The process of liver-to-pancreas developmental redirection is induced by ectopic expression of pancreatic transcription and differentiation factors. This approach may allow the diabetic patient to be the donor of his or her own therapeutic tissue, thus alleviating both the need for allotransplantations and the subsequent immune suppression.

 

May 2006
O. Hochwald, E. Bamberger and I. Srugo

The Israel Ministry of Health’s epidemiology department reported a record number of 1564 new pertussis cases in 2004. This brings the incidence rate to 23 per 100,000 population, indicating a marked increase in the prevalence of pertussis, from 1–3/100,000 in 1998, 9 in 2001, to 14 in 2003. The rate of atypical pertussis presentations in vaccinated patients, the decline in pertussis immunity post-vaccination, and the decreased awareness of potential infections in the adult population make the diagnosis of pertussis difficult and contribute to the rising incidence. In this article we review the current literature in order to increase awareness of the occurrence of pertussis in children as well as adults, discuss the laboratory diagnostic methods being used, and report the currently recommended means of treating the disease.

L.M. Shulman, Y. Manor, D. Sofer, T. Swartz and E. Mendelson

Background: Poliovirus rapidly evolves by nucleic acid substitutions and genetic recombination with other polioviruses and non-polio enteroviruses. Evolving oral poliovirus (Sabin strains) can rapidly revert to neurovirulence and undergo antigenic alterations.

Objectives: To evaluate the threat of vaccine-derived poliovirus (1–15% divergence from the respective Sabin strain) for a poliomyelitis-free population in a country with a long-standing routine vaccination program.

Methods: We characterized genetic and antigenic changes in OPV[1] strains isolated from sewage in Israel and evaluated intestinal immunity by measuring fecal excretion after OPV challenge of vaccinated children.

Results: Characterization of poliovirus from sewage revealed eight type 2 and three type 3 vaccine polioviruses that had replicated and started to evolve (vaccine that replicated and diverged by 0.5 to ≤ 1.0%) and nine highly diverged type 2 vaccine-derived polioviruses (1–15% divergence from the respective Sabin strain) with 8–14% divergence between the years 1998 and 2005. Six of the eleven VRPV[2] uniquely recombined with OPV and/or NPEV[3]. The nine VDPV[4] were epidemically related, genotypically neurovirulent, and had 10–15 amino acid substitutions in antigenic sites altering their antigenicity, but shared a single recombination. Type 2 OPV was excreted by 23% and 17% of infants challenged with OPV 3 months after partial immunization (two doses each of OPV and enhanced inactivated poliovirus) or full immunization (three doses of each) respectively, despite high humoral antibody titers.

Conclusions: Our findings, which show that OPV is excreted for a significant period by children with high humoral immunity, emphasize the long-term potential threat from VDPV in highly vaccinated populations. An adequate immunization program, combined with environmental surveillance, is necessary to prevent poliomyelitis and community transmission of poliovirus. 


 




[1] OPV = oral poliovirus

[2] VRPV = vaccine poliovirus that has replicated and started to evolve but is < 1 % but at least 0.5% diverged from the respective Sabin strain

[3] NPEV = non-polio enterovirus

[4] VDPV = vaccine-derived poliovirus 1–15% divergence from the respective Sabin strain


H. Joffe, E. Bamberger, S. Nurkin, E. Kedem, Z. Kra-Oz, S. Pollack and I. Srugo

Background: The co-morbidity of human immunodeficiency virus and other sexually transmitted diseases in Israel has not been established. 

Objectives: To compare the prevalence of STDs [1]among HIV[2]-positive patients to HIV-negative patients visiting an STD clinic in northern Israel. 

Methods: Between December 2000 and December 2001, 176 HIV-positive individuals (53% males) were screened and compared to 200 HIV-seronegative individuals (76% males). Demographics, symptomatology and risk factors were obtained via questionnaire. First-void urine samples were tested for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae. Serum was tested for type-specific herpes simplex virus-2, hepatitis B and syphilis. 

Results: Relative to the seronegative STD patients, HIV-positive patients exhibited significantly greater risk-reducing sexual behaviors such as consistent condom use [29/86 (33.7%) vs. 16/187 (8.6%), P < 0.001], and abstinence in the previous 6 months [43/125 (34%) vs. 7/185 (3.8%), P < 0.001]. Nevertheless, STD prevalence was higher among HIV-positive than HIV-negative patients (79.5% vs. 37.5%, P < 0.001). HSV[3]-2, syphilis and HBV[4] were more common among HIV-positive than HIV-negative patients [120/175 (68.8%)] vs. 18/200 (9%), P < 0.001)], [43/161 (26.7%) vs. 0%, P < 0.001)], [13/171 (7.6%) vs. 3/200 (1.5%), P < 0.01)], respectively. In contrast, Chlamydia and gonorrhea were more commonly found in HIV-negative patients than HIV-positive patients [3/176 (1.7%) vs.13/200 (6.5%), P < 0.05] vs. [0% vs.5/200 (2.5%), P < 0.05], respectively. 

Conclusion: Despite the low risk sexual behavior of Israeli HIV patients, they had a high prevalence of chronic STDs (e.g., HSV-2, HBV and syphilis). The lower prevalence of Chlamydia and gonorrhea among HIV-immunosuppressed patients may be attributed to routine antibiotic prophylaxis against opportunistic infections. Nevertheless, as advocated by international health organizations, it appears prudent to recommend the routine screening of these asymptomatic HIV-positive patients for STD pathogens. 


 




[1] STD = sexually transmitted diseases

[2] HIV = human immunodeficiency virus

[3] HSV = herpes simplex virus

[4] HBV = hepatitis B virus


Legal Disclaimer: The information contained in this website is provided for informational purposes only, and should not be construed as legal or medical advice on any matter.
The IMA is not responsible for and expressly disclaims liability for damages of any kind arising from the use of or reliance on information contained within the site.
© All rights to information on this site are reserved and are the property of the Israeli Medical Association. Privacy policy

2 Twin Towers, 35 Jabotinsky, POB 4292, Ramat Gan 5251108 Israel