Israel Medical Association Journal

Background: Health care workers bear the risk of both contracting influenza from patients and transmitting it to them. Although influenza vaccine is the most effective and safest public health measure against influenza and its complications, and despite recommendations that HCWs[1] should be vaccinated, influenza vaccination coverage among them remains low.

Objectives: To characterize influenza vaccination coverage and its determinants among employees in an Arab hospital in Israel.

Methods: An anonymous, self-administered questionnaire was distributed among employees involved in patient care in the winter of 2004–2005 at Nazareth Hospital in Israel. The questionnaire included items related to health demographic characteristics, health behaviors and attitudes, knowledge and attitude concerning influenza vaccination, and whether the respondent had received the influenza vaccine during the previous winter or any other winter.

Results: The overall rate of questionnaire return was 66%; 256 employees participated in the study. The immunization coverage rate was 16.4%, similar to that reported for other hospitals in Israel. Logistic regression analysis demonstrated a significant association only between influenza vaccination coverage and the presence of chronic illness and influenza vaccination in the past.

Conclusions: Influenza vaccination coverage among Nazareth Hospital health care workers was low. They did not view themselves as different to the general population with regard to vaccination. An intervention program was launched after the study period, aimed at increasing the knowledge on the efficacy and safety of the vaccine, stressing the importance of vaccinating HCWs, and administering the vaccine at the workplace. The program raised the vaccination coverage to 50%.

Background: Osler taught that splenic infarction presents with left upper abdominal quadrant pain, tenderness and swelling accompanied by a peritoneal friction rub. Splenic infarction is classically associated with bacterial endocarditis and sickle cell disease.

Objectives: To describe the contemporary experience of splenic infarction.

Methods: We conducted a chart review of inpatients diagnosed with splenic infarction in a Jerusalem hospital between 1990 and 2003.

Results: We identified 26 cases with a mean age of 52 years. Common causes were hematologic malignancy (six cases) and intracardiac thrombus (five cases). Only three cases were associated with bacterial endocarditis. In 21 cases the splenic infarction brought a previously undiagnosed underlying disease to attention. Only half the subjects complained of localized left-sided abdominal pain, 36% had left-sided abdominal tenderness 31% had no signs or symptoms localized to the splenic area, 36% had fever, 56% had leukocytosis and 71% had elevated lactate dehydrogenase levels. One splenectomy was performed and all patients survived to discharge. A post hoc analysis demonstrated that single infarcts were more likely to be associated with fever (20% vs. 63%, p < 0.05) and leukocytosis (75% vs. 33%, p = 0.06)

Conclusions: The clinical presentation of splenic infarction in the modern era differs greatly from the classical teaching, regarding etiology, signs and symptoms. In patients with unexplained splenic infarction, investigation frequently uncovers a new underlying diagnosis. 

Mesenchymal stem cells, or mesenchymal stromal cells, have emerged as a major new cell technology with a diverse spectrum of potential clinical applications. MSCs[1] were originally conceived as stem/progenitor cells to rebuild diseased or damaged tissues. Over the last 14 years, since the first report of MSC infusions in patients, the cells have been shown to suppress graft vs. host disease, stimulate linear growth in a genetic disorder of bone, and foster engraftment of haplo-identical hematopoietic stem cells. In all cases, few, if any, MSCs were identified at the site of clinical activity. This experience suggests a remarkable clinical potential, but a different general mechanism of action. Systemically infused MSCs seem to exert a therapeutic effect effect through the release of cytokines that act on local, or perhaps distant, target tissues. Rather than serving as stem cells to repair tissues, they serve as cellular factories that secrete mediators to stimulate the repair of tissues or other beneficial effects. Since both the tissue source of MSCs and the ex vivo expansion system may significantly impact the cytokine expression profile, these parameters may be critically important determinants of clinical activity. Furthermore, cell processing protocols may be developed to optimize the cell product for a specific clinical indication. For example, MSC-like cells isolated from placenta and expanded in a three-dimensional bioreactor have recently been shown to increase blood flow in critical limb ischemia. Future efforts to understand the cytokine expression profile will undoubtedly expand the range of MSC clinical applications.

Background: Experimental and clinical protocols are being developed for the cryopreservation of human hematopoietic progenitor cells. However, the effect of these procedures on the potential for HPC[1] to repopulate bone marrow is unknown.

Objectives: To examine the effect of cryopreservation on the ability of fetal human liver HPC, which include CD34+ cells and long-term culture-initiating cells, to repopulate immunodeficient non-obese diabetic/severe combined immunodeficiency mouse bone marrow.

Methods: Groups of sublethally irradiated NOD[2]/SCID[3] mice were injected intravenously with cryopreserved or freshly isolated fetal human liver HPC.

Results: Seven weeks after transplantation, flow cytometric analysis of bone marrow samples showed that mice that received the transplanted cells (either cryopreserved or freshly isolated) demonstrated both lymphoid and myeloid differentiation as well as the retention of a significant fraction of CD34+ cells. Conclusions: Cryopreserved fetal human liver-derived HPC appear to be capable of initiating human cell engraftment in NOD/SCID mouse bone marrow and open the possibility of using cryopreserved fetal human liver HPC for gene manipulation, gene transfusion therapy, and transplantation purposes.

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[1] HPC = hematopoietic progenitor cells

[2] NOD = non-obese diabetic

[3] SCID = severe combined immunodeficiency