Israel Medical Association Journal

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.

The incidence of aortic valve stenosis is growing rapidly in the elderly. Nonetheless, many symptomatic patients are not referred for surgery usually because of high surgical risk. Unfortunately, percutaneous balloon valvuloplasty is unsatisfactory due to high recurrence rates. In 2002, Cribier and colleagues were the first to describe percutaneous aortic valve implantation, opening a new era of aortic stenosis management. In the present review we report a patient treated by this novel method, discuss and assess how it is implanated, report the findings of studies conducted to date, and suggest future directions for percutaneous treatment of aortic valve disease.
 

Background: The role of endoscopic ultrasound in evaluating the response of esophageal cancer to neoadjuvant chemotherapy is controversial.

Objectives: To evaluate the accuracy of EUS[1] in restaging patients who underwent NAC[2].

Methods: The disease stage of patients with esophageal cancer was established by means of the TNM classification system. The initial staging was determined by chest and abdominal computed tomography and EUS. Patients who needed NAC underwent a preoperative regimen consisting of cisplatin and fluouracil. Upon completion of the chemotherapy, patients were restaged and then underwent esophagectomy. The results of the EUS staging were compared with the results of the surgical pathology staging. This comparison was done in two groups of patients: the study group (all patients who received NAC) and the control group (all patients who underwent primary esophagectomy without NAC).

Results: NAC was conducted in 20 patients with initial stage IIB and III carcinoma of the esophagus (study group). Post-chemotherapy EUS accurately predicted the surgical pathology stage in 6 patients (30%). Pathological down-staging was noted in 8 patients (40%). However, the EUS was able to observe it in only 2 patients (25%). The accuracy of EUS in determining the T status alone was 80%. The accuracy for N status alone was 35%. In 65% of examinations the EUS either overestimated (35%) or underestimated (30%) the N status. Thirteen patients with initial stage I-IIA underwent primary esophagectomy after the initial staging (control group). EUS accurately predicted the surgical pathology disease stage in 11 patients (85%).

Conclusions: EUS is an accurate modality for initial staging of esophageal carcinoma. However, it is not a reliable tool for restaging esophageal cancer after NAC and it cannot predict response to chemotherapy.

Background: High levels of plasma homocysteine constitute a risk for cardiovascular disease. Physical activity, known to reduce CVD[1] risk, has been related to levels of Hcy[2]. Recently, higher Hcy was shown to be associated with lower cardiovascular fitness in women but not in men.

Objectives: To further explore the relationship between cardiorespiratory fitness and plasma total homocysteine levels in a large cohort of adult males and females.

Methods: This cross-sectional study included 2576 fitness and Hcy examinations in adults (62% males) aged 30–59 years, randomly drawn from a population undergoing a periodic health examination in the Sheba Medical Center's Executive Screening Survey. Blood tests were collected for tHcy[3] and a sub-maximal exercise test was performed to estimate cardiorespiratory fitness. Information on CVD/CVD risk factors (coronary heart disease, cerebrovascular accident, diabetes, hypertension or dyslipidemia) was self-reported.

Results: Mean tHcy plasma levels were 14.4 ± 7.7 and 10.2 ± 3.0 µmol/ml, and mean maximal oxygen uptake 36.5 ± 11.7 and 29 2 ± 9.5 ml/kg/min for males and females, respectively. A multiple regression analysis, adjusting for age, body mass index and CVD/CVD risk factors, showed no association between cardiorespiratory fitness and level of tHcy in males (P = 0.09) or in females (P = 0.62).

Conclusions: In this sample no relationship was found between level of cardiorespiratory fitness and plasma tHcy in men or women. The inconsistency of findings and the small number of studies warrant further research of the association between cardiorespiratory fitness and tHcy, an association that may have clinical implications for the modifications of cardiovascular risk factors.

Primary biliary cirrhosis is an autoimmune cholestatic liver disease characterized by humoral and cellular response directed at mitochondrial autoantigens, mainly the E2 component of the pyruvate dehydrogenase complex. The etiology of PBC[1], like most polygenic autoimmune diseases, belongs to the "complex" category, including genetic elements and environmental factors. Many environmental factors, such as xenobiotics, smoking, hormonal therapy, toxins, oxidative stress and recurrent urinary tract infections, are associated with PBC. Infectious agents can trigger autoimmunity via several mechanisms and are associated with various autoimmune diseases. A relationship between PBC and several infectious agents, and a possible role for Escherichia coli in the pathogenesis of PBC has been suggested. The identification of a culprit agent that induces or exacerbates PBC might have diagnostic and therapeutic implications. This review evaluates the evidence for an infectious agent role in the pathogenesis of PBC.

Objectives: To evaluate the incidence and comparative frequency of clinical manifestations in different etiologic-pathogenic variants of RTD[1] in Israel and in summarized published data.

Methods: Stillborn and neonatal autopsy material from nine medical centers in northern and central Israel was studied. Information concerning pregnancy, labor and postnatal status and autopsy findings of cases with histologically, histochemically and immunohistochemically confirmed RTD were obtained from corresponding reports and from published material.

Results: From the 1538 autopsies of fetuses (≥ 20 weeks gestation) and neonates that were performed between 1976 and 2007 we identified 12 cases of RTD (0.78%). Abnormality occurred more often (1.4%) in the Upper and Western Galilee than in Israel as a whole.

Conclusions: Our study and a review of the literature showed that the autosomal recessive variant of RTD was more frequent than twin-twin transfusion induced. Most symptoms were similar in all variants of RTD, but their frequency was different in each of them.

Background: Dyslipidemia remains underdiagnosed and undertreated in patients with coronary artery disease. The Computer-based Clinical Decision Support System provides an opportunity to close these gaps.

Objectives: To study the impact of computerized intervention on secondary prevention of CAD[1].

Methods: The CDSS[2] was programmed to automatically detect patients with CAD and to evaluate the availability of an updated lipoprotein profile and treatment with lipid-lowering drugs. The program produced automatic computer-generated monitoring and treatment recommendations. Adjusted primary clinics were randomly assigned to intervention (n=56) or standard care arms (n=56). Reminders were mailed to the primary medical teams in the intervention arm every 4 months updating them with current lipid levels and recommendations for further treatment. Compliance and lipid levels were monitored. The study group comprised all patients with CAD who were alive at least 3 months after hospitalization.

Results: Follow-up was available for 7448 patients with CAD (median 19.8 months, range 6–36 months). Overall, 51.7% of patients were adequately screened, and 55.7% of patients were compliant with treatment recommended to lower lipid level. A significant decrease in low density lipoprotein levels was observed in both arms, but was more pronounced in the intervention arm: 121.9 ± 34.2 vs. 124.3 ± 34.6 mg/dl (P < 0.02). A significantly lower rate of cardiac rehospitalizations was documented in patients who were adequately treated with lipid-lowering drugs, 37% vs. 40.9% (P < 0.001).

Conclusions: This initial assessment of our data represent a real-world snapshot where physicians and CAD patients often do not adhere to clinical guidelines, presenting a major obstacle to implementing effective secondary prevention. Our automatic computerized reminders system substantially facilitates adherence to guidelines and supports wide-range implementation.

Organophosphate and carbamate are mainly used to kill insects, thereby protecting livestock, crops, homes and communities. Yet, these compounds also convey great danger. OP[1] and CRB[2] poisoning is an important clinical problem, often life-threatening, especially in the pediatric population in rural areas where reaching a physician or hospital on time is difficult. We present a summary of accumulated toxicological knowledge as well as clinical and laboratory experience from a medical center serving a relatively vast rural area and pediatric population. We stress the importance of knowing how to recognize the classic signs of OP and CRB poisoning and when it is appropriate to investigate for such poisoning even in the absence of those signs. Like any medical emergency, OP and CRB poisoning requires prompt resuscitation and use of antidotes. Atropine, oxygen and fluids are the mainstay of therapy. Oximes, which were found useful in some cases of OP poisoning and useless in some cases of CRB poisoning, are absolutely safe as empiric treatment, which is often needed since the major differential diagnosis of OP poisoning is CRB poisoning that is clinically indistinguishable. We hope that continuing research will offer further insights into the management of such events, and we are confident that improved medical management of OP and CRB poisoning will result in a reduction of morbidity and other complications associated with intensive care procedures and hospitalization. 

Background: Manganism is a central nervous system disorder caused by toxic exposure to manganese. Manganism has been related to occupational exposures, liver diseases, prolonged parenteral nutrition, and abuse of illicit drugs. Initially manifested by a reversible neuropsychiatric syndrome (locura manganica), the main symptoms and signs of manganism are emotional lability, compulsive behavior and visual hallucinations. Locura manganica is followed by an irreversible extrapyramidal syndrome, the onset of which occurs years after chronic exposure.

Objectives: To characterize the regional distribution of Mn[1] in the rat brain after subchronic exposure to Mn. This animal model holds special clinical relevance, reflecting the earlier clinical stages of manganism before chronic exposure to Mn exerts its irreversible effects.

Methods: Sprague-Dawley rats were intravenously injected with MnCl₂ weekly, for a total of 14 weeks – approximately 1/10 of the lifetime of the rat. T1-weighted magnetic resonance imaging was used to detect the distribution of Mn deposition in brain tissues, as evidenced by areas of T1-weighted hyperintense signals.

Results: A consistent region-specific pattern of T1-weighted hyperintensities was observed in the brains of Mn-treated rats. Cortical hyperintensities were prominent in the hippocampus and dentate gyrus. Hyperintensities were also observed in the olfactory bulbs, pituitary gland, optic nerves and chiasma, pons, midbrain tegmentum, habenula, lentiform and caudate nuclei, thalamus, chorioid plexus and cerebellar hemispheres.

Conclusions: Prominent Mn depositions, evidenced by T1-weighted hyperintensities in the hippocampus after subacute exposure to Mn, are compatible with the clinical picture of manganism during its early stages; and may explain its pathophysiology.