The hematopoietic stem cell (HSC) is a unique cell positioned highest in the hematopoietic hierarchical system. The HSC has the ability to stay in quiescence, to self-renew, or to differentiate and generate all lineages of blood cells. The path to be actualized is influenced by signals that derive from the cell’s microenvironment, which activate molecular pathways inside the cell. Signaling pathways are commonly organized through inducible protein–protein interactions, mediated by adaptor proteins that link activated receptors to cytoplasmic effectors. This review will focus on the signaling molecules and how they work in concert to determine the HSC’s fate.
Extracellular vesicles (EVs), comprised of exosomes, microparticles, apoptotic bodies, and other microvesicles, are shed from a variety of cells upon cell activation or apoptosis. EVs promote clot formation, mediate pro-inflammatory processes, transfer proteins and miRNA to cells, and induce cell signaling that regulates cell differentiation, proliferation, migration, invasion, and apoptosis. This paper will review the contribution of EVs in hematological disorders, including hemoglobinopathies (sicklecell disease, thalassemia), paroxysmal nocturnal hemoglobinuria, and hematological malignancies (lymphomas, myelomas, and acute and chronic leukemias).
The recognition that the development of cancer is associated with acquired immunodeficiency, mostly against cancer cells themselves, and understanding pathways inducing this immunosuppression, has led to a tremendous development of new immunological approaches, both vaccines and drugs, which overcome this inhibition. Both “passive” (e.g. strategies relying on the administration of specific T cells) and “active” vaccines (e.g. peptide-directed or whole-cell vaccines) have become attractive immunological approaches, inducing cell death by targeting tumor associated antigens. Whereas peptide-targeted vaccines are usually directed against a single antigen, whole-cell vaccines (e.g. dendritic cell vaccines) are aimed to induce robust responsiveness by targeting several tumor-related antigens simultaneously. The combination of vaccines with new immuno-stimulating agents which target “immunosuppressive checkpoints” (anti-CTLA-4, PD-1, etc.) is likely to improve and maintain immune response induced by vaccination.
Non-Hodgkin lymphoma (NHL) is one of the most common hematologic malignancies worldwide. The incidence of NHL has been rising for several decades; however, in the last 20 years, it reached a plateau. NHL incidence among males is significantly higher than in females. In addition to gender itself, gravidity has a protective role against NHL occurrence. Gender also matters in terms of NHL clinical characteristics. For example, female predominance was found in three extra-nodal sites (the breast, thyroid, and the respiratory system) occasionally involved in NHL. The diagnosis of NHL during pregnancy is associated with a unique clinical behavior. It is usually diagnosed in the second or third trimester and in advanced stage. Furthermore, the histological subtype is highly aggressive, and reproductive organ involvement is common. The reduced rate of NHL among females may be explained by direct effects of estrogens on lymphoma cell proliferation or by its effect on anti-tumor immune response. Gender has an important role in responsiveness to standard B cell NHL treatment. Among older adults, women benefited more from the addition of the anti-CD20 antibody rituximab to standard chemotherapy regimens. This phenomenon can be explained by the difference in clearance rate of rituximab that was found to be significantly lower among older females than older males. In mantle cell lymphoma, women receiving lenalidomide have higher rates of response. An understanding of the mechanisms responsible for gender-associated NHL differences will ultimately improve the clinical approach, allowing for a more accurate assessment of prognosis and patient-tailored treatment.
The endocannabinoid system is involved in a host of homeostatic and physiologic functions, including modulation of pain and inflammation. The specific roles of currently identified endocannabinoids that act as ligands at endogenous cannabinoid receptors within the central nervous system (primarily but not exclusively CB1 receptors) and in the periphery (primarily but not exclusively CB2 receptors) are only partially elucidated, but they do exert an influence on nociception. Exogenous plant-based cannabinoids (phytocannabinoids) and chemically related compounds, like the terpenes, commonly found in many foods, have been found to exert significant analgesic effects in various chronic pain conditions. Currently, the use of Δ9-tetrahydrocannabinol is limited by its psychoactive effects and predominant delivery route (smoking), as well as regulatory or legal constraints. However, other phytocannabinoids in combination, especially cannabidiol and β-caryophyllene, delivered by the oral route appear to be promising candidates for the treatment of chronic pain due to their high safety and low adverse effects profiles. This review will provide the reader with the foundational basic and clinical science linking the endocannabinoid system and the phytocannabinoids with their potentially therapeutic role in the management of chronic pain.
In August of 2014, Manduca P et al. published “An open letter for the people in Gaza” in The Lancet. This letter was the response of those authors to their perspective of what was happening in Gaza during the summer-long conflict between Israel and Gaza. Israel was finally responding to years of bombardment from Gaza into civilian areas in the south of Israel. Two of the authors of the letters were known anti-Semites, and held connections with David Duke, a former Ku Klux Klan Grand Wizard in Louisiana and advocate of Nazism. Both these authors expressed sympathy and support for Duke’s rabidly anti-Jewish positions. In their letter they accused Israel’s medical community of complicity in committing terrible atrocities and even implied that chemical warfare was being used by Israel.
The “curative potential” in almost any clinical setting depends on a caregiver establishing and maintaining an empathic connection with patients so as to achieve “narrative competence” in discerning and acting in accord with their preferences and best interests. The “narrative medicine” model of shared “close reading of literature and reflective writing” among clinicians as a means of fostering a capacity for clinical empathy has gained validation with recent empirical studies demonstrating the enhancement of theory of mind (ToM), broadly conceived as empathy, in readers of literary fiction. Talmudic legends, like that of Rabbi Judah’s death, are under-appreciated, relevant sources of literary fiction for these efforts. The limitations of narrative medicine are readily counterbalanced by simultaneously practiced attention to traditional bioethical principles, including—especially—beneficence, non-maleficence, and autonomy.
Professionalism is a core competency of physicians. Clinical knowledge and skills (and their maintenance and improvement), good communication skills, and sound understanding of ethics constitutes the foundation of professionalism. Rising from this foundation are behaviors and attributes of professionalism: accountability, altruism, excellence, and humanism, the capstone of which is professionalism. Patients, medical societies, and accrediting organizations expect physicians to be professional. Furthermore, professionalism is associated with better clinical outcomes. Hence, medical learners and practicing physicians should be taught and assessed for professionalism. A number of methods can be used to teach professionalism (e.g. didactic lectures, web-based modules, role modeling, reflection, interactive methods, etc.). Because of the nature of professionalism, no single tool for assessing it among medical learners and practicing physicians exists. Instead, multiple assessment tools must be used (e.g. multi-source feedback using 360-degree reviews, patient feedback, critical incident reports, etc.). Data should be gathered continuously throughout an individual’s career. For the individual learner or practicing physician, data generated by these tools can be used to create a “professionalism portfolio,” the totality of which represents a picture of the individual’s professionalism. This portfolio in turn can be used for formative and summative feedback. Data from professionalism assessments can also be used for developing professionalism curricula and generating research hypotheses. Health care leaders should support teaching and assessing professionalism at all levels of learning and practice and promote learning environments and institutional cultures that are consistent with professionalism precepts.
Combat trauma may affect servicemen from indigenous, traditional communities in ways that warrant special attention. The Bedouins, who enlist in the Israel Defense Forces (IDF) voluntarily, represent a unique, closed, collectivist cultural minority, potentially in a predicament in light of ongoing sociopolitical events. This paper summarizes findings and lessons learned from a community study of Bedouin IDF servicemen and their families residing in Israel’s Western Galilee. This is the only research endeavor to have addressed trauma exposure and posttraumatic reactions in this community. The sampling strategies and interview schedule were designed in consideration of participation barriers typical of hard-to-reach populations. Data collection followed an extended phase of liaising with key informants and building trust. Study limitations are discussed in terms of the challenges presented by this type of research. Interviews conducted with 317 men, 129 wives, and 67 mothers revealed high levels of trauma exposure and posttraumatic stress disorder (PTSD) in the men, and related distress in wives and mothers, but not in the children. The role of aggression in mediating the impact of PTSD and concepts such as shame, the loss of personal resources, and beliefs about retribution are highlighted as key issues for a culturally relevant understanding of traumatized indigenous communities.
Essential monoclonal gammopathy is usually an asymptomatic condition, the characteristics of which have been defined over approximately 70 years of study. It has a known population-attributable risk of undergoing clonal evolution to a progressive, symptomatic B-cell neoplasm. In a very small fraction of patients, the monoclonal immunoglobulin has biophysical characteristics that can lead to tissue deposition syndrome (e.g. Fanconi renal syndrome) or, by chance, have characteristics of an autoantibody that may inactivate critical proteins (e.g. acquired von Willebrand disease). In this report, we describe the very uncommon forms of ocular injury that may accompany essential monoclonal gammopathy, which include crystalline keratopathy, crystal-storing histiocytosis, hypercupremic keratopathy, and maculopathy. The first three syndromes result from uncommon physicochemical alterations of the monoclonal immunoglobulin that favor crystallization or exaggerated copper binding. The last-mentioned syndrome is of uncertain pathogenesis. These syndromes may result in decreased visual acuity. These ocular findings may lead, also, to the diagnosis of monoclonal gammopathy.
