Annals of the New York Academy of Sciences
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Patients with thalassemia major accumulate body iron over time as a consequence of continuous red blood cell transfusions which cause hepatic, endocrine, and cardiac complications. Despite the availability of three iron chelators, some patients fail to respond adequately to monotherapy with any of them. Combination therapy, consisting in the use of two chelators on the same day, has been introduced to increase the efficacy and to induce negative iron balance in patients with severe iron overload. ⋯ Side effects, though significant, are manageable if properly monitored. Preliminary promising results have been obtained using combined chelation with deferasirox and DFO. As more drug combination regimes are evaluated, it should be possible to better tailor iron chelation to the needs of the patients, minimizing toxicity and maximizing efficacy throughout life.
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Ann. N. Y. Acad. Sci. · Aug 2010
Progress in hematopoietic stem cell transplantation as allogeneic cellular gene therapy in thalassemia.
Allogeneic hemopoietic stem cell transplantation (HSCT) represents one of the best cures for thalassemia. Currently, HSCT for thalassemia consists of allogeneic stem cell gene therapy and still awaits autologous genetically modified stem cell transplantation. HSCT for thalassemia has substantially improved over the last two decades, due in large part to improvements in preventive strategies, the effective control of transplant-related complications, and the development of new preparative regimens. ⋯ Adult thalassemia patients, who are higher risk patients for transplant-related toxicity due to an advanced phase of the disease, have a cure rate of 65% with current treatment protocol. Patients who do not have matched family or unrelated donors could benefit from haploidentical mother-to-child transplantation. Overall, the results of this type of transplantation appear encouraging.
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Ann. N. Y. Acad. Sci. · Aug 2010
Detection of the cardiovascular complications of thalassemia by echocardiography.
The thalassemia syndromes are associated with cardiovascular complications, which differ with the varying phenotypes encountered. The well-recognized paradigm of heart failure induced by myocardial iron overload, in thalassemia major (TM), has now been joined by pulmonary arterial hypertension (mostly seen in thalassemia intermedia) among other more subtle disorders of the cardiovascular system, including endothelial dysfunction. ⋯ Echocardiography remains an indispensable tool in the cardiovascular assessment of patients, it provides many insights into cardiovascular function, and its use allows improved management of patients. It is particularly suited to assess diastolic function, diagnose intracardiac masses (usually thrombus), and assess right ventricular function and pulmonary pressure.
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Ann. N. Y. Acad. Sci. · Jun 2010
Presynaptic inhibition of primary afferents by depolarization: observations supporting nontraditional mechanisms.
Primary afferent neurotransmission is the fundamental first step in the central processing of sensory stimuli and is controlled by pre- and postsynaptic inhibitory mechanisms. Presynaptic inhibition (PSI) is probably the more powerful form of inhibitory control in all primary afferent fibers. A major mechanism producing afferent PSI is via a channel-mediated depolarization of their intraspinal terminals, which can be recorded extracellularly as a dorsal root potential (DRP). ⋯ There is still no "squeaky clean" evidence of this organization. This paper describes recent and historical work that supports the existence of PAD occurring by more direct pathways and with a complex pharmacology that questions the proprietary role of GABA and GABA(A) receptors in this process. Cholinergic transmission in particular may contribute significantly to PAD, including via direct release from primary afferents.
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Ann. N. Y. Acad. Sci. · Jun 2010
Timing versus duration: determinants of anesthesia-induced developmental apoptosis in the young mammalian brain.
Rapidly accumulating evidence indicates that clinically used general anesthesia causes massive, widespread neuroapoptotic degeneration in the developing mammalian brain. Susceptibility to anesthesia-induced neurotoxicity has been documented in rats, mice, guinea pigs, primates, and in this study, piglets; in short, anesthesia-induced developmental neuroapoptosis is not species-dependent. ⋯ However, the highly reproducible findings in different species also indicate that the timing of exposure to anesthesia is critically important; that is, brain regions that are at the peak of synaptogenesis are most vulnerable even when the exposure to anesthesia is relatively brief. Because the peak of synaptogenesis is characterized by intense, highly programmed neuronal communication that is vital for the survival and proper function of immature neurons, we conclude that anesthesia causes severe disturbances in the fine equilibrium between excitatory and inhibitory neurotransmission in the developing mammalian brain, ultimately leading to neuronal redundancy and death.