Drug news & perspectives最新文献

Fifty years ago, the issue of conflict of interest in biomedical research appeared in the national spotlight and has remained in a state of constant evolution. Government legislation caused a boom in collaborations between physicians, researchers, academic institutions and industry. These relationships continue to advance medical science and make meaningful progress, yet they may threaten the integrity of physicians and researchers and the public's trust in medicine. This article will highlight the evolution of industry relationships and conflict of interest over time, discuss methods by which industry can potentially exert effects and propose new directions for the future.

It seems likely that some infants who die from sudden infant death syndrome (SIDS) have a brainstem abnormality of the serotonergic system. Evidence suggests that infants who died from SIDS had defective respiratory and/or autonomic responses that led to death instead of recovery after an acute insult. The serotonergic neuromodulator system has roles in the control of cardiac autonomic and respiratory function, as well as now being identified as abnormal in infants with SIDS. This manuscript reviews the multiple roles of serotonin with reference to the functional aspects of the relevant brain regions. Correlations with pre- or postnatal exposure to stressors, or an underlying genetic process are also reviewed. Together, these studies indicate that perturbed function of the serotonin system will have significant physiological impact during early development. Understanding the functional importance of these systems assists understanding of the pathogenesis of SIDS. In conclusion, whether an infant inherits serotonergic defects and is therefore "inherently vulnerable", or whether postnatal stressors can induce the abnormalities, any functional abnormalities of the serotonergic system that result are likely to be subclinical in the majority of cases and not easily detected with current medical tools.

The pursuit of personalized medicine requires the development of biomarkers to predict disease course, monitor disease evolution, stratify patient subgroups by disease activity and to predict and monitor response to therapies. Multiple sclerosis (MS) is a common neurological disease in young adults with an unpredictable course that may be associated with significant disability, diminishing the patient's quality of life. Currently, disease prognosis is based on clinical information (relapse rate and disability scales) and diagnostic tests (brain MRI or the presence of oligoclonal bands in the cerebrospinal fluid). However, the ability of neurologists to make an accurate prognosis is very limited based on such information, a situation perceived by patients as one of their biggest concerns. Although many recent studies have identified different molecules and imaging techniques associated with the course of MS, in most cases the diagnostic accuracy of such technologies has not been properly assessed. This shortcoming is partly due to the failure to validate such biomarkers, which impedes their application in clinical practice. However, the recent validation of anti-aquaporin-4 antibodies for Devic's disease and the development of optic coherent tomography for MS, are examples of the benefits that the development of MS biomarkers can offer. Indeed, it may currently be necessary to redress the bias in research towards clinical validation rather than discovery in order to promote translational research and improve patient's quality of life.

DC-SIGN (dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin), a C-type lectin mainly present at the surface of immature dendritic cells, plays a relevant role activating and tailoring adaptive immune responses against different pathogens. This lectin recognizes, in a multivalent and calcium-dependent manner, highly glycosylated proteins present at the surface of pathogens. Several groups have devoted remarkable efforts to develop carbohydrate multivalent compounds targeting this lectin to modulate its role in pathogen capture and in the generation of an immune response. Most of these approaches have been based on mannosylation of immunogenic proteins such as ovalbumin but new strategies have been envisaged to achieve these goals. Although mannosylated systems cannot provide the required selectivity for a specific lectin at dendritic cells, fucosylated compounds have overcome this problem specifically targeting DC-SIGN and avoiding interferences with other lectins, such as the mannose receptor. The use of these carbohydrate multivalent compounds to target DC-SIGN can be considered a promising strategy to inhibit pathogen entry and to develop new vaccines against pathogen infection or cancer. New studies are required to provide more insights into the complex immune pathway involving DC-SIGN.

Excess activation of ionotropic glutamate receptors, primarily N-methyl-D-aspartate (NMDA) receptors and free radicals, evoke nerve cell death following hypoxic-ischemic brain injury in various animal models. However, clinical trials in stroke patients using NMDA receptor antagonists have failed to show efficacy primarily due to the limited therapeutic time window for neuroprotection and a narrow therapeutic index. In comparison, antioxidants prolonged the time window for neuroprotection in animal models of ischemic stroke and showed greater therapeutic potential in clinical trials for ischemic stroke. Excess activation of NMDA receptors and free radicals mediate the two separate pathways of nerve cell death in stroke and a safe and multifunctional drug that can block both routes in the brain will likely provide a better therapeutic outcome in patients with stroke. Derivatives of the lead structures of sulfasalazine and aspirin have led to the discovery of a new molecule, Neu2000, that has demonstrated excellent neuroprotection against NMDA- and free radical-induced cell death. Neu2000 is an NR2B-selective, moderate NMDA receptor antagonist with potent cell-permeable, spin trapping antioxidant action even at nanomolar concentrations. Nonclinical and human phase I studies demonstrated that Neu2000 can be translated to treat patients with stroke with better efficacy and therapeutic time window.

This review evaluates past and present clinical trials, as well as the current preclinical drug candidates focused on treating Alzheimer's disease (AD), in order to better assess the trends in AD drug discovery in context with specific drug mechanisms. The author begins by presenting a summary of the results of over 160 clinical trials targeted at AD, of which 52% have either failed to meet clinical endpoints or stalled (defined for the purpose of this review as no clinical or publicly mentioned progress for at least 3 years). The author postulates that many of the current clinical approaches fail to sufficiently regulate the amyloid cascade that includes, but is not limited to, the production of soluble β-amyloid precursor protein, β-amyloid and/or amyloid precursor protein intracellular domain and including activation of the tau cascade, ultimately translating to no improvement in cognitive function. To support this argument, the author compares clinical results and peer-reviewed opinions to postulate that appropriately focused multifunctional or dual pathway drugs could make the optimal candidate(s) for further investigations.

Des-γ-carboxy prothrombin (DCP) is an abnormal prothrombin induced by the absence of vitamin K₂ that is increased in the serum of patients with hepatocellular carcinoma (HCC). In hepatoma cells, genetic alterations, membrane receptors, the inability to uptake labeled low-density lipoprotein, cytoskeletal changes and hepatocyte cytoplasmic transfers involved in vitamin K metabolism could play an important role in producing detectable DCP serum levels. Serum DCP was found to have a sensitivity ranging from 48% to 62%, a specificity of 81% to 98% and a diagnostic accuracy of 59% to 84% for detecting HCC. Plasma DCP does not correlate with α-fetoprotein (AFP) levels. However, when used together, the DCP and AFP assays increase the sensitivity of detecting HCC in more than 85% of patients. The specificity of the DCP assay appears to be superior to that of AFP. These biomarkers can complement ultrasound for early HCC detection, but neither DCP nor AFP is optimal. For small HCC, a high preoperative DCP level appears to be indicative of tumor recurrence. Recently, there has been attention given to DCP because of its role in detecting HCC recurrence after living donor liver transplant. More recent research has demonstrated that DCP stimulates human vascular endothelial cell growth and migration. All the data presented above demonstrate the importance of DCP in formulating a prognosis for patients with HCC.

Many new therapeutic compounds have been developed that target malignancies and other disorders of the brain. However, delivering these compounds to diseased tissue remains a difficult challenge. One option for local drug delivery in the brain is direct infusion of the compounds through a catheter into the brain parenchyma. Over the last decade, new infusion catheters have been developed to improve this delivery method. Some of these catheters are needles or cannulas that have been modified specifically to increase the infusion rate that can be achieved without leakage of the infusate out of the brain. Other new catheters have been fabricated using micromachining techniques adapted from electronics manufacturing. These microfabricated catheters can achieve comparable infusion rates as standard needles, but they also can incorporate features that would be difficult to build into needles or cannulas to improve drug delivery. This article reviews the development of these devices, their performance in preclinical studies and their potential benefits to neural drug delivery.