罕见疾病及孤儿药物研究现状及进展

文中简述了罕见疾病的定义、发病原因、分类,总结了国内外罕见疾病研究和孤儿药物研发的现状,分析了生物技术的研究手段在罕见疾病药物研发方面的应用,进一步阐述了罕见疾病研究和孤儿药物开发的必要性和紧迫性,对推动科学技术的进步和人类健康事业的发展具有深远的意义。     

Database identifies FDA-approved drugs with potential to be repurposed for treatment of orphan diseases

Facing substantial obstacles to developing new therapies for rare diseases, some sponsors are looking to 'repurpose' drugs already approved for other conditions and use those therapies to treat rare diseases. In an effort to facilitate such repurposing and speed the delivery of new therapies to people who need them, we have established a new resource, the Rare Disease Repurposing Database (RDRD). The advantages of repurposed compounds include their demonstrated efficacy (in some clinical contexts), their observed toxicity profiles and their clearly described manufacturing controls. To create the RDRD, we matched the US Food and Drug Administration (FDA) orphan designation database to FDA drug and biological product approval lists. The RDRD lists 236 products that have received orphan status designation--that is, were found to be 'promising' for the treatment of a rare disease--and though not yet approved for marketing for that rare disease, they are already approved for marketing to treat some other disease or condition. The RDRD contains three tables: Orphan-designated products with at least one marketing approval for a common disease indication (N = 109); orphan-designated products with at least one marketing approval for a rare disease indication (N = 76); and orphan-designated products with marketing approvals for both common and rare disease indications (N = 51). While the data included in the database is a re-configuration/cross-indexing of information already released by the FDA, it offers sponsors a new tool for finding special opportunities to develop niche therapies for rare disease patients.     

Drug repositioning for orphan diseases

The need and opportunity to discover therapeutics for rare or orphan diseases are enormous. Due to limited prevalence and/or commercial potential, of the approximately 6000 orphan diseases (defined by the FDA Orphan Drug Act as <200 000 US prevalence), only a small fraction (5%) is of interest to the biopharmaceutical industry. The fact that drug development is complicated, time-consuming and expensive with extremely low success rates only adds to the low rate of therapeutics available for orphan diseases. An alternative and efficient strategy to boost the discovery of orphan disease therapeutics is to find connections between an existing drug product and orphan disease. Drug Repositioning or Drug Repurposing--finding a new indication for a drug--is one way to maximize the potential of a drug. The advantages of this approach are manifold, but rational drug repositioning for orphan diseases is not trivial and poses several formidable challenges--pharmacologically and computationally. Most of the repositioned drugs currently in the market are the result of serendipity. One reason the connection between drug candidates and their potential new applications are not identified in an earlier or more systematic fashion is that the underlying mechanism 'connecting' them is either very intricate and unknown or indirect or dispersed and buried in an ever-increasing sea of information, much of which is emerging only recently and therefore is not well organized. In this study, we will review some of these issues and the current methodologies adopted or proposed to overcome them and translate chemical and biological discoveries into safe and effective orphan disease therapeutics.     

The gene is not dead, merely orphaned and seeking a home

SUMMARY Despite announcements and obituaries, news of the death of the gene has been greatly exaggerated, or so says the gene as it struggles to survive and find a safe haven from which to steer its course through development and evolution. In this short piece, I consider recent claims that the gene is dead. I conclude that the gene is alive and well, living and functioning in the cell, which is both its natural home and a fundamental unit of evo-devo.     

Chitotriosidase,a prematurely orphan enzyme

Human Chitotriosidase (CHIT) is a member of the chitinase family and is synthesized by activated macrophages. Recently, a genetic polymorphism was found to be responsible for the common deficiency in CHIT activity, frequently encountered in different population. We analyzed the CHIT gene in some ethnic groups from Mediterranean and frican area, to evaluate whether the CHIT gene polymorphism correlates with the changes in environmental features and the disappearance of parasitic diseases. We evaluate the plasma CHIT activity and analyzed, by PCR, the Chit gene polymorphism in 100 Sicilian, 107 Sardinian and 99 Sub-Saharan subjects. We found an heterozygote frequency for a duplication of 24 base pair in exon 10 of 44,54% in Sicily and 32,71 % in Sardinia, whereas homozygous chit deficient were 5,45 % and 3,73%, respectively. On the contrary in Burkina Faso, a mesoendemic regio nforPlasmodium falciparum malaria and other intestinal parasites, a low incidence of CHIT mutation was found (heterozygous 2%) and any subject was homozygous for CHIT deficiency. Our results suggest that in sub-Saharan population the intact CHIT gene seems essential for sustaining resistance against chitin-coated parasitic disease, whereas the presence of CHIT gene polymorphism in Mediterranean population could be the result of a recent positive selection due to improved environmental conditions, which makes prematurely orphan this enzyme.     

Rare diseases of the posterior urethra in males

Rare diseases of the posterior urethra and adjacent structures in adult men are presented. Anatomy and embryology of this segment of urethra, pathologies, diagnosis and therapy are also discussed.     

Addictive drugs and their relationship with infectious diseases

The use of drugs of abuse, both recreationally and medicinally, may be related to serious public health concerns. There is a relationship between addictive drugs of abuse such as alcohol and nicotine in cigarette smoke, as well as illegal drugs such as opiates, cocaine and marijuana, and increased susceptibility to infections. The nature and mechanisms of immunomodulation induced by such drugs of abuse are described in this review. The effects of opiates and marijuana, using animal models as well as in vitro studies with immune cells from experimental animals and humans, have shown that immunomodulation induced by these drugs is mainly receptor-mediated, either directly by interaction with specific receptors on immune cells or indirectly by reaction with similar receptors on cells of the nervous system. Similar studies also show that cocaine and nicotine have marked immunomodulatory effects, which are mainly receptor-mediated. Both cocaine, an illegal drug, and nicotine, a widely used legal addictive component of cigarettes, are markedly immunomodulatory and increase susceptibility to infection. The nature and mechanism of immunomodulation induced by alcohol, the most widely used addictive substance of abuse, are similar but immunomodulatory effects, although not receptor-mediated. The many research studies on the effects of these drugs on immunity and increased susceptibility to infectious diseases, including AIDS, are providing a better understanding of the complex interactions between immunity, infections and substance abuse.     

Enteroviruses: Classification,diseases they cause,and approaches to development of antiviral drugs

The genus Enterovirus combines a portion of small (+)ssRNA-containing viruses and is divided into 10 species of true enteroviruses and three species of rhinoviruses. These viruses are causative agents of the widest spectrum of severe and deadly epidemic diseases of higher vertebrates, including humans. Their ubiquitous distribution and high pathogenici- ty motivate active search to counteract enterovirus infections. There are no sufficiently effective drugs targeted against enteroviral diseases, thus treatment is reduced to supportive and symptomatic measures. This makes it extremely urgent to develop drugs that directly affect enteroviruses and hinder their development and spread in infected organisms. In this review, we cover the classification of enteroviruses, mention the most common enterovirus infections and their clinical man- ifestations, and consider the current state of development of anti-enteroviral drugs. One of the most promising targets for such antiviral drugs is the viral Internal Ribosome Entry Site (IRES). The classification of these elements of the viral mRNA translation system is also examined.