Current Drug Targets - Volume 14, Issue 8, 2013

Abnormal luteal function is a common issue in assisted reproduction techniques associated with ovarian stimulation probably due to low levels of LH in the middle and in the late luteal phase. This defect seems to be associated with supraphysiological steroid levels at the end of follicular phase. The luteal phase insufficiency has not got a diagnostic test which has proven reliable in a clinical setting. Luteal phase after ovarian stimulation becomes shorter and insufficient, resulting in lower pregnancy rates. Luteal phase support with progesterone or hCG improves pregnancy outcomes and no differences are found among different routes of administration. However, hCG increases the risk of ovarian hyperstimulation syndrome. In relation to the length of luteal support, the day of starting it remains controversial and it does not seem necessary to continue once a pregnancy has been established. After GnRHa triggering ovulation, intensive luteal support or hCG bolus can overcome the defect in luteal phase, but more studies are needed to show the LH utility as support.

Ovarian hyperstimulation syndrome (OHSS) is the most serious iatrogenic complication associated with ovarian stimulation. It is only in recent years that the understanding of OHSS has advanced sufficiently to develop treatment options aimed at reducing the incidence and effects of OHSS. Currently, there is no good test or method for identifying susceptible patients. Nevertheless, progress has been made in the prevention of OHSS. Physicians have a wide range of treatment options, including coasting, re-initiation of a GnRH antagonist, and application of agonists, like dopamine in the luteal phase or triggering oocyte maturation with a bolus of GnRH agonist. These treatments, together with other procedures, like oocyte/embryo vitrification, have allowed physicians to improve the prediction and prevention of OHSS.

Data concerning the effects of increased body mass index (BMI) on ovarian and pregnancy outcome are rich, but the results are rather controversial. Regarding pharmacogenetics, gene polymorphisms of hormonal receptor genes, such as Estrogen Receptor alpha (ESR1), Estrogen Receptor beta (ESR2) and FSH receptor (FSHR) genes, are associated with ovarian stimulation and pregnancy outcome and may constitute a useful tool for ART experts for the prediction of this outcome. The aim of this study is to track differences in the distribution of gene polymorphisms among obese non- PCOS and non-obese patients concerning three distinct genes which are involved in the ovarian stimulation mechanism: PvuII polymorphism of ESR1 gene, RsaI polymorphism of ESR2 gene and Ser680Asn variation of FSHR gene, using restriction fragment length polymorphism analysis and real-time polymerase chain reaction. A total of 151 normally ovulating female patients underwent IVF or ICSI. Interestingly, the pregnancy rate in the BMI≥30 kg/m2 group was higher in a statistically significant way (40.9% versus 17.8%, p=0.023). The obese patients of this study were in need of increased total FSH dose in order to achieve a satisfactory oocyte number (p

Systemic chemotherapy frequently causes primary ovarian insufficiency. In prepubertal girls, currently the only option to preserve ovarian function is ovarian tissue preservation. The use of gonadotropin-releasing hormone analogues given in combination with chemotherapy has been studied in reproductive age women. The exact mechanism is unknown, but some of the proposed protective mechanisms could theoretically protect the prepubertal ovary as it has been theorized in many of the studies on reproductive age women. None of the studies implies an adverse affect of GnRH analogue administration in terms of worsening health or cancer status. As 83% of children diagnosed with cancer will survive into adulthood, GnRH analogue administration to female childhood cancer patients in combination with chemotherapy might represent a valuable attempt to preserve future ovarian function and fertility when ovarian tissue preservation is not an option.

With the development of modern assisted reproductive technology(ART), the treatment of infertility and the pregnant outcome by ART have been significantly improved. However, implantation failure, particularly the unexplained repeated implantation failure (RIF), is still the unsolved and principal problem to affect the outcome of ART. The completed embryo, the receptive uterus and a series of precisely controlled molecular events between the blastocyst and endometrium are all indispensable for the success of implantation. Thus, deep insight into the molecular mechanisms that impact the endometrial receptivity and embryo implantation is an effective way to improve the implantation rate. Here the novel molecular targets and biomarkers have been reviewed that are reported and proved during more recent years in the aspects of ion channels, aquaporins, long noncoding RNAs and microRNAs, kruppel like factors, metabolism related molecules and the endogenous retroviruses. Evaluation of implantation markers may help clinicians to predict pregnancy outcome and detect occult implantation deficiency. Moreover, these novel molecular targets are expected to apply to the clinical practice from bench to bedside and improve the implantation efficiency in ART and natural conception.

Molecular medical research on aromatherapy has been steadily increasing for use as an adjuvant therapy in managing psychiatric disorders and to examine its therapeutic mechanisms. Most studies, as well as clinically applied experience, have indicated that various essential oils, such as lavender, lemon and bergamot can help to relieve stress, anxiety, depression and other mood disorders. Most notably, inhalation of essential oils can communicate signals to the olfactory system and stimulate the brain to exert neurotransmitters (e.g. serotonin and dopamine) thereby further regulating mood. However, little research has been done on the molecular mechanisms underlying these effects, thus their mechanism of action remains ambiguous. Several hypotheses have been proposed regarding the therapeutic mechanism of depression. These have mainly centered on possible deficiencies in monoamines, neurotrophins, the neuroendocrine system, c-AMP, cation channels as well as neuroimmune interactions and epigenetics, however the precise mechanism or mechanisms related to depression have yet to be elucidated. In the current study, the effectiveness of aromatherapy for alleviating psychiatric disorders was examined using data collected from previously published studies and our unpublished data. A possible signaling pathway from olfactory system to the central nerve system and the associated key molecular elements of aromatherapy are also proposed.

Because of more and more accurate cardiovascular prevention programs and the increasing mean age of the general population, the use of antiplatelet treatments is progressively increasing in the last years. Moreover, the widespread use of bare-metal stents (BMS) and drug-eluting stents (DES) significantly increased the number of subjects with the need of a combined antiplatelet treatment: Aspirin (ASA) and Clopidogrel (CLO). Within the first year after coronary stenting, approximately 5% of patients needs to undergo non-cardiac surgery interventions. In such patients, current guidelines suggest to stop antiplatelet agents 7-10 days before surgery to avoid the risk of increasing blood loss. On the other hand, it has been shown that the risk of surgical bleeding, if antiplatelet drugs are continued, is lower than that of coronary thrombosis if they are withdrawn. Thus, an accurate stratification of the population according to the thrombotic risk is needed and the bleeding and the thrombotic risk should be considered in parallel. Although a growing amount of recommendations have been released by several Societies, the perioperative handling of antiplatelet drugs still represents a major concern in clinical practice. In this review we report the major literature data about the perioperative handling of antiplatelet drugs. Moreover, in order to describe future treatment perspectives and to identify valuable alternatives to current antiplatelet agents in the perioperative period, pharmacokinetic and pharmacodynamic characteristics of newer antiplatelet drugs are reported and analyzed.

Overexpression of the human epidermal growth factor receptor 2 (HER2) is identified in approximately 25- 30% of breast cancers and indicates a poor prognosis. Trastuzumab, the anti-HER2 monoclonal antibody (mAb), has shown significant clinical effects selectively in HER2-overexpressing metastatic breast cancer (MBC) with improved overall survival and reduced recurrent risk. However, there is an urgent need to develop new strategies to overcome innate and acquired trastuzumab resistance, which has increasingly occurred. Recently, an increased understanding of mechanisms of trastuzumab resistance significantly promotes the development of novel targeted therapies for trastuzumabrefractory disease. It is believed that aberrant activations of several signaling pathways involving the human epidermal growth factor receptor (EGFR/HER) family, phosphoinositide 3 kinase/Akt (PI3K/Akt) pathway, and vascular endothelial growth factor (VEGF) family, contribute to the development of trastuzumab resistance. Novel agents that target these relevant signal pathways provide some potential solutions, such as tyrosine kinase inhibitors (TKIs) and mAbs. HER2 is also recognized as an immunotherapeutic target. The failure to induce immune-mediated antitumor response is another important reason for trastuzumab resistance. Strategies to boost T cell-mediated immune responses specific to HER2 including HER2 vaccines and bispecific antibodies (bsAbs) could be developed as a promising way to prevent relapse or combat trastuzumab resistance. In this review, the emerging data from preclinical and clinical studies related to these novel therapies will be discussed.

Currently, schizophrenia, as a serious psychiatric disorder, continues affecting the quality of life in the psychotics. This disease is often debilitating and chronic, showing broad symptoms at one end by hallucinations, delusions, thought disorder and the other end by affective flattening, catatonia, social isolation. In order to combat this disease, many antipsychotic drugs have been developed and introduced into clinical practice in the past half century. However, only a small minority of them can treat effectively schizophrenia without side effects. In view of this situation, high attention has been given to the exploration of desired antipsychotic agents influential especially through the modulation of dopamine and serotonin receptors with substantial strides made in recent years, leading to the discovery of many novel chemical entities with intriguing profiles. In this review, we summarize novel structural antipsychotics in development and discuss the future direction of ideal antipsychotic drug candiates. In particular, the promising atypical antipsychotic profiles of new molecules and the inspirations for their design are highlighted.

Constant oxygen supply is essential for proper tissue development, homeostasis and function of all eukaryotic organisms. Cellular response to reduced oxygen levels is mediated by the transcriptional regulator hypoxia-inducible factor- 1 (HIF-1). It is a heterodimeric complex protein consisting of an oxygen dependent subunit (HIF-1α) and a constitutively expressed nuclear subunit (HIF-1β). In normoxic conditions, de novo synthesized cytoplasmic HIF-1α is degraded by 26S proteasome. Under hypoxic conditions, HIF-1α is stabilized, binds with HIF-1β and activates transcription of various target genes. These genes play a key role in regulating angiogenesis, cell survival, proliferation, chemotherapy, radiation resistance, invasion, metastasis, genetic instability, immortalization, immune evasion, metabolism and stem cell maintenance. This review highlights the importance of hypoxia signaling in development and progression of various vision threatening pathologies such as diabetic retinopathy, retinopathy of prematurity, age-related macular degeneration and glaucoma. Further, various inhibitors of HIF-1 pathway that may have a viable potential in the treatment of oxygendependent ocular diseases are also discussed.