Perinatal exposure of rats to Bisphenol A affects fertility of male offspring--an overview

Endocrine disruptors (ED) induce both functional and behavioral reproductive abnormalities. Bisphenol A (BPA) is a known ED that leaches from polycarbonate plastics, as such human exposure is common. Maternal BPA exposure has been shown to have negative effects on the fertility of male offspring. Pregnant rats exposed perinatally to environmentally relevant doses of BPA gave birth to offspring with significantly impaired spermatogenesis and fertility. Perinatal exposure had deleterious effects on the male germ line which manifested as impairments in the fertility of F(1) male offspring and subsequent F(2) and F(3) generations. This overview is an attempt to summarize the currently available data in the literature with regards to perinatal BPA exposure and male fertility.     

Bioorthogonal dual functionalization of self-assembling peptide fibers

The ability to modify peptide- and protein-based biomaterials selectively under mild conditions and in aqueous buffers is essential to the development of certain areas of bionanotechnology, tissue engineering and synthetic biology. Here we show that Self-Assembling peptide Fibers (SAFs) can incorporate multiple modified peptides non-covalently, stoichiometrically and without disrupting their structure or stability. The modified peptides contain groups suitable for post-assembly click reactions in water, namely azides and alkenes. Labeling of these groups is achieved using the orthogonal Cu(I)-catalyzed azide-alkyne and photoinitiated thiol-ene reactions, respectively. Functionalization is demonstrated through the conjugation of biotin followed by streptavidin-nanogold particles, or rhodamine, and visualized by electron and light microscopy, respectively. This has been shown for fibers harboring either or both of the modified peptides. Furthermore, the amounts of each modified peptide in the fibers can be varied with concomitant changes in decoration. This approach allows the design and assembly of fibers with multiple functional components, paving the way for the development of multi-component functionalized systems.     

Design, synthesis and evaluation of N-acetyl glucosamine (NAG)-PEG-doxorubicin targeted conjugates for anticancer delivery

Efficacy of anticancer drug is limited by the severe adverse effects induced by drug; therefore the crux is in designing delivery systems targeted only to cancer cells. Toward this objectives, we propose, synthesis of poly(ethylene glycol) (PEG)-doxorubicin (DOX) prodrug conjugates consisting N-acetyl glucosamine (NAG) as a targeting moiety. Multicomponent system proposed here is characterized by (1)H NMR, UV spectroscopy, and HPLC. The multicomponent system is evaluated for in vitro cellular kinetics and anticancer activity using MCF-7 and MDA-MB-231 cells. Molecular modeling study demonstrated sterically stabilized conformations of polymeric conjugates. Interestingly, PEG-DOX conjugate with NAG ligand showed significantly higher cytotoxicity compared to drug conjugate with DOX. In addition, the polymer drug conjugate with NAG and DOX showed enhanced internalization and retention effect in cancer cells, compared to free DOX. Thus, with enhanced internalization and targeting ability of PEG conjugate of NAG-DOX has implication in targeted anticancer therapy.     

Preparation of medicines for children - A hierarchy of classification

There is some confusion about the types of paediatric pharmaceutical preparation (in a regulatory and pharmaceutical development context) that are acceptable for approval by medicines regulators. Some of the confusion relates to terminology which may mean different things to different stakeholders. It may not always be possible to provide authorised, commercially manufactured, age appropriate, ready-to-administer preparations. In terms of assurance of quality and bioavailability there is a continuum from this ideal through intermediate products through authorised compounding and manipulation of commercial dosage forms to ad hoc compounding using only the skills and experience of the individual pharmacist. Additionally, it is widely known that caregivers may manipulate medicines at home, for example by segmenting tablets and by addition to foods or liquids. The first intent of the manufacturer should be to provide for children an age appropriate, ready-to-administer preparation which is commercially manufactured and approved by the competent authorities. However, there will still be a place for providing other age appropriate preparations such as approved products that are 'intermediates' requiring reconstitution before use, or instructions for compounding or manipulation of a dosage form. If compounding or manipulation is likely to be required it is preferable that data are generated by Industry, approved by the competent authorities and provided in the Summary of Product Characteristics (SmPC). It is acknowledged however, that ad hoc compounding or manipulation may also take place in certain circumstances such as logistical difficulties or to satisfy the needs of the child who does not find the authorised product to be 'age appropriate'. This paper explores compounding and manipulation of medicines in relation to approval by medicines regulators and non-approved preparation to fulfil the needs of the individual patient. Definitions are proposed to provide a hierarchical classification based on assurances of quality and bioavailability.     

Enhancement of anti-tumor immunity through local modulation of CTLA-4 and GITR by dendritic cells

Cancer vaccines have now demonstrated clinical efficacy, but immune modulatory mechanisms that prevent autoimmunity limit their effectiveness. Systemic administration of mAbs targeting the immune modulatory receptors CTLA-4 and glucocorticoid-induced TNFR-related protein (GITR) on Treg and effector T cells augments anti-tumor immunity both experimentally and clinically, but can induce life-threatening autoimmunity. We hypothesized that local delivery of anti-CTLA-4 and anti-GITR mAbs to the sites where T cells and tumor antigen-loaded DC vaccines interact would enhance the induction of anti-tumor immunity while avoiding autoimmunity. To achieve this goal, DCs transfected with mRNA encoding the H and L chains of anti-mouse CTLA-4 and GITR mAbs were co-administered with tumor antigen mRNA-transfected DCs. We observed enhanced induction of anti-tumor immunity and significantly improved survival in melanoma-bearing mice, without signs of autoimmunity. Using in vitro assays with human DCs, we demonstrated that DCs transfected with mRNA encoding a humanized anti-CTLA-4 mAb and mRNA encoding a soluble human GITR-L fusion protein enhance the induction of anti-tumor CTLs in response to DCs transfected with mRNAs encoding either melanoma or breast cancer antigens. Based on these results, this approach of using local delivery of immune modulators to enhance vaccine-induced immunity is currently being evaluated in a phase I clinical cancer immunotherapy trial.     

Evidence from gene knockout studies implicates Asc-1 as the primary transporter mediating d-serine reuptake in the mouse CNS

In the mammalian central nervous system, transporter-mediated reuptake may be critical for terminating the neurotransmitter action of D-serine at the strychnine insensitive glycine site of the NMDA receptor. The Na(+) independent amino acid transporter alanine-serine-cysteine transporter 1 (Asc-1) has been proposed to account for synaptosomal d-serine uptake by virtue of its high affinity for D-serine and widespread neuronal expression throughout the brain. Here, we sought to validate the contribution of Asc-1 to D-serine uptake in mouse brain synaptosomes using Asc-1 gene knockout (KO) mice. Total [(3)H]D-serine uptake in forebrain and cerebellar synaptosomes from Asc-1 knockout mice was reduced to 34 +/- 5% and 22 +/- 3% of that observed in wildtype (WT) mice, respectively. When the Na(+) dependent transport components were removed by omission of Na(+) ions in the assay buffer, D-serine uptake in knockout mice was reduced to 8 +/- 1% and 3 +/- 1% of that measured in wildtype mice in forebrain and cerebellum, respectively, suggesting Asc-1 plays a major role in the Na(+) independent transport of D-serine. Potency determination of D-serine uptake showed that Asc-1 mediated rapid high affinity Na(+) independent uptake with an IC(50) of 19 +/- 1 microm. The remaining uptake was mediated predominantly via a low affinity Na(+) dependent transporter with an IC(50) of 670 +/- 300 microm that we propose is the glial alanine-serine-cysteine transporter 2 (ASCT2) transporter. The results presented reveal that Asc-1 is the only high affinity D-serine transporter in the mouse CNS and is the predominant mechanism for D-serine reuptake.     

Inhibitory effect of tea polyphenols on hepatic preneoplastic foci in Wistar rats

Tea (Camellia sinensis) is one of the most widely used beverages worldwide and tea consumption has been shown to have an inverse correlation to the incidence of human cancers in epidemiological and experimental studies. In the present study, the protective effects of green tea polyphenols (GTP) and black tea polyphenols (BTP) in Wistar rats were assessed by medium-term bioassay, using altered hepatic foci (AHF) as end point. Animals were exposed to a single dose of diethylnitrosamine (DEN; 200 mg/kg body weight intraperitoneally), and GTP (1%) and BTP (1%) were then administered orally together with 0.05% 2-acetyl aminofluorene (2-AAF) crushed and mixed in the diet for 8 weeks. Numbers of AHF were scored and analyzed by quantitative stereology using the Image analysis system from frozen liver tissue sections. Tea polyphenol supplementation resulted in a significant protection against AHF induction in Wistar rats. In addition, levels of the positive biomarkers: γ-glutamyl transpeptidase and glutathione-S-transferase (placental form) were reduced with GTP and BTP supplementation. Levels of the negative biomarkers adenosine triphosphatase and glucose-6-phosphatase were also restored by GTP and BTP administration. Thus, these results show the hepatoprotective effects of GTP and BTP against DEN- and 2-AAF-induced AHF development.     

Natural history of functional gastrointestinal disorders: a 12-year longitudinal population-based study

BACKGROUND & AIMS: Functional gastrointestinal disorders (FGID) are common in the community. The natural history of FGID is unknown because of a lack of prospective population-based studies and the indistinct nature of the phenotype. We sought to report the natural history of FGID in a US population. METHODS: This prospective cohort study used data from multiple validated surveys of random samples of Olmsted County, MN, residents over a mean of a 12-year period between 1988 and 2003 (n = 1365). The surveys measured gastrointestinal symptoms experienced during the past year. Each subject received a minimum of 2 surveys. Point prevalence, onset, and disappearance rates and transition probabilities were calculated for individual FGIDs. RESULTS: Between the initial and final surveys, the point prevalences (per 100 residents) were stable for irritable bowel syndrome (8.3% and 11.4%, respectively) and functional dyspepsia (1.9% and 3.3%, respectively). The onset of each of the disorders studied was greater than the disappearance rate, but the transition probabilities varied across the different subgroups. Among people with symptoms at baseline, approximately 20% had the same symptoms, 40% had no symptoms, and 40% had different symptoms at follow-up. CONCLUSIONS: Although the prevalence of the FGID was stable over time, the turnover in symptom status was high. Many episodes of symptom disappearance were due to subjects changing symptoms rather than total symptom resolution. This transition between different FGIDs suggests a common etiopathogenesis.