Preparation and In-vitro Evaluation of Gastroretentive Bupropion Hydrochloride Tablets

Purpose: To develop a gastroretentive formulation of bupropion hydrochloride in the form of floating tablets.Methods: Floating tablets were prepared by wet granulation method using various amounts of sodium carboxymethycellulose (NaCMC), different molecular weight grade of hydroxypropyl methylcellulose (HPMC) and varying amounts of fillers (microcrystalline cellulose, lactose and tricalcium phosphate). Sodium bicarbonate was also incorporated as the gas-generating agent. The formulations were tested for their physical properties, floating lag time, duration of floating and in-vitro drug release.Results: All the tablet formulations containing either HPMC K4M or HPMC K15M as the sustained release polymer together with either microcrystalline cellulose (MCC) or lactose, floated in the release medium for > 10 h. Tablets prepared with MCC released ≥ 79 % of the drug after 10 h, while those prepared with lactose released ≥ 85 % of the drug within the same period. Tablets containing NaCMC alone did not show good floating properties but when HPMC K4M was also incorporated at certain ratios, tablets with good floating behavior and suitable drug release patterns were produced. Drug release kinetic studies showed that formulations fitted best to the Higuchi model.Conclusion: The developed floating tablets of bupropion HCl exhibited prolonged drug release for ≥ 10 h, and, thus may improve bioavailability and minimize fluctuations in plasma drug concentration

Influence of hyaluronan on endometrial receptivity and embryo attachment in sheep

An increasing number of reports suggests a role of hyaluronan (HA) in female reproduction and interest in its application in assisted reproduction is rising. However, there are contrasting data about the effectiveness of adding HA to the embryo-transfer medium on improving pregnancy rates. Using sheep as an experimental model, the studies reported here analysed the impact of HA infusion into the uterus on embryo attachment to uterine luminal epithelium (LE) and expression of selected markers of uterine receptivity. On Day 14 after natural mating (pre-attachment), uterine horns were infused with either (n = 4 each): PBS (control), HA (1 mg mL–1), HA + hyaluronidase 2 (Hyal2; 300 IU mL–1) or 4-methyl-umbelliferone (HA-synthesis inhibitor; 4MU, 1 mM). HA immunostaining on uterine sections collected on Day 17 was negative in the 4MU group and weak in the HA+Hyal2 group. In contrast to 4MU, which resulted in 100% attachment, HA infusion blocked embryo attachment in all treated animals. This was accompanied by the disappearance of mucin 1 and increased expression of osteopontin and CD44v6 in the LE of uteri with attached embryos. In conclusion, the presence of HA at the embryo–maternal interface during embryo implantation resulted in reduced endometrial receptivity and inhibited the interaction of trophoblasts with the LE, whereas clearance of HA favoured embryo attachment

Global Transcriptomic Profiling of Bovine Endometrial Immune Response In Vitro. I. Effect of Lipopolysaccharide on Innate Immunity

The dysregulation of endometrial immune response to bacterial lipopolysaccharide (LPS) has been implicated in uterine disease and infertility in the postpartum dairy cow, although the mechanisms are not clear. Here, we investigated whole-transcriptomic gene expression in primary cultures of mixed bovine epithelial and stromal endometrial cells. Cultures were exposed to LPS for 6 h, and cellular response was measured by bovine microarray. Approximately 30% of the 1006 genes altered by LPS were classified as being involved in immune response. Cytokines and chemokines (IL1A, CX3CL1, CXCL2, and CCL5), interferon (IFN)-stimulated genes (RSAD2, MX2, OAS1, ISG15, and BST2), and the acute phase molecule SAA3 were the most up-regulated genes. Ingenuity Pathway Analysis identified up-regulation of many inflammatory cytokines and chemokines, which function to attract immune cells to the endometrium, together with vascular adhesion molecules and matrix metalloproteinases, which can facilitate immune cell migration from the tissue toward the uterine lumen. Increased expression of many IFN-signaling genes, immunoproteasomes, guanylate-binding proteins, and genes involved in the intracellular recognition of pathogens suggests important roles for these molecules in the innate defense against bacterial infections. Our findings confirmed the important role of endometrial cells in uterine innate immunity, whereas the global approach used identified several novel immune response pathways triggered by LPS in the endometrium. Additionally, many genes involved in endometrial response to the conceptus in early pregnancy were also altered by LPS, suggesting one mechanism whereby an ongoing response to infection may interfere with the establishment of pregnancy

Filter-Based Fading Channel Modeling

A channel simulator is an essential component in the development and accurate performance evaluation of wireless systems. A key technique for producing statistically accurate fading variates is to shape the flat spectrum of Gaussian variates using digital filters. This paper addresses various challenges when designing real and complex spectrum shaping filters with quantized coefficients for efficient realization of both isotropic and nonisotropic fading channels. An iterative algorithm for designing stable complex infinite impulse response (IIR) filters with fixed-point coefficients is presented. The performance of the proposed filter design algorithm is verified with 16-bit fixed-point simulations of two example fading filters

Global Transcriptomic Profiling of Bovine Endometrial Immune Response In Vitro. II. Effect of Bovine Viral Diarrhea Virus on the Endometrial Response to Lipopolysaccharide

Infection with noncytopathic bovine viral diarrhea virus (ncpBVDV) is associated with uterine disease and infertility. This study investigated the influence of ncpBVDV on immune functions of the bovine endometrium by testing the response to bacterial lipopolysaccharide (LPS). Primary cultures of mixed epithelial and stromal cells were divided into four treatment groups (control [CONT], BVDV, CONT+LPS, and BVDV+LPS) and infected with ncpBVDV for 4 days followed by treatment with LPS for 6 h. Whole-transcriptomic gene expression was measured followed by Ingenuity Pathway Analysis. Differential expression of 184 genes was found between CONT and BVDV treatments, showing interplay between induction and inhibition of responses. Up-regulation of TLR3, complement, and chemotactic and TRIM factors by ncpBVDV all suggested an ongoing immune response to viral infection. Down-regulation of inflammatory cytokines, chemokines, CXCR4, and serine proteinase inhibitors suggested mechanisms by which ncpBVDV may simultaneously counter the host response. Comparison between BVDV+LPS and CONT+LPS treatments showed 218 differentially expressed genes. Canonical pathway analysis identified the key importance of interferon signaling. Top down-regulated genes were RSAD2, ISG15, BST2, MX2, OAS1, USP18, IFIT3, IFI27, SAMD9, IFIT1, and DDX58, whereas TRIM56, C3, and OLFML1 were most up-regulated. Many of these genes are also regulated by IFNT during maternal recognition of pregnancy. Many innate immune genes that typically respond to LPS were inhibited by ncpBVDV, including those involved in pathogen recognition, inflammation, interferon response, chemokines, tissue remodeling, cell migration, and cell death/survival. Infection with ncpBVDV can thus compromise immune function and pregnancy recognition, thereby potentially predisposing infected cows to postpartum bacterial endometritis and reduced fertility

Polyunsaturated fatty acids influence offspring sex ratio in cows

Dietary polyunsaturated fatty acids (PUFAs) can influence fertility in farm animals. Some evidence in mice and sheep have suggested that PUFAs may influence offspring sex ratio, which may have significant value for cattle production. To test this hypothesis, three groups of Holstein cows were supplemented with either 0%, 3% or 5% protected fat (PF) in the form of calcium salt of fatty acids (rich in omega-6) from 14–21 days pre-partum until conception. Proven-fertile frozen semen from the same ejaculate was used for insemination. Calf sex recorded at birth was 8/19 (42.1%) male offspring in the control group, increasing to 14/20 (70%, P > 0.05) and 17/20 (85%, P < 0.05) in 3% and 5% PF, respectively. To test if this effect was caused by a direct influence on the oocyte, we supplemented bovine cumulus oocyte complexes during in vitro maturation with either omega-3 alpha-linolenic acid (ALA), omega-6 linoleic acid (LA) or trans-10, cis-12 conjugated linoleic acid (CLA). Sex ratio of the produced transferable embryos was determined using PCR of SRY gene. Similar to the in vivo results, sex ratio was skewed to the male side in the embryos derived from LA- and CLA-treated oocytes (79% and 71%) compared to control and ALA-treated oocytes (44% and 54%, respectively). These results indicate that both dietary and in vitro supplementation of omega-6 PUFAs can skew the sex ratio towards the male side in cattle. Further experiments are required to confirm this effect on a larger scale and to study the mechanisms of action that might be involved

Bovine Endometrial Cells Mount Innate Immune Response to the Intracellular Ligands CL097 and Poly(dA:dT) Indicating Roles against Uterine Viruses

Uterine infection and endometritis cause infertility and economic losses in the cattle industry. The innate immune response of the endometrium is critical in the elimination of pathogenic organisms that invade the uterus in postpartum cows. This study investigated the response of bovine endometrium to synthetic intracellular ligands which activate innate immunity by stimulating similar receptors to those used to recognise the presence of some viruses. Mixed primary epithelial and stromal cell cultures were treated with 5 μg/ml of CL097 (a TLR7/8 ligand) or 2 μg/ml of poly(dA:dT) (a DNA analogue) for either 6 h or 24 h. Cellular responses were assessed by the mRNA expression of 18 immune-related genes and 3 endogenous reference genes by conventional PCR followed by qRT-PCR from four replicate experiments. Bovine endometrial cells expressed the cytosolic pattern recognition receptors (PRRs) DDX58 (RIG-I), IFIH1 (MDA5) and LRRFIP1 which act as intracellular nucleic acid sensors. Neither ligand altered the expression of the extra-cytosolic pattern recognition receptors (PRRs) TLR3, TLR4, TLR7 or TLR8 whereas poly(dA:dT) treatment increased the expression of IFIH1 and DDX58. Treated cells also responded to CL097 or poly(dA:dT) with a differential up-regulation of genes involved in innate immune response including type I interferon/antiviral response (MX1, IFNAR1), antimicrobial activity (MUC1, SLPI) and cytokine activity (TNF, IL1B, IL8). Bovine endometrial cells therefore express both cytosolic and extra-cytosolic intracellular PRRs and are able to mount an innate immune response upon stimulation with intracellular ligands. This suggests an important role for these cells in the defence against viruses that may be present in the uterus in postpartum cows

A molecular biology and phase II trial of lapatinib in children with refractory CNS malignancies: a pediatric brain tumor consortium study.

High expression of ERBB2 has been reported in medulloblastoma and ependymoma; EGFR is amplified and over-expressed in brainstem glioma suggesting these proteins as potential therapeutic targets. We conducted a molecular biology (MB) and phase II study to estimate inhibition of tumor ERBB signaling and sustained responses by lapatinib in children with recurrent CNS malignancies. In the MB study, patients with recurrent medulloblastoma, ependymoma, and high-grade glioma (HGG) undergoing resection were stratified and randomized to pre-resection treatment with lapatinib 900 mg/m(2) dose bid for 7-14 days or no treatment. Western blot analysis of ERBB expression and pathway activity in fresh tumor obtained at surgery estimated ERBB receptor signaling inhibition in vivo. Drug concentration was simultaneously assessed in tumor and plasma. In the phase II study, patients, stratified by histology, received lapatinib continuously, to assess sustained response. Eight patients, on the MB trial (four medulloblastomas, four ependymomas), received a median of two courses (range 1-6+). No intratumoral target inhibition by lapatinib was noted in any patient. Tumor-to-plasma ratios of lapatinib were 10-20 %. In the 34 patients (14 MB, 10 HGG, 10 ependymoma) in the phase II study, lapatinib was well-tolerated at 900 mg/m(2) dose bid. The median number of courses in the phase II trial was two (range 1-12). Seven patients (three medulloblastoma, four ependymoma) remained on therapy for at least four courses range (4-26). Lapatinib was well-tolerated in children with recurrent or CNS malignancies, but did not inhibit target in tumor and had little single agent activity.Fil: Fouladi, Maryam. St. Jude Children’s Research Hospital; Estados UnidosFil: Stewart, Clinton F.. St. Jude Children’s Research Hospital; Estados UnidosFil: Blaney, Susan M.. Baylor College of Medicine. Texas Children’s Cancer Center; Estados UnidosFil: Onar Thomas, Arzu. St. Jude Children’s Research Hospital; Estados UnidosFil: Schaiquevich, Paula Susana. St. Jude Children’s Research Hospital; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Packer, Roger J.. Children’s National Medical Center; Estados UnidosFil: Goldman, Stewart. Anne and Robert H. Lurie Children’s Hospital of Chicago; Estados UnidosFil: Geyer, J. Rusell. Children’s Hospital and Regional Medical Center; Estados UnidosFil: Gajjar, Amar. St. Jude Children’s Research Hospital; Estados UnidosFil: Kun, Larry E.. St. Jude Children’s Research Hospital; Estados UnidosFil: Boyett, James M.. St. Jude Children’s Research Hospital; Estados UnidosFil: Gilbertson, Richard J.. St. Jude Children’s Research Hospital; Estados Unido

Evaluating preclinical evidence for clinical translation in childhood brain tumours: Guidelines from the CONNECT, PNOC, and ITCC brain networks

Clinical outcomes for many childhood brain tumours remain poor, despite our increasing understanding of the underlying disease biology. Advances in molecular diagnostics have refined our ability to classify tumour types and subtypes, and efforts are underway across multiple international paediatric neuro-oncology consortia to take novel biological insights in the worst prognosis entities into innovative clinical trials. Whilst for the first time we are designing such studies on the basis of disease-specific biological data, the levels of preclincial evidence in appropriate model systems on which these trials are initiated is still widely variable. We have considered these issues between CONNECT, PNOC and ITCC-Brain, and developed a framework in which we can assess novel concepts being brought forward for possible clinical translation. Whilst not intended to be proscriptive for every possible circumstance, these criteria provide a basis for self-assessment of evidence by laboratory scientists, and a platform for discussion and rational decision-making prior to moving forward clinically