Analysis of ET‐A and ET‐B receptors using an isolated perfused rat lung preparation

Aims and Methods: The pulmonary and vascular effects of endothelin‐1 receptor activation were studied in isolated perfused and ventilated lung preparations from rat. The responses to endothelin‐1 (ET‐1) and the endothelin B (ET_B) receptor agonist sarafotoxin 6c (S6c) were characterized using the endothelin A (ET_A)‐receptor antagonist FR 139317, the ET_B‐receptor antagonist BQ 788 and the combined ET_A/ET_B‐receptor antagonist Bosentan. The respiratory parameter airway conductance (G_aw) and the vascular parameter perfusion flow were analysed simultaneously. Results: Concentration–response curves for ET‐1 administered intra‐arterially revealed that its most potent effect was on the vascular side while S6c had a more potent effect on airway conductance. ET‐1, given as a bolus dose intra‐arterially (100 μL of 0.2 nm ), induced a strong‐ and long‐lasting contraction of the vasculature while only a less pronounced contraction was seen in the airways. Neither of the antagonists had a significant effect per se on G_aw or perfusion flow. FR 139317 reduced the effect of ET‐1 on perfusion flow by about 50%, while airway conductance was augmented. BQ 788 enhanced the decrease in perfusion flow by ET‐1 while G_aw was not influenced. The combined ET_A/ET_B antagonist Bosentan powerfully prevented the ET‐1‐induced decrease in G_aw but did not alter its reduction in perfusion flow. Conclusions: The potent effect of ET‐1 on the vascular side of the lung is mediated mainly through ET_A receptors, whereas both ET_A and ET_B receptors are involved in G_aw in the rat lung.     

Immunoglobulin mimicry by Hepatitis C Virus envelope protein E2

Hepatitis C virus (HCV) establishes persistent infection in the majority of infected individuals. The currently accepted hypothesis of immune evasion by antigenic variation in hypervariable region 1 (HVR1) of glycoprotein E2 does not however, explain the lack of subsequent immune recognition. Here, we show that the N-terminal region of E2 is antigenically and structurally similar to human immunoglobulin (Ig) variable domains. E2 is recognized by anti-human IgG antibodies and also possesses common amino acid (aa) sequence features of the conserved v-gene framework regions of human Ig light chains in particular but also heavy chains and T cell receptors. Using a position specific scoring system, the degree of similarity of HVR1 to Ig types correlated with immune escape and persistence in humans and experimentally infected chimpanzees. We propose a unique role for threshold levels of Ig molecular mimicry in HCV biology that not only advances our concept of viral immune escape and persistent infection but also provides insight into host-dependent disease patterns.     

Does Low FEV1 in Addition to Fixed Ratio and/or Lower Limit of Normal of FEV1/FVC Improve Prediction of Mortality in COPD? The NHANES-III-linked-mortality Cohort

Purpose

There is presently an ongoing debate on the relative merits of suggested criteria for spirometric airway obstruction. This study tests the null hypothesis that no superiority exists with the use of fixed ratio (FR) of forced expiratory volume in the first second (FEV1)/forced vital capacity (FVC) < 0.7 versus less than lower limit predicted (LLN) criteria with or without FEV1 <80% predicted in regards to future mortality.

Effects of FR173657, a non-peptide B2 antagonist,on kinin-induced hypotension,visceral and peripheral oedema formation and bronchoconstriction

1. Kinins are believed to play a key role in many inflammatory conditions. Therefore, bradykinin antagonists are being developed for potential therapeutic applications. In the present investigation we describe the pharmacology, in vivo, of (E)-3-(6- acetamido- 3-pyridyl)- N-[N- [2,4- dichloro- 3-[(2- methyl-8- quinolinyl)oxymethyl]phenyl]- N-methylaminocarbonylmethyl]acrylamide ({"type":"entrez-nucleotide","attrs":{"text":"FR173657","term_id":"257935500","term_text":"FR173657"}}FR173657), a novel, non-peptide bradykinin antagonist.
2. The hypotensive effects of i.v. injections of bradykinin (50 pmol) in captopril-pre-treated anaesthetized rats were significantly inhibited by 100 nmol kg⁻¹ {"type":"entrez-nucleotide","attrs":{"text":"FR173657","term_id":"257935500","term_text":"FR173657"}}FR173657 s.c., and completely abolished by 300 nmol kg⁻¹. The full inhibitory effect developed within 60 min and remained unchanged for at least 4 h. However, the effect was reversible, since 24 h after an injection of 300 nmol kg⁻¹ {"type":"entrez-nucleotide","attrs":{"text":"FR173657","term_id":"257935500","term_text":"FR173657"}}FR173657 no inhibitory effect could be observed.
3. The plasma protein extravasation into the pancreas and duodenum induced by an i.v. infusion of bradykinin (11 nmol kg⁻¹ within 20 min) in captopril-treated anaesthetized rats was completely abolished by {"type":"entrez-nucleotide","attrs":{"text":"FR173657","term_id":"257935500","term_text":"FR173657"}}FR173657 at doses of 30 nmol kg⁻¹ s.c. and above, given 60 min before bradykinin. {"type":"entrez-nucleotide","attrs":{"text":"FR173657","term_id":"257935500","term_text":"FR173657"}}FR173657 3 nmol kg⁻¹ was ineffective, while a dose of 10 nmol kg⁻¹ produced an intermediate effect.
4. The paw oedema induced by the subplantar injection of bradykinin (30 nmol) in anaesthetized rats was inhibited slightly by s.c. injection of {"type":"entrez-nucleotide","attrs":{"text":"FR173657","term_id":"257935500","term_text":"FR173657"}}FR173657 0.3 μmol kg⁻¹, whereas 1 and 3 μmol kg⁻¹ produced significant inhibition of the bradykinin-induced oedema. The maximum inhibition amounted to about 50% and could not be increased even when the dose of {"type":"entrez-nucleotide","attrs":{"text":"FR173657","term_id":"257935500","term_text":"FR173657"}}FR173657 was increased to 30 μmol kg⁻¹. {"type":"entrez-nucleotide","attrs":{"text":"FR173657","term_id":"257935500","term_text":"FR173657"}}FR173657 did not effect the oedema caused by histamine or 5-hydroxytryptamine.
5. Bradykinin (20 nmol kg⁻¹, i.v.) caused increases in pulmonary inflation pressure by 300–600 Pa in anaesthetized, respirated guinea-pigs. The effect was reduced to 58±9% of the initial value 60 min after the s.c. injection of {"type":"entrez-nucleotide","attrs":{"text":"FR173657","term_id":"257935500","term_text":"FR173657"}}FR173657 1 μmol kg⁻¹, whereas only 9±7% remained after 10 μmol kg⁻¹. The bronchoconstrictor actions of histamine remained unaffected by {"type":"entrez-nucleotide","attrs":{"text":"FR173657","term_id":"257935500","term_text":"FR173657"}}FR173657.
6. In summary, {"type":"entrez-nucleotide","attrs":{"text":"FR173657","term_id":"257935500","term_text":"FR173657"}}FR173657 is a highly potent and selective bradykinin antagonist. The inhibitory action in vivo lasts for longer than 4 h but is fully reversible. {"type":"entrez-nucleotide","attrs":{"text":"FR173657","term_id":"257935500","term_text":"FR173657"}}FR173657, or similar compounds, will be a useful tool for the pharmacological investigation of pathophysiological states and may possess a therapeutic potential in diseases involving the endogenous release of kinins.

     

p16、Ki67及FRα预测低度宫颈上皮内瘤变转归的研究进展

宫颈上皮内瘤变(cervical intraepithelial neoplasia,CIN)已发现与宫颈癌密切相关,根据异常程度分3级CIN(CIN1,CIN2和CIN3)。约60%的CIN1可自然消退,仅有少部分发生进展。目前,迫切需要一些生物标志物作为预测因子来预测病变的转归。经检索国内外文献发现,目前大部分研究结果发现生物标志物p16、Ki67的染色结果对于CIN1的预后有预测意义,并且有部分学者研究了p16/Ki67双染结果也可以很好的预测,而目前仅少数人研究了FRα在预测CIN1转归时的意义,认为FRα可能有一定预测价值。关于这些生物标志物的预测价值,还需要其他大型的、长时间的临床随访来进一步研究它们的准确性和可靠性,也需要进行更加深入的研究去发现其他更为精准的标志物。     

The discovery and development of romidepsin for the treatment of T-cell lymphoma

Introduction: Romidepsin is a potent and selective inhibitor of histone deacetylases (HDCAi). It is also the only bicyclic inhibitor to undergo clinical assessment and is considered a promising drug for the treatment of T-cell lymphomas. The cellular action of romidepsin results in enhanced histone acetylation, as well as the acetylation of other nuclear or cytoplasmic proteins, influencing cell cycle, apoptosis, and angiogenesis. In phase II studies involving patients with relapsed or refractory of cutaneous T-cell lymphoma (CTCL) and peripheral T-cell lymphoma (PTCL), romidepsin produced overall response rates (ORR) of 34–35% and 25–38%, with complete response (CR) rates of 6% and 15–18%, respectively.

Areas covered: This review summarizes the development of romidepsin, the mechanisms behind its antineoplastic action and its pharmacology. It also covers its pharmacokinetic and pharmacodynamic properties, as well as the preclinical and clinical data on its activity in T-cell lymphoma.

Expert opinion: Since there are only few effective therapies available for T-cell lymphomas, romidepsin is a valuable option for relapsed/refractory patients with both CTCL and PTCL. It’s also generally well tolerated, and gives potentially durable responses for patients with advanced and symptomatic disease. Combinations of romidepsin with other antineoplastic agents may also further improve drug response and outcomes in T-cell lymphoma.     

On the Production of Chitosan-Coated Polycaprolactone Nanoparticles in a Confined Impinging Jet Reactor

This work is focused on the synthesis of polycaprolactone nanoparticles, coated with chitosan, in a confined impinging jet reactor using the solvent displacement method. The role of the various reacting species was investigated, evidencing that a biocompatible polymer, for example, polycaprolactone, is required to support chitosan to obtain a monomodal particle size distribution, with low particle diameters. A surfactant is required to reduce the nanoparticle size (down to a mean diameter of about 260 nm) and obtain a positive zeta potential (about +31 mV), perfectly suitable for pharmaceutical applications. Different surfactants were tested, and Poloxamer 388 appeared to be preferable to polyvinyl alcohol. The effect of the concentration of Poloxamer 388 (in the range 0.5-5 mg mL^?1) and of chitosan (in the range 1.5-5 mg mL^?1) on both the mean particle size and zeta potential was also investigated, evidencing that chitosan concentration has the strongest effect on both parameters. Finally, the effect of solvent evaporation, quenching and feed flow rate was investigated, showing that the evaporation stage does not affect particle characteristics, quenching is required to avoid particle aggregation, and a minimum liquid flow rate of 80 mL min^?1 is required in the considered reactor to minimize the particle size.     

Recent achievements in developing selective Gq inhibitors

G proteins are key mediators of G protein-coupled receptor (GPCR) signaling, facilitating a plethora of important physiological processes. The role of G proteins is much less understood than other aspects of GPCR function, which is largely due to the shortage of potent and selective G protein inhibitors. The natural cyclic depsipeptides YM-254890 and FR900359 are two of the very few known selective inhibitors of the G_q subfamily, and are used as unique pharmacological tools in the study of G _q-mediated signaling. Moreover, a peptide-based G protein antagonist-2A (GP-2A), a 27-residue peptide (27mer(I860A)) derived from phospholipase C-β3 (PLC-β3), and the small molecule BIM-46187 have also been characterized as selective G _q inhibitors within the past 5 years. In this review, we highlight the recent development in chemical syntheses, characterization, and mechanism of action of these selective G _q inhibitors. The development and application of G _q-selective inhibitors will expand our knowledge of the structure and function of G protein-mediated signaling, shed light on the development of inhibitors for other G protein classes, and feed in to drug discovery for diseases where G proteins are implicated, including various forms of cancer.     

The analysis of VH and VL genes repertoires of Fab library built from peripheral B cells of human rabies virus vaccinated donors

A human combinatorial Fab antibody library was generated from immune repertoire based on peripheral B cells of ten rabies virus vaccinated donors. The analysis of random Fab fragments from the unselected library presented some bias of V gene usage towards IGHV-genes and IGLV-gen families. The screening of the Fab library on rabies virus allowed specific human Fab antibody fragments characterized for their gene encoding sequences, binding and specificities to RV. Genetic analysis of selected Fabs indicated that the IGHV and IGLV differ from the germ-line sequence. At the level of nucleotide sequences, the IGHV and IGLV domains were found to share 74–92% and 90–96% homology with sequences encoded by the corresponding human germ-line genes respectively. IGHV domains are characterized most frequently by IGHV3 genes, and large proportions of the anti-RV heavy chain IGHV domains are obtained following a VDJ recombination process that uses IGHD3, IGHD2, IGHD1 and IGHD6 genes. IGHJ3 and IGHJ4 genes are predominantly used in RV-Fab. The IGLV domains are dominated by IGKV1, IGLV1 and IGLV3 genes. Numerous somatic hypermutations in the RV-specific IGHV are detected, but only limited amino acid replacement in most of the RV-specific IGLV particularly in those encoded by J proximal IGLV or IGKV genes are found. Furthermore, IGHV3–IGKV1, IGHV3–IGVL1, and IGHV3–IGLV3 germ-line family pairings are preferentially enriched after the screening on rabies virus.