(E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU)

(E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU, Brivudin, Zostex, Zerpex, Zonavir), now more than 20 years after its discovery, still stands out as a highly potent and selective inhibitor of herpes simplex virus type 1 (HSV-1) and varicella-zoster virus (VZV) infections. It has been used in the topical treatment of herpetic keratitis and recurrent herpes labialis and the systemic (oral) treatment of herpes zoster (zona, shingles). The high selectivity of BVDU towards HSV-1 and VZV depends primarily on a specific phosphorylation of BVDU to its 5'-diphosphate (DP) by the virus-encoded thymidine kinase (TK). After further phosphorylation (by cellular enzymes), to the 5'-triphosphate (TP), the compound interferes as a competitive inhibitor/alternate substrate with the viral DNA polymerase. The specific phosphorylation by the HSV- and VZV-induced TK also explains the marked cytostatic activity of BVDU against tumor cells that have been transduced by the viral TK genes. This finding offers considerable potential in a combined gene therapy/chemotherapy approach for cancer. To the extent that BVDU or its analogues (i.e., BVaraU) are degraded (by thymidine phosphorylase) to (E)-5-(2-bromovinyl)uracil (BVU), they may potentiate the anticancer potency, as well as toxicity, of 5-fluorouracil. This ensues from the direct inactivating effect of BVU on dihydropyrimidine dehydrogenase, the enzyme that initiates the degradative pathway of 5-fluorouracil. The prime determinant in the unique behavior of BVDU is its (E)-5-(2-bromovinyl) substituent. Numerous BVDU analogues have been described that, when equipped with this particular pharmacophore, demonstrate an activity spectrum characteristic of BVDU, including selective anti-VZV activity.     

用碘化异丁酰硫代胆碱和2,2'-二硫联吡啶测定人血清丁酰胆碱酯酶活性

目的建立用碘化异丁酰硫代胆碱和2,2′-二硫联吡啶(2-PDS)测定人血清丁酰胆碱酯酶(EC3.1.1.8)活性的新方法。方法碘化异丁酰硫代胆碱被丁酰胆碱酯酶水解,释放出硫代胆碱,后者和2,2′-二硫联吡啶反应,产物在340nm有最大吸收峰,且吸光度的变化量与丁酰胆碱酯酶的活性成正比;并对反应条件和方法性能进行研究。结果本方法pH值选择为8.0,EPPS缓冲液为200mmol/L,底物浓度为1.0mmol/L,2-PDS为0.2mmol/L,Hill系数为1.10,Km为(6.7～6.9)×10-3mmol/L,线性为0～2000U/L。批内变异系数为0.4%～1.3%,批间为0.8%～2.7%。与碘化丁酰硫代胆碱/5,5′-双硫代-2-硝基苯甲酸方法的相关系数为0.994。结论这种方法具有较好的准确性、重复性、线性和抗干扰能力,与对照方法相比较,具有较好的相关性,可以应用于手工和全自动分析仪。     

Lipopolysaccharide induces macrophage migration via prostaglandin D(2) and prostaglandin E(2)

Lipopolysaccharide (LPS) produces prostaglandins (PGs) concomitant to eliciting macrophage migration. We evaluated the role of PGs in initiating the migration of macrophages, especially focusing on PGD(2) and PGE(2). In RAW264.7 macrophages, cyclooxygenase (COX)-2 inhibitor, CAY10404 [3-(4-methylsulphonylphenyl)-4-phenyl-5-trifluoromethylisoxazole], completely inhibited LPS-mediated migration at 4 h (early phase) but only partially inhibited the migration at 8 h (late phase), suggesting the presence of PG-dependent and -independent pathways. In the early phase, LPS up-regulated mRNA expressions of COX-2, hematopoietic PGD synthase (H-PGDS), and microsomal-PGE synthase 1, increasing PGD(2) and PGE(2) substantially. The chemoattractant receptor-homologous molecule expressed on Th2 lymphocytes (CRTH2) agonist, DK-PGD(2) (13-14-dihydro-15-keto-PGD(2)), and the EP4 agonist, ONO-AE1-329 (16-{3-methoxymethyl}phenyl-omega-tetranor-3,7-dithia-prostaglandin E(1)), but not selective agonists of D prostanoid receptor, E prostanoid receptor (EP) 2, or EP3, stimulated random migration (chemokinesis). In peritoneal macrophages from CRTH2-deficient and H-PGDS-deficient mice, LPS-mediated migration was significantly inhibited at either early or late phases of the migration. The H-PGDS inhibitor, HQL-79 [4-(diphenylmethoxy)-1-[3-(1H-tetrazol-5-yl)propyl-piperidine]], partially inhibited the migration of the RAW264.7 macrophage in both phases. These results suggest the importance of the PGD(2)/CRTH2 pathway in LPS-mediated migration of macrophages. In the late phase of migration, LPS up-regulated monocyte chemoattractant protein (MCP)-1 mRNA. The CC chemokine receptor (CCR2) antagonist, RS102895 [1'-[2-[4-(trifluoromethyl)phenyl]ethyl]-spiro[4H-3,1-benzoxazine-4,4'-piperidin]-2(1H)-one], inhibited LPS-mediated migration in the late phase without affecting the early phase. ONO-AE1-329, but not DK-PGD(2), up-regulated MCP-1 mRNA. Taken together, LPS stimulation of chemokinesis or chemotaxis, or both, occurs in macrophages via PGD(2) and PGE(2) in tandem arrangement; i.e., 1) LPS stimulates prostaglandin signaling, initiating early migration through the PGD(2)/CRTH2 and PGE(2)/EP4 signaling pathways; and 2) LPS leads induction of MCP-1, which contributes to later phase migration of the macrophages through the PGE(2)/EP4 pathway.     

血红蛋白A2和F的室间质量评价结果分析

目的 评价中国部分珠蛋白生成障碍性贫血筛查实验室检测血红蛋白A2和F的水平和现状。方法 向50家珠蛋白生成障碍性贫血实验室发放两个批号的质控品,收集实验室回报的HbA2和HbF检测值,对回报的结果按照方法分组进行统计分析,并评价其检测水平。结果 49家实验室回报了检测结果,回报率为98%。HbA2的及格率为42.9%～92.3%,HbF的及格率为27.3%～84.6%。通过稳健Z比分数统计,血红蛋白HbA2项目201311批号样本有3家实验室检测结果为不满意,201312批号样本有4家实验室检测结果为不满意,血红蛋白HbF项目201311批号样本有5家实验室检测结果为不满意,201312批号样本有3家实验室检测结果为不满意。结论 我国珠蛋白生成障碍性贫血筛查实验室检测HbA2和HbF质量有待进一步提高。     

Peginterferon-alpha(2b) and ribavirin

Hepatitis C virus infection is among the leading causes of chronic liver disease in the USA and has a worldwide prevalence of approximately 300 million people. Chronic hepatitis C virus is the most common indication for liver transplantation in the USA. Due to the chronic nature of hepatitis C virus infection, these numbers are expected to grow fourfold in the next decade. Interferon-alpha(2b) monotherapy followed by combination therapy with ribavirin have been used to treat chronic hepatitis C virus with limited success. The development of pegylated interferon-alpha(2b), (Peg-intron, Schering-Plough) instituted the next chapter in hepatitis C virus therapy. The demonstration of its safety and efficacy led to a major trial studying coadministration with ribavirin for compensated chronic hepatitis C virus infection. Pegylated interferon combination therapy has improved efficacy over standard interferon combination therapy without an increase in adverse effects. This article reviews the data regarding pegylated interferon-alpha(2b) with ribavirin therapy. The pharmacokinetics and pharmacodynamics of combination therapy will be presented along with clinical trial data. The efficacy and ease of usage of Pegintron and ribavirin support its use for chronic hepatitis C virus infection.     

Proteinase-activated receptor 2 (PAR(2)): development of a ligand-binding assay correlating with activation of PAR(2) by PAR(1)- and PAR(2)-derived peptide ligands.

A cloned rat proteinase-activated receptor (PAR)(2)-expressing cell line (KNRK-rPAR(2)) was used to study the structure-activity relationships (elevated intracellular Ca(2+)) for a series of: 1) PAR(1)-derived receptor-activating ligands (PAR(1)-APs) [SFLLR (P5), SFLLR-NH(2) (P5-NH(2)), SFLLRNP (P7), SFLLRNP-NH(2) (P7-NH(2)), and TFLLR-NH(2) (TF-NH(2))] and 2) PAR(2)-derived-activating-peptides (PAR(2)-APs) [SLIGRL-NH(2) (SL-NH(2)), SLIGR-NH(2) (GR-NH(2)), and SLIGKV-NH(2) (KV-NH(2))]. The activities of the PAR-APs were compared with the PAR(2)-AP analog trans-cinnamoyl-Leu-Ile-Gly-Arg-Leu-Orn-NH(2) tc-NH(2)), which as a [(3)H]propionyl derivative ([(3)H]propionyl-tc-NH(2)) was used to develop a radioligand-binding assay for PAR(2). The relative potencies of the PAR-APs in the Ca(2+)-signaling assay were tc-NH(2) = SL-NH(2) > KV-NH(2) congruent with P5-NH(2) > GR-NH(2) > P7-NH(2) > P7 > P5 > TF-NH(2). The reverse sequence PAR-APs, LSIGRL-NH(2) (LS-NH(2)), LRGILS-NH(2) (LR-NH(2)), FSLLRY-NH(2) (FSY-NH(2)), and FSLLR-NH(2) (FS-NH(2)), as well as the Xenopus PAR(1)-AP TFRIFD-NH(2), were inactive. The relative biological potencies of the peptides were in accord with their ability to compete for the binding of [(3)H]propionyl-tc-NH(2) (tc-NH(2) = SL-NH(2) > GR-NH(2) congruent with P5-NH(2) > P5) to KNRK-rPAR(2) cells, whereas inactive peptides (FS-NH(2); LR-NH(2)) showed no appreciable binding competition. Our data therefore validate a ligand-binding assay for the use in studies of PAR(2) and indicate that the relative biological potencies of the PAR(1)-APs for activating rat PAR(2) parallel their ability to activate human PAR(1). The relative receptor-binding activities of the PAR-APs, although in general agreement with their relative biological activities, point to differences in the intrinsic receptor-activating activities between the several PAR-APs. The binding assay we have developed should prove of use for the further study of PAR(2)-ligand interactions.     

Cataracts and cataract operations (2)

Because of the frequent occurrence of cataracts in the general population, the surgical techniques for their removal and the potential associated complications are of widespread interest. The approaches available in general and those used at the Mayo Clinic are described.     

Imaging of the atlas (C1) and axis (C2)

In imaging the atlantoaxial region in injured patients, the initial modality is plain radiography. The lateral C-spine as well as the open-mouth view are essential in this regard. On these views, it is not only important to examine the bony contour but also to look for indirect signs of injury such as prevertebral soft-tissue swelling, air in the prevertebral space, an increased width of the anterior atlantodental interval, and overriding of the C1-C2 joint on one side (the so-called wink sign of atlantoaxial rotatory subluxation). In patients in whom there is a high index of suspicion for occult trauma, but without fractures suggested or adequately visualized on routine films, or in those with severe cranial trauma, further studies should be pursued. CT scan is the modality of choice in optimally imaging the bony contours of the axis and atlas. It has limitations in visualizing transversely oriented fractures such as high dens fractures, transverse fractures of the facet joints (although widening of the facet joint is an indirect indication of facet fracture), or transverse arch fractures. Plain tomography may better demonstrate such transverse fractures but has several disadvantages. Plain tomography is often not as readily available as CT; it requires that the patient be placed in lateral decubitus position to obtain lateral tomograms, which may be contraindicated in such clinical circumstances; and it is not as easy to appreciate three-dimensional relationships on plain tomography as it is on CT. CT clearly defines the location of displaced bone fragments in relationship to the spinal canal as well as often demonstrating disc injuries. Ligamentous injury, though potentially visualized directly on MR imaging, is more commonly addressed with flexion-extension films. Flexion-extension studies should, obviously, be performed only in awake, oriented patients who are without neurologic deficit, and the studies should be done with close physician supervision and stopped at the first onset of pain. MR imaging may be helpful in demonstrating soft-tissue injuries such as hemorrhage, disc herniation, nerve root impingement, and direct spinal cord damage.     

Interleukin-2 (IL-2) immunotherapy

Various forms of immunotherapy have been employed for the treatment of cancer patients during the past 5 years, with recombinant interleukin-2 (IL-2) having been widely used in these treatment regimes. The progress of IL-2 immunotherapy is discussed.     

Pharmacological and behavioral profile of N-(4-fluorophenylmethyl)-N-(1-methylpiperidin-4-yl)-N'-(4-(2-methylpropyloxy)phenylmethyl) carbamide (2R,3R)-dihydroxybutanedioate (2:1) (ACP-103), a novel 5-hydroxytryptamine(2A) receptor inverse agonist

The in vitro and in vivo pharmacological properties of N-(4-fluorophenylmethyl)-N-(1-methylpiperidin-4-yl)-N'-(4-(2-methylpropyloxy)phenylmethyl)carbamide (2R,3R)-dihydroxybutanedioate (2:1) (ACP-103) are presented. A potent 5-hydroxytryptamine (5-HT)(2A) receptor inverse agonist ACP-103 competitively antagonized the binding of [(3)H]ketanserin to heterologously expressed human 5-HT(2A) receptors with a mean pK(i) of 9.3 in membranes and 9.70 in whole cells. ACP-103 displayed potent inverse agonist activity in the cell-based functional assay receptor selection and amplification technology (R-SAT), with a mean pIC(50) of 8.7. ACP-103 demonstrated lesser affinity (mean pK(i) of 8.80 in membranes and 8.00 in whole cells, as determined by radioligand binding) and potency as an inverse agonist (mean pIC(50) 7.1 in R-SAT) at human 5-HT(2C) receptors, and lacked affinity and functional activity at 5-HT(2B) receptors, dopamine D(2) receptors, and other human monoaminergic receptors. Behaviorally, ACP-103 attenuated head-twitch behavior (3 mg/kg p.o.), and prepulse inhibition deficits (1-10 mg/kg s.c.) induced by the 5-HT(2A) receptor agonist (+/-)-2,5-dimethoxy-4-iodoamphetamine hydrochloride in rats and reduced the hyperactivity induced in mice by the N-methyl-d-aspartate receptor noncompetitive antagonist 5H-dibenzo[a,d]cyclohepten-5,10-imine (dizocilpine maleate; MK-801) (0.1 and 0.3 mg/kg s.c.; 3 mg/kg p.o.), consistent with a 5-HT(2A) receptor mechanism of action in vivo and antipsychotic-like efficacy. ACP-103 demonstrated >42.6% oral bioavailability in rats. Thus, ACP-103 is a potent, efficacious, orally active 5-HT(2A) receptor inverse agonist with a behavioral pharmacological profile consistent with utility as an antipsychotic agent.     

Dynamic (18F)-2-fluoro-2-deoxy-D-glucose (FDG) scintigraphy of normal and tumor-bearing rats

Five normal rats, 14 rats bearing the Rous sarcoma intrarenally, and four rats with DMBA-induced mammary carcinomas were imaged by dynamic (18F)-2-fluoro-2-deoxy-D-glucose ((18F)FDG) scintigraphy and (99mTc)DTPA renography. The brain, heart, liver, kidneys, and tumor were selected as regions of interest (ROI) for time activity curves; exponential functions were fitted to the decay-corrected curves, which yielded biologic half-lives of (18F)FDG in the ROI. It was found that all organs ROI's exhibited average elimination of activity, whereas activity accumulated in the tumor ROI for the duration of the study (5 h). The (99mTc)DTPA renographies showed that the excretory function in kidneys bearing the Rous sarcoma is severely impaired. This study shows that small laboratory animals can be successfully scintigraphied with a conventional gamma camera using (18F)FDG and that the pharmacokinetics of this radiopharmaceutical may be evaluated.