A combinatorial phage display library for the generation of specific Fab fragments recognizing human spermatozoa and inhibiting fertilizing capacity in vitro

To select a source of lymphocytes for the generation of an anti-sperm-biased combinatorial phage display library, venous blood was obtained from 34 vasovasostomy (vasectomy reversal) patients approximately 3 mo after surgery. Using a variety of immunoassays, serum was analyzed for antibodies against human spermatozoa, and a patient was selected on the basis of high titer of antibodies that recognized the equatorial region of the sperm head and inhibited sperm fertilizing capacity in vitro. Total RNA isolated from the stored lymphocytes of this individual was reversed transcribed, and gamma1 (Fd) region and kappa chains were amplified by polymerase chain reaction for the successful construction of an antibody phage display library. The library was panned against human spermatozoa to isolate sperm-specific phage that recognized the equatorial region of the sperm head. Three preparations of Fab were tested via the hamster egg penetration test. Each preparation significantly (p < 0. 005) inhibited sperm-egg binding and fusion, with one preparation (designated Fab-G) causing complete inhibition. Sequence analysis of the kappa light gene encoding Fab-G revealed a 93% homology with the light chain of human anti-human immunodeficiency virus gp120 p35 variable region. This technology may have a practical application in characterization of the immune response to spermatozoa and for the design of sperm-based contraceptive vaccines.     

昂达Windows 8平板系统及软件注册解决方案

正英特尔南下攻略的成功,也推动了低价Widnows 8平板的崛起,习惯了安卓平板电脑的亲们,在使用Windows 8平板时总容易遇到这样那样的问题,尤其是联网激活的异常,让不少购买预置正版Windows 8平板的用户大感郁闷,笔者在此特以昂达Windows 8平板为例,对Windows 8平板使用过程中遇到的系统和软件激活问题进行讲解。     

找回儿时记忆 当手柄遇到平板电脑

正小编提示针对平板电脑外接手柄应用的软件较多,在按键映射及兼容性上各有所长,除《Sixaxis Controller》外,用户也可尝试《Tincore Keymapper》、《安卓手柄助手》等软件,寻找能同自己硬件平台对接最好的软件,以获得游戏体验。     

升级要慎重 SSD硬盘接口奥秘

正体验过SSD固态硬盘的速度绝对不会想再忍受HDD机械硬盘的"龟速",面对大容量SSD固态硬盘不断刷新的最低价,有多少人能不动心?从台式机到笔记本,全方位的SSD升级势在必行。相对于看主控选SSD固态硬盘而言,如何分辨SSD固态硬盘的接口对于普通消费者而言恐怕更加实用。让我们从接口入手,一步一步了解SSD固态硬盘的奥秘吧!     

小生意也要讲科技 移动支付平台加入攻略

正超市购物、KTV包房、餐厅用餐……移动互联时代,日常消费结算的时候,完全可以通过手机直接支付。滴滴和快的这样的打车软件让不少人体验了移动支付的便利,当移动支付渐渐成为现金与信用卡之外的重要支付手段时,巨大的市场金矿形成。面对庞大的市场蛋糕,你或者你身边的人能够忍住吗?学习加入移动支付平台,在O2O、C2C、B2C的时代也做一回科技"小商贩"吧!     

Comparison of CT and MR imaging in staging of neck metastases

OBJECTIVE: To determine whether adaptive cytoprotection exists in human intestinal cells under in vitro conditions and what role, if any, endogenous prostaglandins or calcium may play in mediating this protective response. SUMMARY BACKGROUND DATA: Adaptive cytoprotection can be defined as that process whereby the administration of a low concentration of a damaging agent, termed a "mild irritant," which by itself is not injurious, can attenuate gastrointestinal mucosal injury subsequently induced by the application of higher concentrations of the same or other necrotizing agents. Despite substantial investigation, the mediator or mediators of adaptive cytoprotection remain poorly understood. METHODS: Postconfluent Caco-2 cells were used in all experiments. Cellular death was quantitated using a dual-component fluorescent assay. Changes in intracellular calcium concentration were quantitated by measuring fluorescent signal changes of the single wavelength calcium indicator (Fluo-3). Finally, prostaglandin E2 release into the media was quantitated by radioimmunoassay. RESULTS: Pretreatment of Caco-2 cells with low concentrations of ethanol (mild irritant) significantly attenuated injury induced by higher damaging concentrations of ethanol. The protection conferred by the mild irritant was directly dependent on both the concentration of the irritant used and the duration of exposure and was abrogated when cells were pretreated with an endogenous prostaglandin inhibitor (indomethacin) or if the mild irritant was administered in calcium-free media. Cells exposed to ethanol had a significant and concentration-dependent increase in intracellular calcium concentration, an effect that was highly related to cellular injury. Pretreatment with a mild irritant significantly decreased intracellular calcium increases induced by not only ethanol but also by a calcium ionophore (A23187). Cells treated with low concentrations of ethanol demonstrated no significant elevation in prostaglandin E2 release. CONCLUSIONS: Adaptive cytoprotection induced by ethanol exists in human colonocytes under in vitro conditions independent of mucosal blood flow, neural innervation, or circulating humoral factors. The authors' data suggest that this response does not require endogenous prostaglandin synthesis but may involve processes whereby intracellular calcium accumulation is prevented.     

Periodic health examination, 1996 update: 2. Screening for chlamydial infections. Canadian Task Force on the Periodic Health Examination

OBJECTIVE: To update the 1984 recommendations of the Canadian Task Force on the Periodic Health Examination on the routine screening of asymptomatic patients for infection with Chlamydia trachomatis. OPTIONS: Screening, with the use of culture or nonculture tests, of the general population, of certain high-risk groups or of all pregnant women; or no routine screening. OUTCOMES: Rates of asymptomatic and symptomatic chlamydial infection, perinatal complications, longterm complications of infection (i.e., pelvic inflammatory disease, infertility and ectopic pregnancy), coinfection with other sexually transmitted diseases, disease spread, hospital care, complications of therapy and costs of infection and of screening. EVIDENCE: Search of MEDLINE for articles published between Jan. 1, 1983, and Dec. 31, 1995, with the use of the major MeSH heading "chlamydial infections," references from recent review articles and recommendation by other organizations. VALUES: The evidence-based methods of the Canadian Task Force on the Periodic Health Examination were used. Advice from reviewers and experts and recommendations of other organizations were taken into consideration. Prevention of symptomatic disease and decreased overall costs were given high values. BENEFITS, HARMS AND COSTS: The greatest potential benefits of screening asymptomatic patients for chlamydial infections are the prevention of complications, especially infertility and perinatal complications, and the prevention of disease spread. There is no evidence that screening of the general population for chlamydial infections leads to a reduction in complications, and screening may increase costs. However, there is evidence that annual screening of selected high-risk groups and of pregnant women during the first trimester is beneficial in preventing symptoms and reducing the overall cost resulting from infection. RECOMMENDATIONS: There is fair evidence to support screening and treatment of pregnant women during the first trimester (grade B recommendation) as well as annual screening and treatment of high-risk groups (sexually active women less than 25 years of age, men or women with new or multiple sexual partners during the preceding year, women who use nonbarrier contraceptive methods and women who have symptoms of chlamydial infection: cervical friability, mucopurulent cervical discharge or intermenstrual bleeding; grade B recommendation). There is fair evidence to exclude routine screening of the general population (grade D recommendation). VALIDATION: These recommendations are similar to those of the US Preventive Services Task Force and the US Centers for Disease Control and Prevention, Atlanta. SPONSOR: These guidelines were developed and endorsed by the Canadian Task Force on the Periodic Health Examination, which is funded by Health Canada and the National Health Canada and the National Health Research and Development Program. The principal author (H.D.D.) was supported in part by the Ontario Ministry of Health and the Canadian Infectious Diseases Society Lilly Fellowship.