Simultaneous confirmation and differentiation of human T-lymphotropic virus types I and II infection by modified western blot containing recombinant envelope glycoproteins

A modified Western blot (WB) that includes both shared (r21e) and unique recombinant envelope proteins from human T-lymphotropic virus (HTLV) type I (rgp46I) and type II (rgp46II) was compared to conventional HTLV serologic tests in 379 United States blood donors and individuals residing in diverse geographic regions, and the specimens were categorized as positive (n = 158), indeterminate (n = 158), or negative (n = 63) for HTLV infection. Of the 158 HTLV-I/II-positive specimens (66 requiring radioimmunoprecipitation assay [RIPA] for confirmation), 156 reacted concordantly with r21e, gag, and either rgp46I or rgp46II, thus eliminating the need for RIPA in all but two specimens and yielding a test sensitivity of 98.7 percent. Of the 158 indeterminate and 63 negative specimens, none reacted with r21e and rgp46I or rgp46II, yielding a test specificity of 100 percent. Furthermore, analysis of an additional 184 consecutive specimens from a retrovirology reference laboratory demonstrated that the modified WB correctly identified 27 of 28 HTLV-I specimens and all 13 HTLV-II specimens, with a test sensitivity of 97.6 percent. None of specimens that were indeterminate or nonreactive in conventional WB and/or RIPA and none of the screening enzyme immunoassay-negative specimens reacted with r21e and either rgp46I or rgp46II, for a test specificity of 100 percent. Thus, the modified WB appears to be highly sensitive and specific for simultaneous detection and discrimination of HTLV-I from HTLV-II and has the advantage of being a one-step assay that is easily performed in all types of laboratory settings and allows rapid, reliable, and standardized testing for HTLV-I/II infection.     

Isolation of an abnormal protein C molecule from the plasma of a patient with thrombotic diathesis

Protein C has been purified from the plasma of a patient with thrombotic diathesis. Both before and after isolation, the protein showed reduced capacity to hydrolyze synthetic substrates and to anticoagulate plasma. Proteolysis with the soluble thrombin- thrombomodulin complex proceeded normally and to completion as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. Approximately one-third of the protein is functional, indicating a heterozygous defect. Indirect studies suggest that the abnormal component can bind to protein S and phospholipids. Both forms of activated protein C can also incorporate radiolabeled diisopropylfluorophosphate.     

Oxytocin receptors and parturition. I. Control of oxytocin receptor concentration in the rat myometrium at term

Rat myometrium exhibited a marked rise in the concentration of oxytocin (OT) receptors during parturition. The elevation began several hours before labor, was maximal during labor, and declined several hours later. In the perinatal period, the change in OT receptor concentration was proportional to the ratio of plasma estradiol to progesterone levels. Several hours before the increase in OT receptor concentration, there was a proportional increase in estrogen receptor concentration in both the cytosol and nuclear fractions of the myometrium. In view of the known action of estrogens in increasing the concentration of OT receptors in rat uterus, we propose that the following sequence of events occurs in the initiation of labor in the rat. The decline in serum progesterone permits estradiol to stimulate the synthesis of estrogen receptors in the myometrium. This increased concentration of estrogen receptors and their occupancy by estradiol stimulates the appearance of more OT receptors, which then trigger labor by interacting with circulating OT.     

Localization of pancreatic insulinoma: comparison of pre- and intraoperative US with CT and angiography

Methods of preoperative radiologic localization of insulinoma were compared in 52 patients, 44 of whom had solitary tumors. Examinations performed in these 44 patients were preoperative ultrasonography (US) in 28, angiography in 26, and computed tomography in 23. Prospective sensitivities were 61%, 54%, and 30%, respectively. Imaging sensitivities were lower for the eight patients with multiple insulinomas. In 28 of the 44 patients, intraoperative US was performed without the examiner being aware of the surgical findings. The sensitivity was 84%. Four insulinomas were not palpable but were visualized sonographically. The combined sensitivity of intraoperative US and surgical palpation for detecting solitary insulinomas was 100%. High-frequency intraoperative US is valuable for detecting occult solitary insulinomas and considerably useful for determining the proximity of insulinomas to the pancreatic and bile ducts.     

贴壁培养细胞胶体金免疫电镜标本制备技术的改进

介绍一种贴壁培养细胞胶体金免疫电镜标本制备方法,本法适用于观察各种因素对细胞表面抗原性质影响的免疫电镜研究。