Incidence and clinical significance of false-negative sextant prostate biopsies

PURPOSE: Since most patients do not undergo repeat sextant prostate biopsies after a biopsy is positive for prostate cancer, the true incidence of false-negative biopsies is not well defined. We assess the incidence and clinical significance of false-negative sextant prostate biopsies in patients undergoing radical prostatectomy. MATERIALS AND METHODS: A total of 118 patients with biopsy proved prostate cancer underwent repeat sextant prostate biopsy before enrollment in a prospective randomized trial of radical prostatectomy with or without neoadjuvant hormonal therapy. Clinical parameters were assessed to determine potential sources of bias. Pathological parameters and prostate specific antigen relapse-free survival rates were compared to determine the clinical significance of false-negative biopsies. RESULTS: Of the 118 patients 27 (23%) had a negative repeat sextant biopsy. Except for initial clinical stage, no differences were noted in the clinical or pathological parameters, or prostate specific antigen relapse rates in patients with negative versus positive repeat biopsies. CONCLUSIONS: Our findings suggest that this 23% incidence of false-negative biopsies represents significant cancer. This relatively high incidence is important to consider in treatment modalities in which prostate biopsy may be performed to determine response to therapy.     

Quality of life analysis of patients undergoing immunotherapy for allergic rhinitis

Allergic rhinitis has been conservatively estimated to affect 35 million Americans, with an annual US expenditure of more than $2 billion for treatment. Immunotherapy is generally administered to patients with allergic rhinitis when avoidance is impossible or impractical, when pharmacotherapy provides insufficient relief, and/or symptoms span more than one season. Immunotherapy based on quantified testing (e.g., dilutional intradermal testing [SET] or in vitro methods [RAST, ELISA]) allows administration of antigens in a manner that achieves therapeutic antigen doses more rapidly, yet more safely than immunotherapy administered through a schedule that mixes all antigens at the same concentration and advances on an empirical basis. Sixty patients who received at least one year of quantified testing-based immunotherapy were evaluated using a quality of life questionnaire and individual interviews. Changes in physical, social and emotional well-being were determined. Also investigated were changes in productivity and medication usage. The majority of patients noted significant improvement in all areas within four to six months of initiating immunotherapy, and an overwhelming majority felt that such treatment represented a worthwhile investment of their time and money.     

Problems associated with rabies preexposure prophylaxis

With the rabies vaccine presently available for preexposure prophylaxis, 20% of all individuals do not have seroconversion following routine immunizations, and 5% are allergic to this vaccine. Two experimental rabies vaccines of cell culture origin offering greater purity and potency were evaluated by means of a double-blind experiment. Thirty-one volunteers who did not have seroconversion or who were allergic to duck embryo rabies vaccine received rabies vaccine produced in either human diploid cell culture (WI-38), or hamster kidney-cell culture. All volunteers had seroconversion within 14 days of receiving a single injection of other experimental vaccine. Clinical side effects were only minor.     

Message-based priority access to local networks

Hyperchannel interfaces are designed to interface computer mainframes and peripheral equipment to a high speed bus to form a local network. Each interface executes a distributed control contention access algorithm operation revolves about fixed priorities assigned to the individual interfaces. The access algorithm is extended to provide for message-assigned priorities, to provide better bus access rights for higher classes of messages at the expense of degraded access rights for the lower classes of messages. The extension requires little additional new hardware but instead employs a replication in each interface of existing hardware.The original hyperchannel interface access mechanism is explained. The algorithm extension is described and two models are developed to assess its effect on message transmission access rights, and via these models the viability of the extended algorithm can be demonstrated quantitatively.     

Effects of fetal genotype and uterine environment on placental development in equids

Measurement of the concentrations of equine chorionic gonadotrophin (eCG) in the serum of pregnant mares and Jenny donkeys carrying normal intraspecies and hybrid interspecies pregnancies suggested that the production of this hormone may be influenced by parental gene imprinting. Specifically, a differential expression of maternal and paternal genes may control the size and secretory activity of the structures that secrete eCG, the fetal endometrial cups. However, bisection of an interspecies mule embryo followed by transfer of the resulting demi-embryos and other intact mule embryos to horse and donkey recipients resulted in striking differences in the size, secretory activity and lifespan of the endometrial cups in two types of surrogate mother. This finding has therefore demonstrated the ability of uterine factors to alter profoundly the development and characteristic phenotype of the specialized invasive chorionic girdle portion of the equine trophoblast that gives rise to the endometrial cups.     

DNA binding properties of the ecdysteroid receptor in the salivary gland of the female ixodid tick, Amblyomma hebraeum

Salivary gland degeneration in the female tick, Amblyomma hebraeum Koch (Acari: Ixodidae) is controlled by an ecdysteroid hormone. In an earlier study (Mao, H., McBlain, W.A., Kaufman, W.R., 1995. Some properties of the ecdysteroid receptor in the salivary gland of the ixodid tick, Amblyomma hebraeum. Gen. Comp. Endocrinol. 99, 340-348), we demonstrated that a protein component of a salivary gland extract binds to ponasterone A (Pon A) with high affinity (Kd-1 nM), suggesting a tick ecdysteroid receptor (EcR). In this study, the Pon A binding protein bound to calf thymus DNA; this binding could be dissociated by Drosophila hsp27 EcRE. The binding protein shifted the [32P]hsp27 EcRE band on a gel mobility shift assay; formation of the complex with hsp27 EcRE required KCl (optimal concentration was approximately 75 mM). A number of physiologically effective ecdysteroids enhanced the binding with the following order of potency: Pon A > Mur A > Mak A > 20E > ecdysone, whereas vertebrate steroids (estradiol, cholesterol, corticosterone, progesterone, testosterone) had no such effect. Using monoclonal antibodies against Drosophila EcR and USP, we found that AG 10.2 recognized three bands (90.5, 87.3 and 84 kDa for EcR) and AB11 recognized at least two major bands (50.3 and 47.1 kDa for USP) in the salivary gland extract by western blot analysis. In addition, AB11 supershifted the tick EcR-hsp27 EcRE band on a gel mobility shift assay, indicating that the tick EcR heterodimerized with a USP-like protein for DNA binding. Furthermore, selective mutations to the 15-basepair palindrome of hsp27 EcRE at positions-5, + 2, or adding a base to the spacer, resulted in considerably reduced affinity to the tick EcR/USP. We thus propose a sequence similarity of EcREs between A. hebraeum and its insect counterpart.