Campus courtship behavior and fear of human immunodeficiency virus infection by university students

Data were collected by telephone from a random sample of 762 students at the University of Northern Colorado to examine students' fear of human immunodeficiency virus (HIV) infection and their suggested approaches to prevent the spread of the disease. Of the 762 students interviewed, 177 (24.1%) believed that HIV/acquired immunodeficiency syndrome (AIDS) was a threat to socialization on campus. Fourteen percent of the female students considered HIV/AIDS to be a threat compared with 10.1% of their male counterparts. Among all interviewees, 573 (76.7%) believed HIV/AIDS was a threat to romance at the university. Statistically significant association was found between the perceived fear of HIV/AIDS and gender. With regard to actual sexual intercourse, 86.4% of the students believed that HIV/AIDS was a major threat compared with 13.6% who did not. The association between the perception about HIV/AIDS as a threat to on-campus sexual intercourse and gender was statistically significant. Of the entire sample, 69.3% suggested abstinence as an approach to avoid HIV infection. Slightly more than 24% suggested condom use. Eighteen (10.8%) students advised that sexual contact should be only with a trusted partner. More information about HIV/AIDS should be provided to all students, especially women, in institutions of higher learning. More information can reduce the fear associated with this deadly disease.     

Characterization of an associated 16-kDa tyrosine phosphoprotein required for Ly-49D signal transduction

Ly-49D is an activating receptor on NK cells that does not become tyrosine phosphorylated upon activation. This report demonstrates that immunoprecipitation of Ly-49D, following pervanadate treatment or specific Ab cross-linking, coprecipitates a 16-kDa tyrosine-phosphorylated protein (pp16). Immunoblotting experiments and data from TCR-zeta/Fc epsilonRIgamma double knockout mice confirm that pp16 is not TCR-zeta, TCR-eta, or Fc epsilonRIgamma. Association of pp16 with Ly-49D involves a transmembrane arginine since mutation to leucine (Ly-49D[R54L]) abolishes association with pp16 in transfected P815 cells. In addition, Ly-49D(R54L) transfectants fail to mediate Ca2+ mobilization following Ab cross-linking. Therefore, signaling through Ly49D on NK cells depends on association with a distinct tyrosine phosphoprotein (pp16) in a manner analogous to that of TCR and FcR. Expression of this novel signaling peptide in both the NK and myeloid lineages indicates that pp16 is likely involved in the signal transduction cascade of additional receptor families.     

Agrobacterium tumefaciens-mediated transformation of yeast

Agrobacterium tumefaciens transfers a piece of its Ti plasmid DNA (transferred DNA or T-DNA) into plant cells during crown gall tumorigenesis. A. tumefaciens can transfer its T-DNA to a wide variety of hosts, including both dicotyledonous and monocotyledonous plants. We show that the host range of A. tumefaciens can be extended to include Saccharomyces cerevisiae. Additionally, we demonstrate that while T-DNA transfer into S. cerevisiae is very similar to T-DNA transfer into plants, the requirements are not entirely conserved. The Ti plasmid-encoded vir genes of A. tumefaciens that are required for T-DNA transfer into plants are also required for T-DNA transfer into S. cerevisiae, as is vir gene induction. However, mutations in the chromosomal virulence genes of A. tumefaciens involved in attachment to plant cells have no effect on the efficiency of T-DNA transfer into S. cerevisiae. We also demonstrate that transformation efficiency is improved 500-fold by the addition of yeast telomeric sequences within the T-DNA sequence.     

Involvement of extracellular and intracellular calcium sources in TRH-induced alpha-MSH secretion from frog melanotrope cells

The stimulatory effect of thyrotropin-releasing hormone (TRH) on alpha-melanocyte stimulating hormone (MSH) secretion from the frog pars intermedia is mediated through the phospholipase C (PLC) pathway but requires extracellular Ca2+. The aim of the present study was to investigate the respective contribution of extracellular and intracellular Ca2+ in the action of TRH on cytosolic calcium concentration ([Ca2+]i) and alpha-MSH release. In normal conditions, TRH (10(-7) M; 5 s) evoked two types of Ca2+ responses: in 63% of the cells, TRH caused a sustained and biphasic increase in [Ca2+]i while in 37% of the cells, TRH only induced a transient response. In the presence of EGTA or Ni2+, the stimulatory effect of TRH on [Ca2+]i and alpha-MSH secretion was totally suppressed. Nifedipine (10(-6) M) reduced by approximately 50% the amplitude of the two types of Ca2+ responses whereas omega-conotoxin GVIA (10(-7) M) suppressed the plateau-phase of the sustained response indicating that the activation of L-type Ca2+-channels (LCC) is required for initiation of the Ca2+ response while N-type Ca2+-channels (NCC) are involved in the second phase of the response. Paradoxically, neither nifedipine nor omega-conotoxin GVIA had any effect on TRH-induced alpha-MSH secretion. The PLC inhibitor U-73122 (10(-6) M) significantly reduced the transient increase in [Ca2+]i and totally suppressed the sustained phase of the Ca2+ response but had no effect on TRH-induced alpha-MSH secretion. The stimulatory effect of TRH on PLC activity was not effected by nifedipine and omega-conotoxin GVIA but was abolished in Ca2+-free medium. Ryanodine had no effect on the TRH-induced stimulation of [Ca2+]i and alpha-MSH secretion. Concomitant administration of nifedipine/omega-conotoxin GVIA or U-73122/omega-conotoxin GVIA markedly reduced the response to TRH but did not affect TRH-evoked alpha-MSH release. In contrast, concomitant administration of U-73122 and nifedipine significantly reduced the effect of TRH on both [Ca2+]i and alpha-MSH release. Taken together, these data indicate that, in melanotrope cells, activation of TRH receptors induces an initial Ca2+ influx through nifedipine- and omega-conotoxin-insensitive, Ni2+-sensitive Ca2+-channels which subsequently activates LCC and causes Ca2+ mobilization from intracellular pools by enhancing PLC activity. Activation of the PLC causes Ca2+ entry through NCC which is responsible for the plateau-phase of sustained Ca2+ response. Although nifedipine and U-73122, separately used, were devoid of effect on secretory response, Ca2+ entry through LCC and mobilization of intracellular Ca2+ are both involved in TRH-evoked alpha-MSH release because only one source of Ca2+ is sufficient for inducing maximal hormone release. In contrast, the Ca2+ influx through NCC does not contribute to TRH-induced alpha-MSH secretion.     

Treatment of experimental Staphylococcus epidermidis endophthalmitis with oral trovafloxacin

In this report, a replication-defective herpes simplex virus type 1 (HSV-1) vector has been employed to deliver the Escherichia coli LacZ and HSV thymidine kinase (HSVtk) genes to six human ovarian carcinoma cell lines and the efficacy of gene transfer compared to that of adenoviral vectors in vitro. The transduction efficiency of the LacZ-containing virus TOZ.1 was evaluated qualitatively and quantitatively following infection of the different ovarian cancer cell lines. The therapeutic ability of the HSV-T3 vector, which contains the HSVtk gene, was additionally investigated in comparison to the AdCMVHSVTK. Our results show that HSV-1-mediated gene transfer is quantitatively superior to adenoviral vector in five of the six ovarian cancer cell lines at a 100-fold lower dose in vitro. Our preliminary studies suggest that HSV-1 may be a promising alternative vector for ovarian cancer gene therapy.     

Acute traumatic cardiac tamponade treated solely by percutaneous pericardial drainage

The author suggests that anxiety disorders are related to a deficiency in the endogenous opioid system. The author classifies deficiencies of the endogenous opioid system as congenital or acquired, and also as real or relative. Individuals with 'real deficiency' cannot function adequately in any situations, including situations which are natural for human beings. Persons with 'relative deficiency' are unable to function adequately under circumstances which are unnatural for humans: their 'adaptational reserve' is insufficient. The use of opioid substances and alcohol is a form of self-medication to reduce anxiety. Acupuncture and its variations, psychotherapy, and the administration of placebo can decrease anxiety because these therapeutic maneuvers activate the endogenous opioid system.     

Reversal of cerebral vasospasm using an intrathecally administered nitric oxide donor

A systematic approach to evaluation of suspected occupational lung disorders is presented to assist the health care professional with diagnosis, treatment, and prognosis, as well as management of the disease in the workplace.