Interleukin 1-induced lymphocyte binding to endothelial cells. Role of cAMP as a second messenger

Interleukin 1 (IL 1) is a potent protein mediator of inflammation. Among other things it increases the number of lymphocytes adhering to endothelial cell monolayers. We analyzed the signal transduction during IL 1-induced lymphocyte binding. Dibutyryl cyclic AMP, which is a cAMP analog able to penetrate into the cytosol, increased lymphocyte binding to the same extent as IL 1. Direct activation of adenylate cyclase by forskolin enhanced also lymphocyte binding. IL 1 increased the level of cytosolic cAMP in a time- and dose-dependent manner measured with radioimmunoassay. 2',5'-Dideoxyadenosine, which is an inhibitor of adenylate cyclase, decreased both the IL 1-induced lymphocyte binding to endothelial cells and elevation in cytosolic cAMP levels. Lymphocyte binding increased with cytosolic cAMP levels in accordance with elevation of IL 1 concentration. These results suggest that cAMP is essential in signal transduction during IL 1-induced lymphocyte binding to cultured endothelial cell monolayers.     

Properties of B cells and Thy-1-antigen-expressing cells infiltrating rat renal allografts

We have examined (1) the frequency of B cells secreting antibodies against donor major histocompatibility complex (MHC) antigens and (2) the properties of Thy-1-antigen-expressing leukocytes in rats rejecting renal allografts. Our results show that B cells secreting antibodies are present in the inflammatory cell population at the frequency of 1:850. Among them only 1 out of 2-150 is engaged in production of antibodies directed to the graft MHC antigens, depending on the method of assay. This suggests that despite the observed significant production of nonspecific immunoglobulin in situ, only a minority of the B-cell population is specifically committed to the graft MHC antigens. This finding is concordant with the described previously low frequencies of the T cells specifically directed toward the graft MHC antigen. The role of the "immunologically noncommitted" cells in graft rejection is unknown. We have found that a substantial part (up to 60%) of inflammatory cells invading a rat kidney allograft express the Thy-1 antigen. This suggests that they might be immature (progenitor?) cells and, therefore, unable to respond to the graft antigens. Progenitor-like properties of these cells have been confirmed by their ability to reconstitute lethally irradiated syngeneic rat. Finally, these immature cells are of lymphoid, not of myeloid, linkage, because they do not proliferate in the presence of GM-CSF.     

Association between report of insomnia and daytime functioning

ObjectivesThe relationship between reports of insomnia and daytime functioning was investigated using hierarchical regression. The presence or absence of a report of insomnia was the predictor of primary interest. A number of covariates were included in the model: demographic variables, health variables, and quantitative sleep parameters.MethodsData were collected from a community sample in the Memphis, Tennessee area. Data from 734 volunteers, ranging in age from 20 to 96 years were analyzed. The sample included 235 individuals who reported having chronic insomnia and 499 individuals who reported no sleep problems. Participants completed a 2-week sleep diary, a battery of daytime functioning questionnaires, and a medical disorders checklist. Demographic information was also collected. The daytime functioning assessment included the Beck Depression Inventory, the State-Trait Anxiety Inventory, the Epworth Sleepiness Scale, the Insomnia Impact Scale, and the Fatigue Severity Scale. The hierarchical regression model included four sets. The first three sets consisted of 18 variables capturing demographic, health, and sleep diary parameters. The fourth set included a single dichotomous variable representing the presence or absence of a report of insomnia.ResultsReports of insomnia were a significant predictor of all five daytime functioning measures, which is consistent with previous research. We also showed that reports of insomnia were able to uniquely explain a significant amount of variability in self-reported daytime functioning after controlling for demographics, health, and sleep diary variables. The pattern of individual variables that reached significance in the first three sets varied depending on which daytime functioning measure was predicted, however, age, the presence of pain, the presence of mental health problems, SOL, and WASO were the most commonly significant predictors of poor daytime functioning from these sets across measures.ConclusionsIndividuals’ perceptions of their sleep are related to differences in their reported daytime functioning, which are not accounted for by demographic factors, health surveys, or quantitative sleep assessments. Reports of insomnia may be related to a set of common cognitive factors among individuals who report having insomnia which cause them to be distressed with their sleep and increase their dissatisfaction with daytime functioning. Relevance of the findings to insomnia research and clinical management are discussed.     

Effectiveness of treating peripapillary geographic choriopathy

The results of treatment of 77 patients (127 eyes) with peripapillary geographic choriopathy (PGC) were generalized. The drug therapy gave positive results in 45.4% of cases, relative stabilization was noted in 54.6% of cases. In patients with stages I-II PGC in comparison with stage III the efficacy of treatment was significantly higher. Improvement in the exudative phase of PGC was achieved 2.6 times frequently than in the cicatricial phase. In the patients who received 2-3 courses of therapy annually the likelihood of persistence of the stabilization of the disease is 91.2%, while without treatment it descends to 29.7%. In argon laser coagulation (ALC) the positive result was obtained in 17 out of 26 eyes and retained more than 2 years in 15 out of 23 eyes. After choreoid revascularization (CR) in patients with stages II-III PGC (with visual that in those untreated functions disorders) improvement continued for 17(10 months in all 6 eyes. Operative treatment of retinal detachment in patients with PGC is effective. The findings suggest the higher likelihood of persistence of stabilization in cases of treatment in patients treatment.     

Chronic rejection of rat aortic allografts: effect of inhibition of the thromboxane cascade

Non-immunosuppressed rat aortic allografts from DA (RT1^av1) to WF (RT1^u) strain develop, after a short reversible acute rejection episode, chronic arteriosclerotic changes in the vascular wall, which are indistinguishable from those seen in human allografts during chronic rejection [1]. Incubation of the aortic wall segments in vitro and immunochemical assays demonstrated that the allografts synthesized increased amounts of TxB2, but not 6-keto-PGF_1α or LTB4, compared to syngenic or normal aortas. The two major cellular components of the vascular wall, intima and adventitia, were incubated separately after microdissection. TxB2 was produced in the adventitia, whereas most of the 6-keto-PGF₁α was synthesized in the intima. Administration of a specific TxA2 receptor inhibitor to the recipient rat reduced significantly the proliferation of adventitial inflammatory cells and the intimal smooth muscle cells. Nevertheless, it only delayed but did not inhibit the overall sclerosis of the intima.     

Experimental Setup for Studying Wireless Energy Transfer using Magnetic Coupling in Auxiliary Circulation Systems

An experimental setup for research into wireless energy transfer using magnetic coupling is suggested. The results of the experimental research of wireless energy transfer using magnetic coupling within the range 60–190 kHz are presented. It is demonstrated that the efficiency of energy transfer using magnetic coupling is at the level of 20%.