Relationship between ambulatory blood pressure and aortic arch atherosclerosis

ObjectiveAtherosclerotic plaque in the aortic arch is an independent risk factor for ischemic stroke. Although high blood pressure (BP) measured at the doctor's office is known to be associated with aortic atherosclerosis, little is known on the association between 24-h ambulatory BP and aortic arch plaque presence and severity. Our objective was to clarify the association between ambulatory BP variables and aortic arch atherosclerosis in a community-based cohort.MethodsThe study population consisted of 795 patients (mean age 71 ± 9 years) participating in the Cardiovascular Abnormalities and Brain Lesions (CABL) study who underwent 24-h ambulatory BP monitoring (ABPM). Arch plaque was evaluated by 2D transthoracic echocardiography from a suprasternal window.ResultsAll systolic ABPM variables (24-h/daytime/nighttime mean systolic BP, daytime/nighttime systolic BP variability) were associated with the presence of any plaque and large (≥4 mm) plaque, whereas diastolic BP variables were not associated with aortic atherosclerosis. Multiple regression analysis indicated that nighttime systolic BP variability (expressed as the standard deviation of nighttime systolic BP) remained independently associated with large plaque after adjustment for age, sex, cigarette smoking, history of hypertension, diabetes mellitus, hypercholesterolemia, anti-hypertensive medication and nighttime mean systolic BP (odds ratio 1.39 per 1 standard deviation increase, 95% CI 1.00–1.93, P < 0.05).ConclusionSystolic ABPM variables are significantly associated with the presence of arch plaque. Nighttime systolic BP variability is independently associated with large arch plaque. These findings may have important implications in gaining further insights into the mechanism of arch plaque formation and progression.     

Serum levels of metalloproteinases and their inhibitors during infection with pathogens having integrin receptor-mediated cellular entry

Abstract Background: Matrix metalloproteinases (MMPs) are a family of proteolytic enzymes with numerous roles in the normal immune response to infection. However, excess MMP activity following infection may lead to immunopathological processes that cause tissue damage. Their activity in normal tissues is subject to tight control, which is regulated by its specific endogenous tissue inhibitors (TIMPs). It is known that MMPs bind to cell surface proteins (e.g. integrins) and that such interactions can have modulatory effects on MMP functionality. The objective of this study was to determine whether there are differences in MMP and TIMP production during the acute phase of infection with different pathogens that use β-integrins as their receptors for cell entry. Methods: We measured the total amounts of soluble MMP-2, MMP-9, TIMP-1, and TIMP-2 in the sera from patients infected with Dobrava virus (DOBV), Coxiella burnetii, or uropathogenic Escherichia coli. Statistical analyses were used to correlate MMP/TIMP serum levels with different clinical laboratory parameters. Results: The results showed that both of the bacterial infections generally manifested the stronger effect on MMP production, while in contrast, viral infection introduced stronger changes to metalloproteinase inhibitors. MMPs and TIMPs were significantly correlated with some of the clinical laboratory parameters in both bacterial infections, but no correlations were found for DOBV infection. Conclusions: These findings suggest diverse mechanisms by which MMP activity could be implicated in the pathology of these 2 bacterial infections versus the viral DOBV infection, despite the type of their cellular entry receptors.     

Analysis of granulysin-mediated cytotoxicity in peripheral blood of patients with psoriatic arthritis

The objective of the present study was to investigate possible changes in granulysin (GNLY)-mediated cytotoxicity of peripheral blood lymphocytes in psoriatic arthritis (PsA) patients with respect to different phases of the disease. We prospectively enrolled 25 PsA patients in the active phase, 26 PsA patients in remission and 24 healthy controls. The simultaneous detection of intracellular GNLY and cell surface antigens (CD3 and CD56) was performed with flow cytometry. GNLY apoptotic protein was visualised by immunocytochemistry. Natural killer (NK) cell cytotoxicity was analysed with a cytotoxicity assay against human erythroleukaemia K-562 cells. The percentage of GNLY(+) cells did not differ significantly between PsA patients in the acute phase and those in remission; however, it was always higher than in healthy examinees due to the increased percentage of GNLY(+) cells within T cells, NKT cells, and both, and in the CD56(+dim) and CD56(+bright) NK subsets. The mean fluorescence intensity for GNLY was higher in all lymphocyte subpopulations in the acute phase than in remission and in healthy controls. Accordingly, GNLY-mediated NK cell cytotoxicity against K-562 cells of active phase PsA patients was significantly higher than that in patients in remission or in healthy controls. These findings demonstrated the involvement of GNLY in the worsening of PsA and suggested that GNLY mediated the development of joint lesions.     

Training implications of maximal forces on a computer-controlled and motor-driven leg press by age group, sex, footplate direction, and speed

Strength training that overloads lengthening muscle fibers may result in greater strength gains with less effort and perceived exertion than conventional training modalities. This study evaluates a device capable of this overloading (a motor-driven and computer-controlled leg press) to develop recommendations for future training interventions. Unimpaired younger and older men and women (7/group, total n=28) performed three maximal-effort trials for both directions of footplate motion (IN and OUT) at three speed profiles (knee rotation speeds of 15, 25, and 35°/s) on a motor-driven and computer-controlled leg press. Normalized forces were tested for effects of age group, sex, direction of footplate motion, and knee rotation speed. Peak forces were 57% greater for younger and 20% greater for IN. Trends of greater IN relative to OUT forces (IN overloading) were present in women, but this was due to an inverse correlation between strength and IN overloading that was independent of age group and sex. Leg press strength training on a device that is capable of overloading lengthening muscle fibers is a promising new training method that appears to have the greatest potential benefits for the weakest participants. Training target profiles on the device tested and others similar to it should be set based on participant-specific maximums across the ROM in both IN and OUT directions at a speed in the middle of the range to be trained.     

Multiple co-infections of rodents with hantaviruses, Leptospira, and Babesia in Croatia

Hantaviruses, Leptospira spp., and Babesia spp. are rodent-borne pathogens present worldwide. We studied multiple co-infections of small rodents in Croatia with all three pathogens. Twenty-eight Apodemus flavicollis and 16 Myodes glareolus were tested for the presence of hantavirus RNA by real-time RT-PCR, Leptospira strains by renoculture method and Babesia DNA by PCR. Anti-hantavirus antibodies and anti-Leptospira antibodies were detected by serological methods. Very high infection rates with each pathogen were found in A. flavicollis: 20 of 28 rodents (71%) were infected with Dobrava virus, 13 rodents (46%) were infected with Leptospira, and 5 rodents (18%) were infected with Babesia. Multiple co-infections with all three pathogens were found in 3 of 28 (11%) A. flavicollis animals, suggesting that the same rodent host can be infected with several pathogens at the same time. Dual infections with both hantaviruses and Leptospira were found in 7 of 44 rodents (16%), with hantaviruses and Babesia in 2 rodents (5%), and double infection with both Leptospira and Babesia were found in 1 rodent (2%). Since hantaviruses, Leptospira, and Babesia have similar geographical distributions, it is to be expected that in other parts of the world multiple co-infections, representing a serious threat to public health, can be found.