Mechanisms of Cardiovascular Disease in the Setting of HIV Infection

Although the initial reports of increased cardiovascular (CV) disease in the setting of advanced AIDS were reported approximately 30 years ago, advances in antiretroviral therapy and immediate initiation of therapy on diagnosis have transformed what was once a deadly infectious disease into a chronic health condition. Accordingly, the types of CV diseases occurring in HIV have shifted from pericardial effusions and dilated cardiomyopathy to atherosclerosis and heart failure. The underlying pathophysiology of HIV-associated CV disease remains poorly understood, partly because of the rapidly evolving nature of HIV treatment and because clinical endpoints take many years to develop. The gut plays an important role in the early pathogenesis of HIV infection as HIV preferentially infects CD4+ T cells, 80% of which are located in gut mucosa. The loss of these T cells damages gut mucosa resulting in increased gut permeability and microbial translocation, which incites chronic inflammation and immune activation. Antiretroviral therapy does not cure HIV infection and immune abnormalities persist. These abnormalities correlate with mortality and CV events. The effects of antiretroviral therapy on CV risk are complex; treatment reduces inflammation and other markers of CV risk but induces lipid abnormalities, most commonly hypertriglyceridemia. On a molecular level, monocytes/macrophages, platelet reactivity, and immune cell activation, which play a role in the general population, may be heightened in the setting of HIV and contribute to HIV-associated atherosclerosis. Chronic inflammation represents an inviting therapeutic target in HIV, as it does in uninfected persons with atherosclerosis.     

Prolonged afebrile nonproductive cough illnesses in American soldiers in Korea: a serological search for causation.

A serological study was undertaken to investigate infections in active-duty United States soldiers with illnesses characterized by prolonged, afebrile, nonproductive coughs. Fifty-four soldiers were enrolled with such illness of >/=2 weeks' duration (case patients) along with 55 well soldiers (control subjects). Serum samples were tested for IgG and IgA antibody to 3 Bordetella pertussis antigens, pertussis agglutinins, IgM antibodies to Mycoplasma pneumoniae, IgM and IgG antibodies to Chlamydia pneumoniae, and IgM antibody to adenoviruses. Forty-six case patients (85%) had evidence of recent infection with Bordetella species, M. pneumoniae, or C. pneumoniae, and many had evidence of mixed infections; there were 27 Bordetella species, 20 C. pneumoniae, and 33 M. pneumoniae recent infections. Fifteen case patients had high titers of IgG or IgA to B. pertussis filamentous hemagglutinin without high titers of antibodies to other B. pertussis antigens, which suggested the presence of cross-reacting antibodies to M. pneumoniae and perhaps C. pneumoniae or unidentified infectious agent or agents. Since illnesses due to Bordetella species, M. pneumoniae, and C. pneumoniae can all be treated with macrolide antibiotics and B. pertussis illness can be prevented by immunization, and since military readiness was affected in 63% of the cases, it seems important to conduct further studies in military populations.     

Gait and kinematics of the trunk and lower extremities in stair ascent using quadricane in healthy subjects

Different cane placement methods require different gait patterns and ranges of motion either at the trunk or lower extremities. The aim of this study was to examine the effect of cane placement on body biomechanics in stair ascent (SA) in 16 healthy adults (9 women, 7 men) aged 27.2+/-3.2 years old. The height and weight of the women and men were 160.8+/-5.4 cm and 54.1+/-8.1 kg, and 170.8+/-3.9 cm and 69.6+/-5.6 kg, respectively. Three-dimensional motion data were collected in non-reciprocally SA associated with following methods: (1) dominant foot stepped up first, then the opposite foot without a cane (NC); (2) forward placement of a quadricane followed by the ipsilateral foot, then contralateral foot (FCI); (3) forward cane placement followed by the contralateral foot, then ipsilateral foot (FCC); (4) ipsilateral foot stepping up first, followed by the contralateral foot and the cane (LCI); (5) contralateral foot stepping up, followed by the ipsilateral foot and cane (LCC). LCI and LCC were considered as lateral cane placement. Temporal gait parameters, kinematics of the trunk and lower extremities were calculated. The results indicate that the cane placement had significant effect on the kinematics of the trunk and lower extremities. The main differences between forward and lateral cane placement were flexion and side flexion of the trunk, and flexion of the leading and opposite hip and knee. Hip rotation and abduction, and ankle plantar and dorsiflexion were different between contralateral and ipsilateral cane placements.     

Role of thrombotic and fibrinolytic factors in acute coronary syndromes

There is a growing body of literature concerning the contribution of hemostatic factors to the development of cardiovascular disease. The mechanisms of the coagulation/fibrinolytic system are complicated and one factor is intimately interrelated with another; thus the contribution of each factor cannot be clearly understood, unless hemostatic factors are considered in accordance with endothelial function and vessel morphology. Although there are many clinical studies about the correlation between hemostatic factors and cardiovascular risk, the results are inconsistent and conflicting at times. Fibrinogen and D-dimer are associated with atherosclerosis or coronary events across multiple studies, even after multivariate adjustment. But the hemostatic factors are intimately correlated, so it can be said that focusing on one to the exclusion of others is inappropriate. The clinical trials with statins or angiotensin converting enzyme inhibitors have shown favorable effects on the prognosis of cardiovascular disease. The study of hemostatic factors in relation to these drugs has provided insights into understanding how these drugs produce beneficial effects.