Overview of HOMEChem: House Observations of Microbial and Environmental Chemistry.

The House Observations of Microbial and Environmental Chemistry (HOMEChem) study is a collaborative field investigation designed to probe how everyday activities influence the emissions, chemical transformations and removal of trace gases and particles in indoor air. Sequential and layered experiments in a research house included cooking, cleaning, variable occupancy, and window-opening. This paper describes the overall design of HOMEChem and presents preliminary case studies investigating the concentrations of reactive trace gases, aerosol particles, and surface films. Cooking was a large source of VOCs, CO2, NOx, and particles. By number, cooking particles were predominantly in the ultrafine mode. Organic aerosol dominated the submicron mass, and, while variable between meals and throughout the cooking process, was dominated by components of hydrocarbon character and low oxygen content, similar to cooking oil. Air exchange in the house ensured that cooking particles were present for only short periods. During unoccupied background intervals, particle concentrations were lower indoors than outdoors. The cooling coils of the house ventilation system induced cyclic changes in water soluble gases. Even during unoccupied periods, concentrations of many organic trace gases were higher indoors than outdoors, consistent with housing materials being potential sources of these compounds to the outdoor environment. Organic material accumulated on indoor surfaces, and exhibited chemical signatures similar to indoor organic aerosol.

Dilated coronary sinus mimicking posterior left ventricular aneurysm.

Dilation of the coronary sinus is mostly a congenital lesion. As acquired lesion it was found to be associated with poor left ventricular function. In the present case an angiographic diagnosed posterior left ventricular aneurysm was during surgery found to be a dilated coronary sinus. Preoperative left ventricular function was normal.

Unsuspected idiopathic mediastinal fibrosis complicating coronary bypass operation.

A 66-year-old woman was referred for coronary bypass operation to the left anterior descending and the circumflex arteries. She had a systemic inflammatory process of unknown origin. On opening the pericardium, fibrotic plaques encircling the entire ascending aorta were found. Aortic cannulation and proximal anastomosis of the planned vein graft were impossible. The right internal mammary was anastomosed to the left anterior descending artery, the left to the obtuse marginal after femoral arterial cannulation. Pathologic examination revealed idiopathic mediastinal fibrosis.

The endothelial nitric-oxide synthase-caveolin regulatory cycle.

Nitric oxide production in the vascular endothelium is promoted by diverse agonists that transiently increase intracellular Ca2+ concentration and activate the endothelial nitric-oxide synthase (eNOS), a Ca2+/calmodulin-dependent enzyme. eNOS is acylated by the fatty acids myristate and palmitate and is targeted thereby to plasmalemmal signal-transducing domains termed caveolae. eNOS enzyme activity is markedly attenuated by its interactions with caveolin, the structural scaffolding protein of caveolae. We have discovered that in living cells, the eNOS-caveolin heteromeric complex undergoes cycles of dissociation and re-association modulated by Ca2+-mobilizing agonists. Calcium ionophore A23187 and the muscarinic cholinergic agonist carbachol both promote the dissociation of eNOS from caveolin in cultured cells, associated with translocation of eNOS from caveolae. As [Ca2+]i returns to basal levels, eNOS re-associates with caveolin, and the inhibited enzyme complex is then restored to caveolae, a process accelerated by palmitoylation of the enzyme. These data establish an eNOS-caveolin regulatory cycle, wherein enzyme activation is modulated by reversible protein-protein interactions controlled by Ca2+/calmodulin and by enzyme palmitoylation. Alterations in this cycle are likely to have an important influence on nitric oxide-dependent signaling in the vascular wall.

T cell recognition and cytokine production elicited by common and type-specific glycoproteins of herpes simplex virus type 1 and type 2.

T cell recognition of common and type-specific herpes simplex virus (HSV) glycoproteins was measured in 72 subjects. T cells were stimulated with whole HSV-2 antigen and glycoproteins gB2, gD2, and gG2. T cell proliferation in response to HSV-2 antigen and gG2 was significantly higher in subjects with HSV-2 infection than in those with HSV-1 infection only; responses to gB2 and gD2 were the same. T helper (Th) type 1 and Th2 cytokine production in response to whole HSV-2 antigen, gB2, and gD2 was evaluated in 33 subjects. Interleukin (IL)-2 and interferon-gamma responses to most antigens were significantly higher among HSV-2-seropositive subjects than among seronegative subjects. IL-4 synthesis was negligible; IL-10 was produced in seronegative and seropositive persons, but HSV-2 antigen responses were significantly higher in HSV-2-seropositive persons. Naturally acquired immunity to HSV involves T cell recognition of common and type-specific glycoproteins, prominent Th1 responses, and discordant Th2 responses with little IL-4 but substantial IL-10 production.