Lung transplantation in a recipient with novel 2009 H1N1 influenza: lessons learned.

Immunosuppressed patients are at an increased risk for severe disease from influenza A (H1N1). We report a case of a patient who died of septic complications from H1N1 acquired at the time of single lung transplant.

Heart transplantation.

Over the past 40 years, heart transplantation has become a routine treatment for end-stage heart failure. Over 3000 heart transplants are performed annually. Despite improvements in short-term outcomes, long-term survival remains limited. Current efforts remain directed at alleviating the shortage of donor organs, developing effective treatments for chronic rejection, and improving mechanical circulatory support for heart failure.

Lung transplantation: past, present, and future.

Lung transplantation (LTx) is an established therapy for end-stage lung disease (ESLD). Survival after LTx is limited by infection and rejection, particularly bronchiolitis obliterans syndrome (BOS). New techniques with the potential to increase donor lung supply and prevent rejection continue to evolve. These developments hold promise for improved outcomes for a greater number of patients.

Rantes production during development of cardiac allograft vasculopathy.

BACKGROUND: RANTES (regulated on activation, normal T cell expressed and secreted) production has been shown to correlate with mononuclear cell recruitment and precede intimal thickening in cardiac allograft vasculopathy (CAV). However, the cells that produce RANTES in CAV are undefined. Therefore, in an MHC II-mismatched murine model of CAV, we sought to (1) define the cellular sources of RANTES and (2) determine the role of CD4+ lymphocytes in RANTES production during CAV development. METHODS: B6.CH-2bm12 strain donor hearts were transplanted heterotopically into wild-type (WT) or CD4 knockout (CD4KO) C57BL/6 mice (MHC II mismatch). No immunosuppression was used. Recipients were sacrificed at 7, 14, and 24 days. Intragraft RANTES gene expression and protein levels were determined with ribonuclease protection assay and ELISA, respectively. At days 7 and 24, RANTES production by graft-infiltrating cells was defined with intracellular RANTES staining and multicolor FACS analysis. Intimal thickening was quantitated morphometrically. In murine hearts and in six explanted human hearts with advanced CAV, RANTES was also localized immunohistochemically. RESULTS: NK, NKT, and gammadelta+ cells, in addition to CD4+, CD8+ lymphocytes, and CD11b+ macrophages, produced RANTES in early and late stages of CAV. RANTES-producing NK, NKT, and gammadelta+ cells tripled in number during CAV development; by day 24, NK and gammadelta+ cells each outnumbered CD4+ lymphocytes and CD11b+ macrophages. The presence of CD4+ lymphocytes was required for sustained RANTES production in allografts, which correlated with mononuclear cell recruitment and preceded intimal thickening. In murine and explanted human hearts with advanced CAV, RANTES immunolocalized with graft-infiltrating mononuclear cells and vessel wall cells. CONCLUSIONS: We present evidence that other cell types in addition to CD4+, CD8+ T lymphocytes, and CD11b+ macrophages contribute significantly to RANTES production in CAV. In this MHC II-mismatched murine model of CAV, sustained RANTES production requires CD4+ lymphocytes, correlates with mononuclear cell recruitment, and precedes intimal thickening. In experimental and human CAV, vessel wall cells may also produce RANTES. Interventions aimed at inhibiting RANTES production in CAV may need to target several types of cells, and neutralization of RANTES bioactivity may reduce mononuclear cell recruitment and CAV development.

Early and late chemokine production correlates with cellular recruitment in cardiac allograft vasculopathy.

BACKGROUND: Cardiac allograft vasculopathy (CAV) remains the leading cause of late mortality in heart transplant recipients. Activated T lymphocytes and macrophages infiltrate the donor heart before vascular intimal thickening develops, but the specific mediators of mononuclear cell recruitment leading to CAV are unknown. Therefore, we sought to define the relationship between chemokine gene expression and production, T lymphocyte and macrophage recruitment, and intimal thickening in a murine model of CAV. METHODS: B10.A or B10.BR strain hearts were transplanted heterotopically into B10.BR mice. Recipients were killed at 1, 4, 7, 14, and 30 days. Donor hearts were assayed for chemokine gene expression with ribonuclease protection and for protein with ELISA. Intragraft cellular infiltration was defined immunohistochemically. Intimal thickening was quantitated morphometrically. RESULTS: Early and late patterns of intragraft chemokine expression associated with distinct cellular infiltration were identified. First, transient MIP-2 and MCP-1/JE production in isografts and allografts correlated with neutrophil and macrophage infiltration. MCP-1/JE production and macrophage infiltration was greater in allografts than isografts. Second, allografts demonstrated sustained lymphotactin, RANTES, and IP-10 expression, beginning at day 4, correlating with persistent macrophage and T lymphocyte infiltration. Intimal thickening became evident at 14 days. Isografts did not display the late pattern of sustained chemokine gene expression, cellular infiltration, or intimal thickening. CONCLUSIONS: Transient, early MIP-2, and MCP-1/JE production in isografts and allografts correlated with neutrophil and macrophage recruitment, and is likely related to ischemia-reperfusion. In allografts, the delayed induction of chemokines specific for macrophages and T lymphocytes correlated with mononuclear cell infiltration and preceded intimal thickening. This study thus demonstrates a dual pattern of chemokine induction correlating with intragraft mononuclear cell recruitment, associated with ischemia-reperfusion and CAV development. Chemokine-directed interventions may interfere with leukocyte trafficking and inhibit CAV development.

Severe regional ischemia alters coronary flow reserve in the remote perfusion area.

BACKGROUND: Clinical and experimental studies suggest that coronary flow reserve (CFR) may be abnormal in regions remote from myocardial infarction. We sought to determine the possible relation among stenosis severity, ischemic dysfunction, and impairment of CFR in remote regions. METHODS AND RESULTS: In 7 open-chest dogs, acute graded left circumflex (LCX) ischemia was created and maintained based on measurement of the transstenotic (aortic-distal LCX) pressure gradient (measured in millimeters of mercury). Regional thickening was assessed with sonomicrometers. Regional myocardial flow was assessed at rest with radiolabeled microspheres. Doppler flow probes were placed on proximal LCX and left anterior descending (LAD) arteries to measure resting flow and CFR in response to intracoronary injection of adenosine (36 microg). These parameters were assessed under baseline conditions and during transstenotic gradients of 10, 20, 30, and 40 mm Hg. Increasing LCX stenosis severity caused progressive impairment of LCX CFR: baseline (2.22+/-0.10), stenosis 10 (1.80+/-0.06), stenosis 20 (1.56+/-0.08), stenosis 30 (1.30+/-0.04), and stenosis 40 (1.17+/-0.06) (P<.01 vs. baseline). Remote LAD CFR was not altered by mild to moderate LCX stenosis (baseline [2.33+/-0.19]; stenosis 10 [2.30+/-0.25]; stenosis 20 [2.15+/-0.26]). However, critical LCX stenosis producing mild to moderate reduction in thickening in the ischemic region was associated with a significant impairment of LAD CFR: stenosis 30 (1.90+/-0.26) and stenosis 40 (1.80+/-0.22) (P<.01 vs. baseline). These changes in remote CFR persisted after correction for changes in the rate-pressure product. CONCLUSION: In an acute canine model of progressive LCX coronary stenosis, CFR was impaired in both ischemic and remote nonischemic regions in association with mild to moderate ischemic-induced regional myocardial dysfunction. Thus pharmacologic vasodilation provoked only mild heterogeneity in CFR in the presence of a critical LCX stenosis as a result of concurrent reduction of LAD CFR. This phenomenon warrants further clinical and experimental investigation because it may affect detection of flow heterogeneity during acute ischemia (which induced myocardial dysfunction).

Effect of fat reduction on chemical composition, proteolysis, functionality, and yield of Mozzarella cheese.

Mozzarella cheese was made from skim milk standardized with cream (unhomogenized, 40% milk fat) to achieve four different target fat percentages in the cheese (ca. 5, 10, 15, and 25%). No statistically significant differences were detected for cheese manufacturing time, stretching time, concentration of salt in the moisture phase, pH, or calcium as a percentage of the protein in the cheese between treatments. As the fat percentage was reduced, there was an increase in the moisture and protein content of the cheese. However, because the moisture did not replace the fat on an equal basis, there was a significant decrease in the moisture in the nonfat substance in the cheese as the fat percentage was reduced. This decrease in total filler volume (fat plus moisture) was associated with an increase in the hardness of the unmelted cheese. Whiteness and opacity of the unmelted cheese decreased as the fat content decreased. Pizza baking performance, meltability, and free oil release significantly decreased as the fat percentage decreased. The minimum amount of free oil release necessary to obtain proper functionality during pizza baking was between 0.22 and 2.52 g of fat/100 g of cheese. Actual cheese yield was about 30% lower for cheese containing 5% fat than for cheese with 25% fat. Maximizing fat recovery in the cheese becomes less important to maintain high cheese yield, and moisture control and the retention of solids in the water phase become more important as the fat content of the cheese is reduced.

Limitations of dobutamine for enhancing flow heterogeneity in the presence of single coronary stenosis: implications for technetium-99m-sestamibi imaging.

UNLABELLED: Dobutamine is used as an alternative to exercise in conjunction with 99mTc-sestamibi SPECT perfusion imaging for detection of coronary artery disease. However, the use of quantitative dobutamine 99mTc-sestamibi SPECT imaging for enhanced detection of coronary stenosis has not been established. The goal of this study is to examine the effects of dobutamine stress on regional myocardial blood flow and relative myocardial 99mTc-sestamibi activity in the presence of a single-vessel stenosis. METHODS: In six open-chest dogs with left circumflex artery stenosis, radiolabeled microspheres were injected during baseline, severe stenosis and peak dobutamine stress (10 microg/kg/min). Technetium-99m-sestamibi was injected intravenously at peak dobutamine. Hearts were excised 20 min after 99mTc-sestamibi injection for SPECT imaging and post-mortem gamma-well counting. RESULTS: Dobutamine significantly increased heart rate, rate-pressure product and the first derivative of left ventricular pressure. Ischemic zone (left circumflex) myocardial blood flows (in ml/min/g) were: baseline, 0.92 +/- 0.15; stenosis, 0.65 +/- 0.16; and dobutamine, 1.19 +/- 0.38. Nonischemic zone myocardial blood flows were: baseline, 0.99 +/- 0.18; stenosis, 1.01 +/- 0.12; and dobutamine, 1.94 +/- 0.32 (p < 0.01 versus stenosis). Ischemic flows, expressed as percentages of nonischemic flows, were: baseline, 94% +/- 2%; stenosis, 63% +/- 11% (p < 0.05 versus baseline) and dobutamine, 60% +/- 12% (p was not significant versus stenosis). Technetium-99m-sestamibi activity in the ischemic zone (75% +/- 6% nonischemic) underestimated the relative flow deficit produced during dobutamine stress (p = 0.056). Myocardial 99mTc-sestamibi activity correlated with flow when flow was less than 1.0 ml/min/g. At higher flow ranges (1.0 ml/min/g-3.5 ml/min/g), 99mTc-sestamibi did not track flow. CONCLUSION: In a canine model of flow-limiting, single-vessel stenosis, dobutamine (10 microg/kg/min) did not augment flow heterogeneity. In addition, relative myocardial 99mTc-sestamibi activity underestimated microsphere flow at higher flows induced by dobutamine, leading to underestimation of ischemia. These findings suggest that dobutamine stress 99mTc-sestamibi scintigraphy may underestimate the relative flow deficit.

Cheddar cheese: influence of milking frequency and stage of lactation on composition and yield.

Cheddar cheese was made from milk collected from two groups of cows milked either two or three times daily during early, mid, and late lactation. Milk from cows in late lactation had lower casein as a percentage of true protein and a higher acid degree value than did milk from cows in early lactation. Milk from cows milked three times daily had lower concentrations of milk fat and casein and higher acid degree values than did milk from cows milked twice daily, and thus this milk would be expected to result in decreased cheese yield. Cheese composition was not affected by milking frequency. Stage of lactation effects on cheese composition were confined to differences in salt content and a trend for higher moisture in cheese made from milk of cows in late lactation. Stage of lactation influenced the pH and degradation of alpha s-casein in cheese during aging. Fat and protein losses in whey at draining were higher for milk from cows in late lactation than from milk from cows in early lactation. The typical differences in fatty acid composition of milk from cows in early lactation that cause lower melting point may have caused higher fat loss in press whey. Fat loss in whey at draining was higher in cheese made from milk from cows milked three times daily than in cheese made from milk from cows milked twice daily, but the protein loss was not influenced. The ADV of milk was positively correlated to the fat loss in whey. Lower recoveries of fat and protein in cheese from milk of cows in late lactation were observed and may cause small but economically important decreases in cheese yield. Low SCC of milk from cows in late lactation may have minimized the changes in cheese composition and yield from stage of lactation.