Sinusoidal transmission grating spectrometer for extreme ultraviolet measurement.

Spectral measurements play a vital role in understanding laser-plasma interactions. The ability to accurately measure the spectrum of radiation sources is crucial for unraveling the underlying physics. In this article, we introduce a novel approach that significantly enhances the efficiency of binary sinusoidal transmission grating spectrometers . The grating was tailored especially for Extreme Ultraviolet (EUV) measurements. The new design, High Contrast Sinusoidal Transmission Grating (HCSTG), not only suppresses high diffraction orders and retains the advantageous properties of previous designs but also exhibits a fourfold improvement in first-order efficiency. In addition, the HCSTG offers exceptional purity in the first order due to effectively eliminating half-order contributions from the diffraction pattern. The HCSTG spectrometer was employed to measure the emission of laser-produced Sn plasma in the 1-50 nm spectral range, achieving a spectral resolution of λ/Δλ = 60. We provide a comprehensive analysis comparing the diffraction patterns of different STGs, highlighting the advantages offered by the HCSTG design. This novel, efficiency-enhanced HCSTG spectrometer opens up new possibilities for accurate and sensitive EUV spectral measurements.

Conditioned medium from hypoxic cells protects cardiomyocytes against ischemia.

The hypothesis of the present study is that cardiomyocytes subjected to prolonged ischemia, may release survival factors that will protect new cardiac cells from ischemic stress. We exposed neonatal rat cardiomyocyte primary cultures to hypoxia, collected the supernatant, treated intact cardiac cells by this posthypoxic supernatant, and exposed them to hypoxia. The results show cardioprotection of the treated cells compared with the untreated ones. We named the collected posthypoxic supernatant "conditioned medium" (CM), which acts in a dose-dependent manner to protect new cardiac cells from hypoxia: 100 or 75% of CM diluted in phosphate-buffered saline (PBS) protected cells as if they were not exposed to hypoxia (P < 0.001). When CM was removed from the cells before hypoxia, protection was not observed. CM also protected skeletal muscle cultures from hypoxia, but not cardiac cells against H(2)O(2)-induced cell damage. Finally, CM treatment protected the isolated heart in Langendorff set-up against ischemia. Smaller infarct size (9.9 ± 4.4% vs. 28.3 ± 8.5%, P < 0.05), better Rate Pressure Product (67 ± 11% vs. 48.6 ± 13.4%, P < 0.05) and better rate of contraction and relaxation were observed following ischemia and reperfusion (1341 ± 399 mmHg/s vs. 951 ± 349 mmHg/s, P < 0.05 and 1053 ± 347 mmHg/s vs. 736 ± 314 mmHg/s, P < 0.05). To conclude, there are factors that are released from the heart cells subjected to ischemia/hypoxia that protects cardiomyocytes from ischemic stress.

UTP reduces infarct size and improves mice heart function after myocardial infarct via P2Y2 receptor.

Pyrimidine nucleotides are signaling molecules, which activate G protein-coupled membrane receptors of the P2Y family. P2Y(2) and P2Y(4) receptors are part of the P2Y family, which is composed of 8 subtypes that have been cloned and functionally defined. We have previously found that uridine-5'-triphosphate (UTP) reduces infarct size and improves cardiac function following myocardial infarct (MI). The aim of the present study was to determine the role of P2Y(2) receptor in cardiac protection following MI using knockout (KO) mice, in vivo and wild type (WT) for controls. In both experimental groups used (WT and P2Y(2)(-/-) receptor KO mice) there were 3 subgroups: sham, MI, and MI+UTP. 24h post MI we performed echocardiography and measured infarct size using triphenyl tetrazolium chloride (TTC) staining on all mice. Fractional shortening (FS) was higher in WT UTP-treated mice than the MI group (44.7±4.08% vs. 33.5±2.7% respectively, p<0.001). However, the FS of P2Y(2)(-/-) receptor KO mice were not affected by UTP treatment (34.7±5.3% vs. 35.9±2.9%). Similar results were obtained with TTC and hematoxylin and eosin stainings. Moreover, troponin T measurements demonstrated reduced myocardial damage in WT mice pretreated with UTP vs. untreated mice (8.8±4.6 vs. 12±3.1 p<0.05). In contrast, P2Y(2)(-/-) receptor KO mice pretreated with UTP did not demonstrate reduced myocardial damage. These results indicate that the P2Y(2) receptor mediates UTP cardioprotection, in vivo.

Is gender an independent risk factor for coronary bypass grafting?

BACKGROUND: Postoperative mortality after coronary artery bypass grafting (CABG) surgery is traditionally considered to be influenced by gender. However, the data are conflicting and it is not clear whether gender is a true independent risk factor for death in this setting. We analyzed our database to determine whether gender is an independent risk factor for death after CABG. PATIENTS AND DESIGN: A retrospective analysis of 1 758 isolated first-time coronary artery bypass graft patients treated between 2003 and 2005 was conducted in the Department of Cardiothoracic Surgery of Rabin Medical Center, a major tertiary facility in Israel. RESULTS: The female patients had a distinctly different pre- and intraoperative profile compared with the male patients, and significantly higher postoperative mortality (p < 0.05). On a propensity scoring of 359 matched pairs, the risk factors for death were found to be severe left ventricular dysfunction, chronic obstructive pulmonary disease, and use of an intra-aortic balloon pump (p < 0.05). The addition of intraoperative data to the model yielded only cardiopulmonary bypass time and use of an intra-aortic balloon pump as risk factors for death (p < 0.05). Validation with the bootstrap technique revealed that strong predictors of death (> 50 % of the sample) were cardiopulmonary bypass time, use of an intra-aortic balloon pump, and, to a lesser extent, chronic obstructive pulmonary disease. Female gender was not found to be an independent risk factor for death after coronary artery bypass graft. CONCLUSIONS: Female gender is apparently not an independent risk factor for coronary artery bypass graft mortality in this patient group.

A highly unusual right atrial mass presented in two women.

Intravenous leiomyomatosis is a rare, benign neoplasm of the uterine, affecting adult women. We report two cases in whom intravenous leiomyomatosis extended through the inferior vena cava into the right heart chambers and the pulmonary artery. Both patients underwent staged operation with excision of the cardiac and primary tumour. The differential diagnosis of a right atrial mass in middle-aged women should include intravenous leiomyomatosis.

Cardiac surgery in patients on chronic hemodialysis: short and long-term survival.

OBJECTIVE: Open-heart surgery carries a high risk for hemodialysis patients. This study focuses on the short and long-term outcomes of hemodialysis patients undergoing heart surgery. DESIGN: The study was carried out as a retrospective analysis in the Department of Cardiothoracic Surgery in a large university-affiliated hospital. PATIENTS: 115 hemodialysis patients underwent cardiac surgery in our department between 1 July 1996 and 31 July 2006. 67.5 % (77 patients) underwent isolated coronary artery bypass grafting (CABG), 13.2 % (15 patients) underwent isolated aortic valve replacement (AVR) and 20.2 % (23 patients) underwent mitral valve surgery or combined valve and coronary artery bypass grafting or multiple valve surgery. METHODS: The relationship between several variables (age, sex, hypertension, diabetes, and previous myocardial infarction, type of disease, preoperative ejection fraction, and congestive heart failure) and operative (30 days) mortality and late survival was analyzed. RESULTS: The overall 30-day mortality was 18.3 % (21 patients). It was 13 % (10/77 patients) for the isolated CABG group and 13.3 % (2/15) for the isolated AVR group. Patients undergoing combined valve and coronary surgery or multiple valve surgery had a higher perioperative mortality of 39.1 % (9/23) compared to the isolated CABG and isolated AVR patients. Perioperative death was also higher in patients with moderate and severe LV dysfunction, and in patients with diabetes. The duration of dialysis periods was not related to perioperative death. Mean follow-up was 26.4 +/- 29.7 months (0.1 to 104 months). Actuarial survival at 1 year and 5 years was 76 % and 55 % for isolated CABG, 59 % and 21 % for isolated AVR, and 44 % and 33 % for all other cases, respectively (log rank P = 0.001). CONCLUSION: Patients on dialysis have a high risk of perioperative mortality and poor long-term survival rates. Mortality is higher and survival is worse after combined CABG and valve-related procedures or multiple valve surgery than after isolated CABG and AVR.

Number needed to treat: analyzing of the effectiveness of thoracoabdominal aortic repair.

BACKGROUND: Number needed to treat (NNT) is a method used to calculate the number of patients who need to be treated to prevent one adverse outcome. To analyze the effectiveness of thoracoabdominal and descending thoracic aortic aneurysm repair, we computed the NNT required to prevent one death. METHODS: Between Jan 1991 and Feb 2003, we repaired 1004 aneurysms of the descending thoracic and thoracoabdominal aorta. We followed the patients from surgery until death. Five-year actuarial survival in our population was computed by the Kaplan-Meier method. Natural history data for comparison were taken from the population-based work of Bickerstaff et al., 1982. NNT was calculated as the reciprocal of the risk difference at 5 years. 95% confidence intervals were computed by the method of Daly. RESULTS: Five-year mortality in the population-based cohort was 87 vs. 39% in our treated population, for a risk difference of 48%. 1/0.48=2, indicating that two patients need to be treated to prevent one death at 5 years (95% CI 1.8-2.5, p<0.0001). CONCLUSION: An NNT of two demonstrates the effectiveness of surgical repair of descending thoracic and thoracoabdominal aortic aneurysms when compared to the natural history. By comparison, carotid endarterectomy for symptomatic lesions >70% has an NNT of 15 to prevent a single stroke or death. NNT can also be applied to aneurysm size criteria to estimate the effort required to prevent death or rupture for a given aneurysm size.

Chronic aortic dissection not a risk factor for neurologic deficit in thoracoabdominal aortic aneurysm repair.

OBJECTIVE: chronic aortic dissection has long been considered a risk factor for neurologic deficit following thoracoabdominal aortic aneurysm (TAA) surgery. We reviewed our experience with regard to aneurysm extent and the use of adjunct, (distal aortic perfusion/cerebrospinal fluid drainage), and examined the impact of these factors on neurologic deficit among chronic dissection and non-dissection cases. METHODS: between February 1991 and March 2001, we repaired 800 aneurysms of the descending thoracic and thoracoabdominal aorta. Seven hundred and twenty-nine cases were elective; 196 chronic dissection, 533 non-dissection. 182/729 (24.9%) were TAA extent II. Among these, 61/182 (33%) involved chronic dissection. Adjunct was used in 507/729 (69.6%). We conducted detailed multivariate analyses to isolate the impact of chronic aortic dissection on neurologic morbidity, with other important risk factors taken into account. RESULTS: overall, 32/729 (4.4%) patients had neurologic deficit upon awakening; 7/196 (3.6%) in chronic dissections, and 25/533 (4.7%) in non-dissections. Adjunct had a major effect, reducing neurologic deficit in TAA extent II from 10/36 (27.8%) to 10/146 (6.9%) (p=0.001). However, in univariate and multivariate analysis, chronic dissection did not increase the risk of neurologic deficit, regardless of extent or mode of treatment. CONCLUSION: in contrast to previous reports, we determined that chronic aortic dissection is not a risk factor in TAA patients.

Neurologic outcome after thoracic and thoracoabdominal aortic aneurysm repair.

BACKGROUND: Neurologic deficit (paraparesis and paraplegia) after repair of the thoracic and thoracoabdominal aorta remains a devastating complication. The purpose of this study was to determine the effect of cerebrospinal fluid drainage and distal aortic perfusion upon neurologic outcome during repair of thoracic and thoracoabdominal aortic aneurysm (TAAA) repair. METHODS: Between February 1991 and March 2000, we performed 654 repairs of the thoracic and thoracoabdominal aorta. The median age was 67 years and 420 (64%) patients were male. Forty-five cases (6.9%) were performed emergently. Distribution of TAAA was the following: extent I, 164 (25%); extent II, 165 (25%); extent III, 61 (9%); extent IV, 95 (15%); extent V, 23 (3.5%); and descending thoracic, 147 (22%). The adjuncts cerebrospinal fluid drainage and distal aortic perfusion were used in 428 cases (65%). RESULTS: Thirty-day mortality was 14% (94 of 654). The in-hospital mortality was 16% (106 of 654). Early neurologic deficits occurred in 33 patients (5.0%). Overall, 14 of 428 (3.3%) neurologic deficits were observed in the adjunct group, and 19 of 226 (8.4%) in the nonadjunct group (p = 0.004). When the adjuncts were used during extent II repair, the incidence was 10 of 129 (7.8%) compared with 11 of 36 (30.6%) in the nonadjunct group (p < 0.001). Multivariate analysis demonstrated that risk factors for neurologic deficit were cerebrovascular disease and extent of TAAA (II and III) (p < 0.05). CONCLUSIONS: The combined adjuncts of distal aortic perfusion and cerebrospinal fluid drainage demonstrated improved neurologic outcome with repair of thoracic and TAAAs. In extent II aneurysms, adjuncts continue to make a considerable difference in the outcome and to provide significant protection against spinal cord morbidity. Future research should focus on spinal cord protection in patients with high-risk extent II aneurysms.

Hemodynamic changes and right heart support during vertical displacement of the beating heart.

BACKGROUND: Hemodynamic instability during heart displacement in off-pump multivessel coronary artery bypass grafting might be related to right heart dysfunction. The Enabler (HemoDynamics Systems Ltd, Upper Yoqneam, Israel) is a cannula pump that expels blood from the right atrium into the pulmonary artery. We studied the hemodynamic changes and the role of the enabler during heart displacement. METHODS: Nine anesthetized sheep were assessed for hemodynamic changes during 90-degree heart displacement with or without Enabler support. Hemodynamic parameters included cardiac output, systemic arterial blood pressures, and left and right heart filling pressures. RESULTS: Heart displacement caused a significant decrease in cardiac output and systemic blood pressure (46%+/-5%, p = 0.001; and 20%+/-5%, p = 0.009, respectively), with a concomitant 137%+/-24% (p = 0.003) increase in central venous pressure. No significant change in left atrial pressure was observed. Activation of the Enabler caused a significant increase in cardiac output and systemic blood pressure (67%+/-15%, p = 0.01; and 17%+/-7%, p = 0.04, respectively), as well as a decrease in central venous pressure by 49%+/-8% (p = 0.0001). CONCLUSIONS: Heart displacement causes hemodynamic instability mainly by right heart dysfunction. The Enabler significantly stabilized circulation during vertical displacement of the beating heart.

Same-day combined coronary angioplasty and minimally invasive coronary surgery.

Integrated myocardial revascularization combines the advantages of angioplasty, stenting, and minimally invasive surgery to revascularize patients with multivessel coronary artery disease without cardiopulmonary bypass. This pilot study showed that a new same-day management strategy, consisting of percutaneous coronary intervention followed immediately by minimally invasive surgery, was feasible and provided complete all-arterial revascularization with minimal surgical trauma, short hospital stay, and excellent early therapeutic result in 14 patients with multivessel coronary disease.

The intra-aortic cannula pump: A novel assist device for the acutely failing heart.

OBJECTIVE: The intra-aortic cannula pump is a catheter pump designed to support the acutely failing heart. It expels blood from the left ventricle into the ascending aorta in a pulsatile flow pattern. The aim of the study was to analyze the hemodynamic performance of this new intracardiac support system in acute heart failure. METHODS: A 24F cannula was studied in a series of 16 sheep. Hemodynamic changes were assessed in the nonfailing, the moderately failing, and the severely failing heart. Heart failure was induced by an injection of microspheres into the left anterior descending coronary artery. The cannula was inserted through the aortic arch and introduced through the aortic valve into the left ventricle. RESULTS: Cannula insertion was feasible in all animals. Flow through the intra-aortic cannula flow was increased to a maximum of 3 L/min. No hemodynamic changes were observed in the nonfailing heart. A significant increase in cardiac output was observed in the moderately and severely reduced left ventricle (2.67 +/- 0.7 L to 3.51 +/- 0.83 L; P =.001; and 1.18 +/- 0.77 L to 2.43 +/- 0.44 L; P =.001, respectively). A drop in left atrial pressure was achieved in moderate and severe heart failure (14.1 +/- 5.93 mm Hg to 9.71 +/- 2.63 mm Hg; P =.0001; and 23 +/- 7.16 mm Hg to 11.2 +/- 2.55 mm Hg; P = 0.0001, respectively). Systolic and diastolic systemic blood pressures increased in the severely failing heart (57.3 +/- 12.8 mm Hg to 75.4 +/- 11.2 mm Hg; P =.0001; and 35.6 +/- 8.2 mm Hg to 60 +/- 14.3 mm Hg; P =.0006, respectively). CONCLUSIONS: Hemodynamic data demonstrate the beneficial effects of the intra-aortic cannula pump in moderate and severe heart failure. The intra-aortic cannula pump represents a new modality for the treatment of acute heart failure.

Utility of spiral CT in minimally invasive approach for aortic valve replacement.

OBJECTIVE: Several surgical approaches exist for a minimally invasive replacement of the aortic valve. A great concern exists about the variable exposure of the aortic root. We suggest the use of spiral CT as a non-invasive method for accurate determination of aortic annulus position. METHODS: Three patients scheduled for minimally invasive aortic valve replacement underwent chest spiral CT, (Select SP, Elscint, Haifa, Israel). Scanning was performed during breath holding using 5-mm thick slices, reconstructed every 2 mm (3 mm overlap), and a 1.5 pitch. Average scanning time was 30 s. No intravenous contrast media was used. Multiplannar and 3D images were reconstructed, using an Omnipro work station (Elscint LTD, Haifa, Israel). The position of the aortic valve annulus, in relation to the anterior chest wall was defined on these images. RESULTS: In all patients, the length and location of the incision were determined by the preoperative measurements. The location of the aortic valve was found highly correlative to the preliminary study. There was no need to extend the length of the incision, or change the surgical approach. CONCLUSIONS: We find spiral CT scanning enables accurate pre-operative anatomical assessment. This assessment, provides the surgeon with the advantage of preliminary planning of the appropriate approach for minimally invasive aortic valve replacement.

Using a video conference to teach clinical clerks in a one-week cardiothoracic clerkship.

BACKGROUND: Students report that their operating room experience during specialty clerkships has been less than satisfactory. To deal with this and other problems in a 1-week cardiothoracic clerkship, a video conference system was introduced. METHODS: Three teaching strategies were used: a seminar dealing with the disease process and a description of the operative procedure; bedside pre-operative assessment of the patient, with a tutor; and a live video conference of the operation. The tutor observed the live video presentation with the students, initiating interaction with the operating surgeon and facilitating questions and discussion. Video quality was maintained by one camera connected to the headlight of the surgeon and another placed above the operative field. RESULTS: Both students and staff expressed a high degree of satisfaction in debriefing sessions and on a standard faculty evaluation form. CONCLUSIONS: This innovation in surgery specialty teaching contributes to the acquisition of educational objectives in the operating room and in a cardiothoracic clerkship.

Still's disease associated with adenovirus infection and defect in adenovirus directed natural killing.

Low natural killer (NK) activity towards adenovirus infected fibroblasts was detected in the peripheral blood of a child with Still's disease and was not normalised by the addition of interferon alfa or interleukin 2. NK cytotoxicity directed at K 562 target cells or polio infected fibroblasts was normal. This specific NK deficiency might have contributed to the development of the child's Still's disease.