Viscosity/temperature relationships for dilute solutions of poly(2,4,5-trichlorophenyl methacrylate)

The actual viscosity η of six fractions of poly(2,4,5-trichlorophenyl methacrylate) (PTCPh) with weight-average molecular weight M?_w, ranging from 9,11 · 10⁴ to 94,8 · 10⁴, was determined in benzene at a number of temperatures from 22 to 60°C. The variation of the pre-exponential term A and the apparent activation energy of viscous flow Q, with molecular weight and concentration was studied. Moore's equations are valid for PTCPh. The temperature coefficient of the unperturbed dimensions dln 〈r²₀〉/dT estimated from the intrinsic viscosity data by using the Burchard-Stockmayer-Fixman relation, is ?3 . 10^-3 (from 22 to 40°C) and ?0,87 . 10^-3 (from 40 to 60°C). These negative values indicate that extended configurations of PTCPh in benzene must be associated with lower energies.     

Regional myocardial motion and thickening assessed at rest by ECG-gated99mTc-MIBI emission tomography and by magnetic resonance imaging

We have validated ECG-gated emission tomography using technetium-99m methoxyisobutylisonitrile for the assessment of regional ventricular function by comparing it with cine magnetic resonance imaging (MRI). Gated tomography was performed at rest in 24 patients referred for myocardial perfusion imaging [17 males and seven females with a mean age of 58 years, nine of whom had had a previous myocardial infarction (MI)]. Scores were assigned to each of nine myocardial segments for wall motion and for thickening. Cine MRI was analysed in an identical fashion. Four out of 216 (2%) segments were uninterpretable by gated tomography because of inadequate tracer uptake. In eight patients without coronary artery disease (CAD), wall motion and thickening were normal by both methods. Gated tomography showed abnormal wall motion or thickening in all patients with previous MI and in five of seven patients with CAD but no prior MI. Association between wall motion and thickening was good (r _s=0.86). Overall, there was good agreement between gated tomography and MRI for both wall motion (178/212 segments, =0.66) and wall thickening (184/212 segments, =0.69). In segments with severely reduced perfusion, however, there was poorer agreement (=0.31). Interobserver and intraobserver agreement was high ( from 0.61 to 0.78). Thus, in patients investigated for CAD, there is good overall agreement between gated tomography and MRI but the agreement is lower in segments with severe perfusion defects.     

Cisplatin plus etoposide chemotherapy followed by thoracic irradiation and paclitaxel plus cisplatin consolidation therapy for patients with limited stage small cell lung carcinoma

PURPOSE: To evaluate the efficacy and tolerance of a cisplatin plus etoposide regimen followed by thoracic radiotherapy (TRT) and paclitaxel plus cisplatin consolidation chemotherapy in patients with limited stage small cell lung cancer (SCLC). PATIENTS AND METHODS: Thirty-nine patients with limited SCLC were enrolled onto this study. Patients received three courses of cisplatin 75 mg/m2 i.v., day 1 and etoposide 100 mg/m2 i.v., days 1-3 (EP regimen), followed by TRT (45-56 Gy administered in 15 fractions), and three courses of paclitaxel 175 mg/m2 i.v., day 1 and cisplatin, as previously, on day 2 (PP regimen); cycles were repeated every 21 days. RESULTS: All patients were evaluable for toxicity and 34 for response. The overall response rate was 67% (CR: 26%; PR: 41%; intention-to-treat analysis) (95% CI: 53.0-84.2%). After a median follow-up period of 15 months, the median survival time was 15 months, the median time to tumor progression 8.3 months and the 1-year survival rate 53.8%. Grade 3/4 neutropenia occurred in 39% and 36% of patients receiving EP and PP regimens, respectively. The incidence of febrile neutropenia was 5% and 3% for EP and PP regimens, respectively. Other hematologic and non-hematologic toxicities were mild, with the exception of esophagitis occurring in 36% of patients during and/or immediately after radiotherapy. CONCLUSION: Consolidation therapy with PP after sequential EP and thoracic radiotherapy is feasible and well-tolerated; however, the efficacy results are comparable with those previously obtained in the same patients' population using a combination of EP and TRT.     

Endothelin-aldosterone interaction and proteinuria in low-renin hypertension

OBJECTIVE: To investigate whether endothelin and aldosterone participate in the increased prevalence and severity of nephrosclerosis in human low-renin hypertension, analogous to observations in experimental hypertension. DESIGN: Comparison of endothelin, aldosterone and their relationships with proteinuria, in hypertensive patients with high aldosterone : renin ratios (HARR group, n = 14) or normal aldosterone : renin ratios (NARR group, n = 15). METHODS: Urine protein and radioimmunoassay measurements of plasma renin activity, endothelin and aldosterone were carried out in individuals taking their usual diet, and after salt loading and salt depletion. RESULTS: Compared with the NARR group, patients in the HARR group had higher blood pressure, greater salt sensitivity of their blood pressure, significantly greater urine protein and lower serum potassium concentrations, lower renin activities [0.14 +/- 0.03 ng AngiotensinI (AI)/l per s compared with 0.76 +/- 0.16 ng AI/l per s; P < 0.005], blunted renin-aldosterone responses to salt loading and salt depletion, enhanced catecholamine responses to salt depletion, and increased plasma endothelin (5.1 +/- 0.5 fmol/ml compared with 3.7 +/- 0.3 fmol/ml; P < 0.03). In the HARR group, endothelin and aldosterone concentrations were highly correlated, and both correlated with blood pressure and urine protein. In contrast, in the NARR group, endothelin and aldosterone did not correlate between them or with blood pressure, and only endothelin, not aldosterone, correlated with urine protein. Multivariate regression confirmed that the interaction between aldosterone and endothelin was the major predictor of urine protein in the HARR group (r = 0.442), whereas endothelin, renin and their interaction were predictors in the NARR group (r = 0.467). CONCLUSIONS: Our results concur with experimental evidence for participation of endothelin in renal damage of angiotensin-dependent hypertension and for that of an endothelin-aldosterone interaction in low-renin hypertension. We propose that combined pharmacological antagonism of endothelin and aldosterone may confer renal protection beyond blood pressure reduction in patients with low-renin hypertension, a population at high risk for hypertensive nephrosclerosis.     

Management of Intra-Aortic Balloon Pump Entrapment: A Case Report and Review of the Literature

An intra-aortic balloon pump is one of the most valuable tools in the cardiac surgeon''s armament to assist in the management of the failing heart. Despite its widespread use, there are associated risks and complications, one of which is balloon rupture with associated entrapment. Numerous approaches for dealing with this complication have been described; here we review the previous experience with intra-aortic balloon pump entrapment and discuss potential management, with particular reference to a recent case of our own.Key words: Assisted circulation/adverse effects, counterpulsation/mortality, entrapment, intra-aortic balloon pumping/adverse effects/methods/mortality/rupture/standards/statistics & numerical data, risk assessmentCardiac surgery offers myriad interventions for possible use in an aging population that has a high prevalence of heart disease. This abundance of options has led to more complex cardiac surgery and to higher public expectations of successful outcomes.¹ Against this background, any mechanism that facilitates survival is welcome.The intra-aortic balloon pump (IABP), first used by Kantrowitz in 1967 in a patient with cardiogenic shock, provides mechanical cardiac support via insertion of an inflatable balloon into the descending aorta; it is the most commonly used supportive tool for temporary cardiac assistance.^1,2 The IABP works by reducing afterload and actively increasing coronary perfusion.² The indications are varied but include ongoing ischemia refractory to medical therapy, a need for prophylaxis in high-risk patients before cardiac surgery, and postoperative ischemia and low cardiac output despite inotropic support.³ Intra-aortic balloon pump use, although priceless in improving postoperative survival in high-risk cardiac surgical patients and those with ventricular dysfunction, is not without risks.^1,2 Balloon rupture, aortic or iliac artery dissection, thromboembolism, distal ischemia, and thrombocytopenia due to the mechanical action of the balloon on platelets are all potential complications of IABP use.^1,4 Despite these risks, there are over 70,000 insertions annually in the United States alone. Of all cardiac surgical patients, 5% to 10% undergo IABP placement.⁵ Intra-aortic balloon pump rupture with associated entrapment of the balloon within the arterial tree is very rare. Because numerous approaches to deal with this complication have been described, we review the previous experience and discuss the potential management of IABP entrapment, with specific reference to a case of our own.     

Aortic balloon valvuloplasty before transcatheter valve replacement in high-risk patients with aortic stenosis

Background

Balloon aortic valvuloplasty (BAV) has been revived as a bridge to transcatheter aortic valve replacement (TAVR). The aim of the current prospective study was to define a safe time period from BAV to TAVR and to determine hemodynamic variables that predict event-free survival after BAV.

Patients and methods

The present prospective study included 68 consecutive patients with severe aortic stenosis who were treated initially with BAV from 2009 to 2012. Echocardiographic and invasive hemodynamic assessments were performed before BAV. The patients were followed up at regular intervals and events were defined as cardiac hospitalization or death.

Results

Invasive hemodynamic evaluation yielded more favorable results than echocardiographic assessment: aortic stenosis was less severe, cardiac output was higher, and pulmonary capillary wedge pressure (PCWP) was lower. Post-BAV event-free survival was 80.4?% at 30 days, 64.5?% at 6 months, 37?% at 1 year, 22.3?% at 2 years, and 9.3?% at 3 years. After excluding pre-discharge deaths (n?=?7), the 30-day event-free survival rate was 90?%. Predictors of events after BAV were atrial fibrillation, cardiogenic shock, elevated euroSCORE (European System for Cardiac Operative Risk Evaluation), elevated PCWP, and elevated pulmonary artery systolic pressure. Invasively measured PCWP was the only independent predictor of events (hazard ratio, 1.07; 95?% confidence interval, 1.03–1.11; p?=?0.001).

Conclusion

A 30-day post-BAV period may be considered a bridge to TAVR. Furthermore, invasive assessment of PCWP before BAV is an independent hemodynamic predictor of events after BAV.

     

Efficacy and safety of high dose versus low dose furosemide with or without dopamine infusion: The Dopamine in Acute Decompensated Heart Failure II (DAD-HF II) Trial

Aims

The role of low-dose dopamine infusion in patients with acute decompensated heart failure (ADHF) remains controversial. We aim to evaluate the efficacy and safety of high- versus low-dose furosemide with or without low-dose dopamine infusion in this patient population.

Methods and results

161 ADHF patients (78 years; 46% female; ejection fraction 31%) were randomized to 8-hour continuous infusions of: a) high-dose furosemide (HDF, n = 50, 20 mg/h), b) low-dose furosemide and low-dose dopamine (LDFD, n = 56, 5 mg/h and 5 μg kg^− 1 min^− 1 respectively), or c) low-dose furosemide (LDF, n = 55, furosemide 5 mg/h). The main outcomes were 60-day and one-year all-cause mortality (ACM) and hospitalization for HF (HHF). Dyspnea relief (Borg index), worsening renal function (WRF, rise in serum creatinine (sCr) ≥ 0.3 mg/dL), and length of stay (LOS) were also assessed. The urinary output at 2, 4, 6, 8, and 24 h was not significantly different in the three groups. Neither the ACM at day 60 (4.0%, 7.1%, and 7.2%; P = 0.74) or at one year (38.1%, 33.9% and 32.7%, P = 0.84) nor the HHF at day 60 (22.0%, 21.4%, and 14.5%, P = 0.55) or one year (60.0%, 50.0%, and 47%, P = 0.40) differed between HDF, LDFD, and LDF groups, respectively. No differences in the Borg index or LOS were noted. WRF was higher in the HDF than in LDFD and LDF groups at day 1 (24% vs. 11% vs. 7%, P < 0.0001) but not at sCr peak (44% vs. 38% vs. 29%, P = 0.27). No significant differences in adverse events were noted.

Conclusions

In ADHF patients, there were no significant differences in the in-hospital and post-discharge outcomes between high- vs. low-dose furosemide infusion; the addition of low-dose dopamine infusion was not associated with any beneficial effects.