Valganciclovir Dosing According to Body Surface Area and Renal Function in Pediatric Solid Organ Transplant Recipients

Oral valganciclovir is effective prophylaxis for cytomegalovirus (CMV) disease in adults receiving solid organ transplantation (SOT). However, data in pediatrics are limited. This study evaluated the pharmacokinetics and safety of valganciclovir oral solution or tablets in 63 pediatric SOT recipients at risk of CMV disease, including 17 recipients ≤2 years old. Patients received up to 100 days' valganciclovir prophylaxis; dosage was calculated using the algorithm: dose (mg) = 7 × body surface area × creatinine clearance (Schwartz method; CrCLS). Ganciclovir pharmacokinetics were described using a population pharmacokinetic approach. Safety endpoints were measured up to week 26. Mean estimated ganciclovir exposures showed no clear relationship to either body size or renal function, indicating that the dosing algorithm adequately accounted for both these variables. Mean ganciclovir exposures, across age groups and organ recipient groups were: kidney 51.8 ± 11.9 μg * h/mL; liver 61.7 ± 29.5 μg * h/mL; heart 58.0 ± 21.8 μg * h/mL. Treatment was well tolerated, with a safety profile similar to that in adults. Seven serious treatment-related adverse events (AEs) occurred in five patients. Two patients had CMV viremia during treatment but none experienced CMV disease. In conclusion, a valganciclovir-dosing algorithm that adjusted for body surface area and renal function provides ganciclovir exposures similar to those established as safe and effective in adults     

Risk of thrombosis during coronary angioplasty with low osmolality contrast media

Studies in vitro have suggested that nonionic low osmolar contrast agents produce an increase in thrombogenicity. To determine the incidence of thrombi related to the use of nonionic low osmolar contrast media during coronary angioplasty, a double-blind randomized study was performed in 100 patients. Medication before angioplasty included oral aspirin (250 mg/day) in all cases. At the beginning of the procedure, aspirin (250 mg) and heparin (10,000 U) were intravenously administered. During the procedure patients were randomly assigned to receive either an ionic low osmolar contrast agent ioxaglate (n = 50), or a nonionic low osmolar contrast media iohexol (n = 50). The presence of thrombus was evaluated on the angiogram and on the guidewire immediately after its retrieval from the patients. Clinical, angiographic and procedural variables were similar in the 2 randomized groups. Angiographic evidence of thrombus was observed in 1 patient (2%) assigned to ioxaglate and in 11 patients (22%) assigned to iohexol (p less than 0.005). One patient (2%) from the ioxaglate group and 6 patients (12%) from the iohexol group showed thrombotic residues on the guidewire (p = not significant). Three patients had acute myocardial infarction, 1 patient (2%) receiving ioxaglate and 2 patients (4%) iohexol (p = not significant). There were no deaths. Thus, compared with an ionic low osmolar contrast media ioxaglate, the nonionic low osmolar contrast agent iohexol increases the incidence of thrombus during coronary angioplasty.     

Culture-independent species typing of neotropical Leishmania for clinical validation of a PCR-based assay targeting heat shock protein 70 genes

PCR-restriction fragment length polymorphism analysis of heat shock protein 70 genes discriminates most neotropical Leishmania species, as well as Trypanosoma cruzi. The assay, combined with capillary electrophoresis in a microchip device, may be applied directly on clinical samples with a high sensitivity, hence supporting clinical and epidemiological monitoring of leishmaniasis.     

Human natural killer cell lysis of Salmonella typhi intracellularly-infected U937 cells

Peripheral blood mononuclear cell (PBMC) cytotoxicity against S. typhi (wild type or mutant strain TYT1231)-infected U937 cells was significantly higher than its lytic effect against noninfected cells (control) at the various effector-to-target cell ratio used (30:1, 50:1 and 70:1). Natural killer cell activity [expressed as % specific lysis (mean +/- SEM); 30:1 (25.4 +/- 3.6, 25.1 +/- 4.2 and 16.3 +/- 3.3); 50:1 (27.8 +/- 3.7, 26.7 +/- 4.5 and 20.9 +/- 2.9) and 70:1 ratio (33.2 +/- 5.9, 29.4 +/- 4.2 and 22.8 +/- 2.8), respectively] appeared to be dependent on such ratios and independent of the S strain studied. Most (80%) of individual samples tested showed at least a 20% specific lysis increase over their own control; essentially no changes or smaller increases in NKC activity were observed in all other samples. Similar results were obtained when using highly purified NKC (HPNKC) preparations as effector cells [NKC activity (mean +/- SEM); 5:1 (46.2 +/- 4.7, 43.2 +/- 5.0 and 25.2 +/- 2.3) and 10:1 effector-to-target cell ratio (49.3 +/- 4.9, 44.7 +/- 5.2 and 27.2 +/- 2.6, respectively)]. All individual samples tested showed at least a 20% specific lysis increase over their own control. These results show that S. typhi-infected U937 cells are a significantly better target for NKCs than control cells and indicate that intracellular bacteria survival capacity is not a critical factor for infected cells becoming a NKC target.     

Chile's health sector reform: lessons from four reform periods

This paper applies an interdisciplinary approach to analyze the process of health reform in four significant periods in Chilean history: (1) the consolidation of state responsibility for public health in the 1920s, (2) the creation of the state-run National Health Service in the 1950s, (3) the decentralization of primary care and privatization of health insurance in the 1980s, and (4) the strengthening of the mixed public-private market in the 1990s. Building on the authors' separate disciplines, the paper examines the epidemiological, political and economic contexts of these reforms to test simple hypotheses about how these factors shape reform adoption and implementation. The analysis underlines: (1) the importance of epidemiological data as an impetus to public policy; (2) the inhibiting role of economic recession in adoption and implementation of reforms: and (3) the importance of the congruence of reforms with underlying political ideology in civil society. The paper also tests several hypotheses about the reform processes themselves, exploring the role of antecedents, interest groups, and consensus-building in the policy process. It found that incremental processes building on antecedent trends characterize most reform efforts. However, interest group politics and consensus building were found to be complex processes that are not easily captured by the simple hypotheses that were tested. The interdisciplinary approach is found to be a promising form of analysis and suggests further theoretical and empirical issues to be explored.     

Clinical features of hepatic artery thrombosis after pediatric liver transplantation

Thrombosis of the hepatic artery (HAT) is a severe complication of liver transplantation, and most cases need regrafting. The aim of this study was to review our experience with this complication. From January 1986 through January 1992, 76 liver transplants were performed in 59 pediatric patients at the Children's Hospital La Paz, Madrid. The diagnosis of HAT was made in 12 cases (15.7%). The common patterns of clinical presentation were: fulminant liver necrosis (5), bile leak due to necrosis of the bile duct (4), and relapsing bacteremia (3). Clinical symptoms of fulminant liver necrosis started within the first 2 weeks after transplantation, with rapid deterioration and steep rises in SGOT and SGPT levels. All these patients were retransplanted on an urgent basis, but only 1 is alive 4 years later. Four patients developed bile leaks 13 to 60 days after transplantation; SGOT, SGPT, and total bilirubin were only slightly increased. Three children were retransplanted electively and are alive with a mean follow-up of 3 years. One exceptional patient had a Roux-en-Y jejunostomy and is doing well 30 months later with his original graft. The 3 remaining children had episodes of septicemia with hepatic abscess, liver infarction, and pleural effusion. Liver function tests were normal, with bilirubin levels below 2 mg/dl. All patients were retransplanted, but only 1 is alive and well 13 months later. In the present series, we found that early HAT produces fulminant clinical deterioration requiring an urgent regraft. Late HAT presenting with either infection or bile leak allows time for treatment by elective retransplantation. The best survival was obtained in the latter group. Correspondence to: J. Vázquez     

Superiority of magnesium cardioplegia in neonatal myocardial protection

Background. We have shown that magnesium can offset the detrimental effects of normocalcemic cardioplegia in hypoxic neonatal hearts. It is not known, however, whether magnesium offers any additional benefit when used in conjunction with hypocalcemic cardioplegia.

Methods. Twenty neonatal piglets underwent 60 minutes of ventilator hypoxia (FiO₂ 8% to 10%) followed by 20 minutes of normothermic ischemia on cardiopulmonary bypass (hypoxic-ischemic stress). They then underwent 70 minutes of multidose blood cardioplegic arrest. Five (Group 1), received a hypocalcemic (Ca⁺² 0.2 to 0.4 mM/L) cardiologic solution without magnesium, whereas in 10, magnesium was added at either a low dose (5 to 6 mEq/L, Group 2) or high dose (10 to 12 mEq/L, Group 3). In the last 5 (Group 4), magnesium (10 to 12 mEq/L) was added to a normocalcemic cardioplegic solution. Function was assessed using pressure volume loops and expressed as percentage of control.

Results. Compared to hypocalcemia cardioplegic solution without magnesium (Group 1), both high- and low-dose magnesium enrichment (Groups 2 and 3) improved myocardial protection resulting in complete return of systolic (40% vs 101% vs 102%) (p < 0.001 vs Groups 2 and 3) and global myocardial function (39% vs 102% vs 101%) (p < 0.001 vs Groups 2 and 3), and reduced diastolic stiffness (267% vs 158% vs 154%) (p < 0.001 vs Groups 2 and 3). Conversely, even high-dose magnesium supplementation could not offset the detrimental effects of normocalcemic cardioplegia resulting in depressed systolic (End Systolic Elastance [EES] 41% ± 1%) (p < 0.001 vs Groups 2 and 3) and global myocardial function (40% ± 1%) (p < 0.001 vs Groups 2 and 3), and a marked rise in diastolic stiffness (258% ± 5%) (p < 0.001 vs Groups 2 and 3). Hypocalcemic magnesium cardioplegia has now been used successfully in 247 adult and pediatric patients.

Conclusions. Magnesium enrichment of hypocalcemic cardioplegic solutions improves myocardial protection resulting in complete functional preservation. However, magnesium cannot prevent the detrimental effects of normocalcemic cardioplegia when the heart is severely stressed. This study, therefore, strongly supports using both a hypocalcemic cardioplegic solution and magnesium supplementation as their benefits are additive.     

Use of three-dimensional MR angiography for tracking a contrast bolus in the carotid artery

Contrast-bolus tracking in the carotid bifurcation was accomplished using an MR angiographic technique with a 3D turbo field-echo readout (TR/TE = 6/3, flip angle = 50 degrees) modified by a keyhole scheme. Optimal visibility of the contrast bolus was achieved by digital subtraction from a reference volume. This technique reliably time-resolves the carotid arteries from the jugular veins.     

Pathophysiology of cardiac extracorporeal membrane oxygenation

The treatment of cardiogenic shock using inotropic agents and vascular volume expansion places an added burden on the heart. The resultant increase in cardiac work may cause myocardial ischemia and lead to cardiac arrest. Extracorporeal membrane oxygenation (ECMO) may be used to treat cardiogenic shock. It supports systemic circulation, assures diastolic perfusion of the myocardium, and reduces cardiac workload. The rise in blood pressure associated with restoring systemic circulation afterloads the heart and can cause left atrial hypertension and pulmonary edema. ECMO does not automatically reduce cardiac work, especially in the presence of residual shunts. Left atrial drainage or decompression may be essential in certain patients both to avert pulmonary edema and to reduce cardiac work.     

Tolerabilidad y efectividad del citrato de fentanilo oral transmucosa en el tratamiento a largo plazo del dolor irruptivo en pacientes oncológicos: estudio ECODIR

INTRODUCTION: Oral trans-mucosal fentanyl citrate (OTFC) is the one drug specifically developed for the management of breakthrough pain. This study assesses the long-term safety and efficacy of OTFC standard clinical conditions. Patients and methods. Six-month observational study performed on cancer patients with episodes of breakthrough pain. Safety was assessed by recording the advent of adverse events and efficacy by the evaluating the intensity of breakthrough pain. RESULTS: 174 cancer patients were recruited into the study. All adverse reactions reported were mild or moderate. OTFC was significantly faster (time to the commencement of pain relief: 12.7 +/- 11.4 vs 32.7 +/- 18.4 minutes; p < 0.001) and potent (post-treatment pain intensity: 3.4 +/- 1.5 vs 4.3 +/- 1.5; p < 0.001) than the previously-used drugs. CONCLUSIONS: This observational study confirms the good safety profile of OTFC as well as its effectiveness over long-term period treatment of breakthrough pain.