Iron‐loaded PLLA nanoparticles as highly efficient intracellular markers for visualization of mesenchymal stromal cells by MRI

Monitoring of the fate of cells after injection appears paramount for the further development of cell therapies. In this context magnetic resonance imaging (MRI) is increasing in relevance owing to its unique tissue visualization properties. For assessment of cell trafficking and homing, the cells have to be labeled to become MR visible. The rather low sensitivity of MRI demands dedicated intracellular markers with high payloads of MR contrast agents for ensuring sensitive detection of local cell aggregations. In the presented work the application of custom‐designed nanometer‐sized iron oxide loaded poly‐(l ‐lactide) (iPLLA) nanoparticles was investigated. The particles were synthesized by the mini‐emulsion process and evaluated for labeling of mesenchymal stromal cells (MSCs). The efficient cellular uptake and long intracellular retention times of the particles as well as their nontoxicity are demonstrated. The average cellular iron content was 55 pg iron per cell. Further incorporation of, for example, fluorescent dye enables the generation of multireporter particles, providing the great potential for multimodal imaging. The efficiency of these nanoparticles as MRI contrast agent was evaluated in vitro using relaxation rate mapping, yielding relaxivities r₂ = 273.3, r₂^* = 545.1 mm ^?1 s^?1 at 3 T and r₂ = 415.7, r₂^* = 872.3 mm ^?1 s^?1 at 11.7 T. The high r₂^* relaxivity of the iPLLA nanoparticles enabled visualization of a single labeled cell in vitro at 50‐µm spatial resolution. In vivo evaluation in a rat injury model revealed the potential of the iPLLA particles to efficiently label MSCs for MRI monitoring of ~20 000–40 000 injected cells at 11.7 T. In conclusion the presented work demonstrates the applicability of iPLLA particles as efficient intracellular marker for MSC labeling for monitoring the fate of the cells by MRI. Copyright © 2014 John Wiley & Sons, Ltd.     

Metabolic changes in the lower esophageal sphincter influencing the result of anti-reflux surgical interventions in chronic gastroesophageal reflux disease

AIM: With the availability of a minimally invasive approach, anti-reflux surgery has recently experienced a renaissance as a cost-effective alternative to life-long medical treatment in patients with gastroesophageal reflux disease (GERD). We are not aware of the fact whether reflux episodes causing complaints for a long time i.e., at least for one year are associated with metabolic changes in the lower esophageal sphincter, and if so, whether these may influence functional results achieved after anti-reflux surgery. METHODS: Between 1 January 2001 and 31 December 2002 we performed anti-reflux surgery on 79 patients. Muscle samples were taken from the lower esophageal sphincter (LES) in 33 patients during anti-reflux surgery. Inclusion criteria were: LES resting pressure below 10 mmHg and a marked, pH proven acid exposure to the esophagus of at least one year's duration, causing subjective complaints and requiring continuous proton pump inhibitor treatment. Control samples were obtained from muscle tissue in the gastroesophageal junction that had been removed from 17 patients undergoing gastric or esophageal resection. Metabolic and lysosomal enzyme activities and special protein concentrations 16 parameters in total were evaluated in tissue taken from control specimens and tissue taken from patients with GERD. The biochemical parameters of these intra-operative biopsies were used to correlate the results of anti-reflux operations (Visick Ⅰ and Ⅱ-Ⅲ). RESULTS: In the reflux-type muscle, we found a significant increase of the energy-enzyme activities e.g., creatine kinase, lactate dehydrogenase, β-hydroxybutyrate dehydrogenase, and aspartate aminotransaminase-. The concentration of the structural protein S-100 and the myofibrillar protein troponin Ⅰ were also significantly increased. Among lysosomal enzymes, we found that the activities of cathepsin B, tripeptidyl-peptidase Ⅰ, dipeptidyl-peptidase Ⅱ, β-hexosaminidase B, β-mannosidase and β-galactosidase were significantly decreased as compared to the control LES muscles. By analyzing the activity values of the 9 patients in Visick groups Ⅱ and Ⅲ at two months post-surgery, we found a significant increase in the activity of the so-called energy-enzyme values and in the concentration of structural and myofibrillar proteins as compared to the rest of the reflux patients. CONCLUSION: Our results call attention to the metabolic changes that occurred in the LES muscles of reflux patients. The developing hypertrophy-like changes of LES muscles may be a reason for complaints after anti-reflux surgery, which consisted mainly of reports of persisting dysphagia.     

Infections associated with ventricular assist devices: epidemiology and effect on prognosis after transplantation

BACKGROUND: Ventricular assist devices (VADs) can be used as a bridge to orthotopic heart transplantation (OHT) in people with severe congestive heart failure. Although they can be inserted for an indefinite time period (unlike balloon pumps), they do carry a substantial risk of infection. We studied the epidemiology, microbiology, and consequences of infection in patients with VADs who ultimately had cardiac transplantation. METHODS: Records of VAD-supported patients at our institution between January 1995 and January 2005 were identified by ICD-9 code. Infection was classified as driveline infection, pocket infection, mediastinitis, or VAD endocarditis in increasing severity of illness. RESULTS: Of 73 patients identified by ICD-9 code, 60 had charts available for review. Of these 60, 72% had a VAD infection: 13 had VAD endocarditis; 3, mediastinitis; 25, pocket infection; and 29, driveline infection. The only association of infection (43 patients, 72%) and demography or underlying disease was that of endocarditis with older age (median age 59 vs. 53 years; P=0.02) and diabetes mellitus (13 patients, 30%; risk ratio 3.4; P=0.01). The duration of VAD support was longer in infected patients (median 125 days) vs. uninfected ones (25 days). Median survival measured from the time of VAD placement (although also true from the time of transplantation) was shorter in patients with VAD endocarditis (120 days) and pocket infection (350 days) vs. no infection (>2400 days) with a significant P=0.017 for endocarditis. Four patients had infections after transplantation that were caused by the same organism as their VAD infection. The predominant pathogens in VAD infection were Staphylococcus and Enterococcus spp. CONCLUSION: VAD use as a bridge to cardiac transplantation is associated with a large number of device-related infections. Patients with infected VADs, on average, wait longer for transplantation than patients with uninfected VADs, and patients with VAD endocarditis have a shorter survival than patients with no VAD infection or simple driveline infection.     

9-(2-膦酰甲氧乙基)腺嘌呤及其位置异构体3-(2-膦酰甲氧乙基)腺嘌呤的合成和抗病毒活性研究

Phosphonylmethoxyethyl)adenine (1),PMEA,an acyclic nucleotide withbroad-spectrum antiviral activity was synthesized with some modifications of Holy's procedure.Simutaneously,an N-3 regioisomer(2)of PMEA and a by-preduct, formaldehyde di-[2-(9-adenyl)ethyl] acetal(7)were seperated by silica gel chromatography in the ratio of 50:10:1.Compound(2)and(7) are new compounds that we have not yet found in literatures. The structure of them weredetermined with ¹HNMR,2DNMR, MS and Spot test.Antiviral test showed that N-3 isomer(2)completely lost activity against both HIV-1 and HSV-1 in vitro. It seems that regiospecificity of theacyclic nucleotide structure is important for antiviral activity.     

Plasma lipid and apolipoprotein concentrations in full term infants fed formula supplemented with long-chain polyunsaturated fatty acids and cholesterol

Recent data indicate that supplementation of infant formula with ω-3 and ω-6 long-chain polyunsaturated fatty acids might offer developmental benefits for full term infants. We investigated biochemical consequences of feeding formula supplemented with egg lipids to provide long-chain polyunsaturated fatty acids and compared triglyceride, cholesterol, lipoprotein cholesterol (HDL₂-cholesterol, HDL₃-cholesterol, non-HDL-cholesterol) and apolipoprotein A-I, A-II and B concentrations in full term infants fed either conventional formula (n = 10) or a formula supplemented with ω-3 and ω-6 long-chain polyunsaturated fatty acids and cholesterol in amounts similar to those found in mature human milk (n = 12). At the age of 5 days, cholesterol, non-HDL-cholesterol and triglyceride concentrations were significantly higher in infants fed supplemented than in those receiving conventional formula. At the age of 30 days, triglyceride concentrations were significantly higher with supplemented than with conventional formula. Thereafter throughout the study, no significant differences were seen between the two groups. Conclusion Full term infants fed formula supplemented with ω-3 and ω-6 long-chain polyunsaturated fatty acids and cholesterol showed significantly higher plasma cholesterol and triglyceride concentrations than infants receiving conventional formula on day 5 and on days 5 and 30, respectively. Thereafter no appreciable effect of diet on plasma phospholipid, triglyceride, cholesterol, lipoprotein cholesterol and apolipoprotein concentrations were seen. Received: 13 March 1996 / Accepted: 21 October 1996     

Changing aspects of psychiatric inpatient treatment

This paper presents data obtained in a one-day census investigation in five European countries (Austria, Hungary, Romania, Slovakia, Slovenia). The census forms were filled in for 4191 psychiatric inpatients. Concerning legal status, 11.2% were hospitalised against their will (committed) and 21.4% were treated in a ward with locked doors. There was only a small correlation between commitment and treatment in a locked ward. More frequent than treatment of committed patients in locked wards was treatment of committed patients in open wards (Austria, Hungary) and treatment of voluntary patients in closed wards (Slovakia, Slovenia). Concerning employment, 27.7% of patients aged 18-60 held a job before admission. The vast majority of patients (84.8%) had a length of stay of less than 3 months. A comparison of these data with the results of a study performed in 1996 and using the same method shows a decrease of rates of long-stay patients. In 1996 the rates of employment were significantly higher in Romania (39.3%) and Slovakia (42.5%) compared to Austria (30.7%). These differences disappeared in 1999 due to decreasing rates of employment in Romania and Slovakia. The numbers of mental health personnel varies between types of institution (university or non-university) and countries, being highest in Austria and lowest in Romania. A considerable increase in the numbers of staff was found in Slovakia.     

Angiographic diagnosis of gastric volvulus with report of a complication following left gastric artery embolization

Gastric volvulus is a rare cause of upper gastrointestinal (UGI) tract obstruction and may present as acute UGI hemorrhage. The angiographic findings of gastric volvulus are discussed and a report of a complication of embolization of the left gastric artery in unsuspected mesenteroaxial stomach volvulus is given.     

Ion concentrations in serum and cerebrospinal fluid of patients with neuromuscular diseases

Summary The Na⁺, K⁺, Ca²⁺, Mg²⁺, Cl^–, and P_i concentrations in serum and lumbar CSF of 17 controls and 62 patients with neuromuscular diseases were determined and the values statistically evaluated. Although alterations in ion concentrations specifical to different groups were not observed in either of these biological fluids, the significant increase in serum P_i concentration in Duchenne muscular dystrophy seems to be remarkable. It is suggested that the possible alterations in the ion content of the serum and CSF may contribute additional data to the diagnosis of various neuromuscular diseases.Supported by Ministry of Health, Hungary-/2-20-0303-01-0/M.