1,094 research outputs found
Functional protection by acute phase proteins alpha(1)-acid glycoprotein and alpha(1)-antitrypsin against ischemia/reperfusion injury by preventing apoptosis and inflammation.
BACKGROUND: Ischemia followed by reperfusion (I/R) causes apoptosis, inflammation, and tissue damage leading to organ malfunction. Ischemic preconditioning can protect against such injury. This study investigates the contribution of the acute phase proteins alpha(1)-acid glycoprotein (AGP) and alpha(1)-antitrypsin (AAT) to the protective effect of ischemic preconditioning in the kidney. METHODS AND RESULTS: Exogenous AGP and AAT inhibited apoptosis and inflammation after 45 minutes of renal I/R in a murine model. AGP and AAT administered at reperfusion prevented apoptosis at 2 hours and 24 hours, as evaluated by the presence of internucleosomal DNA cleavage, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling, and the determination of renal caspase-1- and caspase-3-like activity. AGP and AAT exerted anti-inflammatory effects, as reflected by reduced renal tumor necrosis factor-alpha expression and neutrophil influx after 24 hours. In general, these agents improved renal function. Similar effects were observed when AGP and AAT were administered 2 hours after reperfusion but to a lesser extent and without functional improvement. Moreover, I/R elicited an acute phase response, as reflected by elevated serum AGP and serum amyloid P (SAP) levels after 24 hours, and increased hepatic acute phase protein mRNA levels after 18 hours of renal reperfusion. CONCLUSIONS: We propose that the antiapoptotic and anti-inflammatory effects of AGP and AAT contribute to the delayed type of protection associated with ischemic preconditioning and other insults. This mechanism is potentially involved in the course of many clinical conditions associated with I/R injury. Moreover, exogenous administration of these proteins may provide new therapeutic means of treatmen
Type 2 Diabetes Mellitus: New Genetic Insights will Lead to New Therapeutics
Type 2 diabetes is a disorder of dysregulated glucose homeostasis. Normal glucose homeostasis is a complex process involving several interacting mechanisms, such as insulin secretion, insulin sensitivity, glucose production, and glucose uptake. The dysregulation of one or more of these mechanisms due to environmental and/or genetic factors, can lead to a defective glucose homeostasis. Hyperglycemia is managed by augmenting insulin secretion and/or interaction with hepatic glucose production, as well as by decreasing dietary caloric intake and raising glucose metabolism through exercise. Although these interventions can delay disease progression and correct blood glucose levels, they are not able to cure the disease or stop its progression entirely. Better management of type 2 diabetes is sorely needed. Advances in genotyping techniques and the availability of large patient cohorts have made it possible to identify common genetic variants associated with type 2 diabetes through genome-wide association studies (GWAS). So far, genetic variants on 19 loci have been identified. Most of these loci contain or lie close to genes that were not previously linked to diabetes and they may thus harbor targets for new drugs. It is also hoped that further genetic studies will pave the way for predictive genetic screening. The newly discovered type 2 diabetes genes can be classified based on their presumed molecular function, and we discuss the relation between these gene classes and current treatments. We go on to consider whether the new genes provide opportunities for developing alternative drug therapies
Effectiveness of customary use of phytosterol/-stanol enriched margarines on blood cholesterol lowering.
Postlaunch monitoring of functional foods can encompass monitoring of effectiveness under conditions of customary use. To this end, the effectiveness of phytosterol/-stanol enriched margarine consumption in free-living conditions was investigated with data from the Dutch "Doetinchem cohort study". In total, 4,505 subjects (aged 26-70 years) were examined in 1994-1998 and re-examined during 1999-2003. A general and a food frequency questionnaire and non-fasting blood samples for total and HDL cholesterol determination were obtained. Subjects were stratified into phytosterol/-stanol enriched margarine users (n = 84) and non-users (n = 4,421) based on the re-examination data, as these margarines were available on the Dutch market from 1999 onwards. Mean spontaneous daily use (g +/- SD) of phytosterol-containing margarine (n = 71) was 15 +/- 8 and of phytostanol-containing margarine (n = 13) 9+/-6. After five years, total blood cholesterol had increased with 0.26 mmol/l in non-users while it had not significantly changed in users. The difference in total blood cholesterol change in users versus non-users was -0.30 mmol/l (p < 0.001). The beneficial effect of the phytosterol/-stanol enriched margarine, used under customary conditions can be characterized as a stabilization of cholesterol levels. This is the first report finding a modest beneficial effect on blood cholesterol level under customary conditions thereby partly confirming findings from clinical trials
High energy solar neutrinos and p-wave contributions to ^3He(p,\nue^+)^4He
High energy solar neutrinos can come from the hep reaction ^3He(p,\nue^+)^4He
with a large end point energy of 18.8 MeV. Understanding the hep reaction may
be important for interpreting solar neutrino spectra. We calculate the
contribution of the axial charge transition to the hep
thermonuclear S factor using a one-body reaction model involving a nucleon
moving in optical potentials. Our result is comparable to or larger than
previous calculations of the s-wave Gamow Teller contribution. This indicates
that the hep reaction may have p-wave strength leading to an enhancement of the
S factor.Comment: 4 pages, 1 ps figure, very minor changes, Phys. Rev. C in pres
Inverting Time-Dependent Harmonic Oscillator Potential by a Unitary Transformation and a New Class of Exactly Solvable Oscillators
A time-dependent unitary (canonical) transformation is found which maps the
Hamiltonian for a harmonic oscillator with time-dependent real mass and real
frequency to that of a generalized harmonic oscillator with time-dependent real
mass and imaginary frequency. The latter may be reduced to an ordinary harmonic
oscillator by means of another unitary (canonical) transformation. A simple
analysis of the resulting system leads to the identification of a previously
unknown class of exactly solvable time-dependent oscillators. Furthermore, it
is shown how one can apply these results to establish a canonical equivalence
between some real and imaginary frequency oscillators. In particular it is
shown that a harmonic oscillator whose frequency is constant and whose mass
grows linearly in time is canonically equivalent with an oscillator whose
frequency changes from being real to imaginary and vice versa repeatedly.Comment: 7 pages, 1 figure include
Diagnostic value of real-time polymerase chain reaction to detect viruses in young children admitted to the paediatric intensive care unit with lower respiratory tract infection
INTRODUCTION: The aetiology of lower respiratory tract infections in young children admitted to the paediatric intensive care unit (PICU) is often difficult to establish. However, most infections are believed to be caused by respiratory viruses. A diagnostic study was performed to compare conventional viral tests with the recently developed real-time PCR technique. METHOD: Samples from children aged under 5 years presenting to a tertiary PICU suspected of having a lower respiratory tract infection were tested using conventional methods (viral culture and immunofluorescence) and real-time PCR during the winter season from December 2004 to May 2005. Conventional methods were used to check for respiratory syncytial virus, influenzavirus, parainfluenzavirus 1–3, rhinoviruses and adenoviruses. Real-time PCR was used to test for respiratory syncytial virus, influenzavirus, parainfluenzavirus 1–4, rhinoviruses, adenoviruses, human coronaviruses OC43, NL63 and 229E, human metapneumovirus, Mycoplasma pneumoniae and Chlamydia pneumoniae. RESULTS: A total of 23 patients were included, of whom 11 (48%) were positive for a respiratory virus by conventional methods. Real-time PCR confirmed all of these positive results. In addition, real-time PCR identified 22 more viruses in 11 patients, yielding a total of 22 (96%) patients with a positive sample. More than one virus was detected in eight (35%) children. CONCLUSION: Real-time PCR for respiratory viruses was found to be a sensitive and reliable method in PICU patients with lower respiratory tract infection, increasing the diagnostic yield twofold compared to conventional methods
Trans-eQTLs Reveal That Independent Genetic Variants Associated with a Complex Phenotype Converge on Intermediate Genes, with a Major Role for the HLA
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