Isolation and identification of oligomeric procyanidins from Crataegus leaves and flowers

Oligomeric procyanidins were isolated from the leaves and flowers of hawthorn (Crataegus laevigata). A trimer, epicatechin-(4β→8)-epicatechin-(4β→6)-epicatechin, and a pentamer consisting of (−)-epicatechin units linked through C-4β/C-8 bonds have been isolated from hawthorn for the first time, in addition to known procyanidins including dimers B-2, B-4 and B-5, trimers C-1 and epicatechin-(4β→6)-epicatechin-(4β→8)-epicatechin, and tetramer D-1. A fraction containing a hexamer was also found.     

Alpha-lactorphin and beta-lactorphin improve arterial function in spontaneously hypertensive rats

alpha-lactorphin (Tyr-Gly-Leu-Phe) lowers blood pressure in conscious adult SHR. This tetrapeptide is originally released from milk protein alpha-lactalbumin by enzymatic hydrolysis. In order to evaluate the antihypertensive mechanisms of alpha-lactorphin, the effects of the tetrapeptide on vascular function were investigated in (30-35 weeks old) spontaneously hypertensive rats (SHR) with established hypertension and age-matched normotensive Wistar-Kyoto (WKY) rats in vitro. In addition, we studied the vascular effects of another structurally related tetrapeptide, beta-lactorphin (Tyr-Leu-Leu-Phe), which originates from milk protein beta-lactoglobulin. Endothelium-dependent relaxation to acetylcholine (ACh) was reduced in mesenteric arterial preparations of SHR as compared to those of WKY. In SHR, the ACh-induced relaxation was augmented by alpha-lactorphin or beta-lactorphin. The role of nitric oxide (NO) is suggested, since this improvement was abolished by the NO synthase (NOS) inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME). Simultaneous potassium channel inhibitor tetraethylammonium (TEA) elicited no additional effect on the ACh-induced relaxation. The cyclooxygenase inhibitor diclofenac did not attenuate the augmented ACh relaxation induced by alpha-lactorphin or beta-lactorphin, suggesting that endothelial vasodilatory prostanoids were not involved in the effect of the tetrapeptides. Endothelium-independent relaxation to the NO donor sodium nitroprusside (SNP) was augmented in mesenteric arterial preparations of SHR by simultaneous beta-lactorphin. The tetrapeptides did not alter vascular responses in mesenteric arteries from WKY. In conclusion, both alpha-lactorphin and beta-lactorphin improved vascular relaxation in adult SHR in vitro. The beneficial effect of alpha-lactorphin was directed towards endothelial function, whereas beta-lactorphin also enhanced endothelium-independent relaxation.     

Forest management is associated with physiological stress in an old-growth forest passerine

We investigated how physiological stress in an area-sensitive old-growth forest passerine, the Eurasian treecreeper (Certhia familiaris), is associated with forest fragmentation and forest structure. We found evidence that the concentrations of plasma corticosterone in chicks were higher under poor food supply in dense, young forests than in sparse, old forests. In addition, nestlings in large forest patches had lower corticosterone levels and a better body condition than in small forest patches. In general, corticosterone levels were negatively related to body condition and survival. We also found a decrease in corticosterone levels within the breeding season, which may have been a result of an increase in food supply from the first to the second broods. Our results suggest that forest fragmentation may decrease the fitness of free-living individual treecreepers.     

Gene expression profiles in chondrosarcoma cells subjected to cyclic stretching and hydrostatic pressure. A cDNA array study

Mechanical forces have a profound effect on cartilage tissue and chondrocyte metabolism. Strenuous loading inhibits the cellular metabolism, while optimal level of loading at correct frequency raises an anabolic response in chondrocytes. In this study, we used Atlas Human Cancer cDNA array to investigate mRNA expression profiles in human chondrosarcoma cells stretched 8% for 6 hours at a frequency of 0.5 Hz. In addition, cultures were exposed to continuous and cyclic (0.5 Hz) 5 MPa hydrostatic pressure. Cyclic stretch had a more profound effect on the gene expression profiles than 5 MPa hydrostatic pressure. Several genes involved with the regulation of cell cycle were increased in stretched cells, as well as mRNAs for PDGF-B, glucose-1-phosphate uridylyltransferase, Tiam1, cdc37 homolog, Gem, integrin alpha6, and matrix metalloproteinase-3. Among down-regulated genes were plakoglobin, TGF-alpha, retinoic acid receptor-alpha and Wnt8b. A smaller number of changes was detected after pressure treatments. Plakoglobin was increased under cyclic and continuous 5 MPa hydrostatic pressure, while mitogen-activated protein kinase-9, proliferating cell nuclear antigen, Rad6, CD9 antigen, integrins alphaE and beta8, and vimentin were decreased. Cyclic and continuous pressurization induces a number of specific changes. In conclusion, a different set of genes were affected by three different types of mechanical stimuli applied on chondrosarcoma cells.     

Effect of a 902 MHz electromagnetic field emitted by mobile phones on human cognitive function: A replication study

Our study was a replication and extension with methodological improvements to a previous study on effects of the electromagnetic field (EMF) emitted by a 902 MHz mobile phone on human cognitive functioning. Improvements on the previous study included multicentre testing and a double blind design. A total of 64 subjects (32 men and 32 women) in two independent laboratories performed a battery of 9 cognitive tasks twice: while the EMF was on and while it was off. Reaction times (RTs) and accuracy were recorded. The order of exposure and tasks was counterbalanced across subjects and gender. There were no statistically significant differences in performance between genders or laboratories. Although the RTs and the accuracy of answers were very similar to those of our previous study, our previous results were not replicated. We concluded that EMF had no effect on RTs or on the accuracy of the subjects' answers. Further, our results indicate that our EMF had no immediate effect on human cognitive functioning or that such effects are so small that they are observed on behavior only occasionally.     

Cardiovascular autonomic function correlates with the response to aerobic training in healthy sedentary subjects

Individual responses to aerobic training vary from almost none to a 40% increase in aerobic fitness in sedentary subjects. The reasons for these differences in the training response are not well known. We hypothesized that baseline cardiovascular autonomic function may influence the training response. The study population included sedentary male subjects (n = 39, 35 +/- 9 yr). The training period was 8 wk, including 6 sessions/wk at an intensity of 70-80% of the maximum heart rate for 30-60 min/session. Cardiovascular autonomic function was assessed by measuring the power spectral indexes of heart rate variability from 24-h R-R interval recordings before the training period. Mean peak O2 uptake increased by 11 +/- 5% during the training period (range 2-19%). The training response correlated with age (r = -0.39, P = 0.007) and with the values of the high-frequency (HF) spectral component of R-R intervals (HF power) analyzed over the 24-h recording (r = 0.46, P = 0.002) or separately during the daytime hours (r = 0.35, P = 0.028) and most strongly during the nighttime hours (r = 0.52, P = 0.001). After adjustment for age, HF power was still associated with the training response (e.g., P = 0.001 analyzed during nighttime hours). These data show that cardiovascular autonomic function is an important determinant of the response to aerobic training among sedentary men. High vagal activity at baseline is associated with the improvement in aerobic power caused by aerobic exercise training in healthy sedentary subjects.     

Polymorphisms in the tyrosine kinase 2 and interferon regulatory factor 5 genes are associated with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a complex systemic autoimmune disease caused by both genetic and environmental factors. Genome scans in families with SLE point to multiple potential chromosomal regions that harbor SLE susceptibility genes, and association studies in different populations have suggested several susceptibility alleles for SLE. Increased production of type I interferon (IFN) and expression of IFN-inducible genes is commonly observed in SLE and may be pivotal in the molecular pathogenesis of the disease. We analyzed 44 single-nucleotide polymorphisms (SNPs) in 13 genes from the type I IFN pathway in 679 Swedish, Finnish, and Icelandic patients with SLE, in 798 unaffected family members, and in 438 unrelated control individuals for joint linkage and association with SLE. In two of the genes—the tyrosine kinase 2 (TYK2) and IFN regulatory factor 5 (IRF5) genes—we identified SNPs that displayed strong signals in joint analysis of linkage and association (unadjusted P<10^-7) with SLE. TYK2 binds to the type I IFN receptor complex and IRF5 is a regulator of type I IFN gene expression. Thus, our results support a disease mechanism in SLE that involves key components of the type I IFN system.     

Meta-analysis in assessment of the prevalence and annual incidence of Giardia spp. and Cryptosporidium spp. infections in humans in the Nordic countries

We aimed to apply the meta-analysis in the studies of protozoan pathogens in order to obtain a general overview of the prevalence and annual incidence of Giardia spp. and Cryptosporidium spp. infections in asymptomatic and symptomatic human populations in the Nordic countries of Denmark, Finland, Norway and Sweden. In combining the data of 13 clinically and methodologically non-heterogeneous studies published before 2004 using the random effects model with DerSimonian-Laird estimator, we estimated the prevalence (% prevalence: 95% confidence limits) of Giardia cases in the asymptomatic (i.e. no gastroenteric symptoms) general population to be 2.97% (2.64; 3.31) and in the symptomatic population 5.81% (5.34; 6.30). For Cryptosporidium the prevalences were 0.99% (0.81; 1.19) and 2.91% (2.71; 3.12), respectively. In analyzing the data, we estimated that there will be 4670 (4300; 5060) symptomatic cases of Giardia and 3340 (3110; 3580) symptomatic cases of Cryptosporidium annually per 100,000 general population in the Nordic countries. The vast majority of cases will remain unregistered in the national registers of infectious diseases, since for single registered cases there will be 254-867 cases of Giardia undetected/unregistered and 4072 to 15,181 cases of Cryptosporidium, respectively.