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1.
Summary We have investigated the effects of high and low temperature on the synthesis and secretion of cellulases and other enzymes by two common and readily available strains ofTrichoderma reesei. While some effects were similar in both strains QM9414 and RUT-C30 (a reduction in cellulase production but stimulation of xylanase production at high temperature, and alterations in expression of the cellulase complex at low temperature), some specific differences between the strains were determined, most significantly an enhanced specific secretion rate (secretion/growth) at low growth temperature for QM9414.  相似文献   
2.
Weight discordance is very rare in monozygotic (MZ) twin pairs; when found, however, such pairs are advantageous in the search for either environmental or epigenetic causes and consequences of obesity. We analyzed the growth patterns of young adult MZ pairs discordant and concordant for obesity. Screening 5 consecutive birth cohorts (1975-1979) of 22- to 27-year-old Finnish twins (the FinnTwin16 study), we found 14 obesity discordant (Body Mass Index [BMI] difference > or = 4 kg/m2) MZ pairs out of 658. Ten pairs participated in clinical studies. Nine concordant pairs (BMI difference < or = 2 kg/m2) were examined as controls. Lifetime measured heights and weights recorded in hospitals and health centers were traced manually. Height development was similar in all the co-twins of both groups. The weight differences between the co-twins of the discordant pairs began to emerge at 18 years leading to an average discordance of 16.4 kg, 5.6 kg/m2 (p for both = .005) at 25.7 years. The heavier co-twin weighed 221 g (p = .066), 1.0 kg/m2 (p = .01) more already at birth than the leaner, but the differences waned by 6 months of age and reappeared only after adolescence. Both the leaner and the heavier co-twins of the discordant pairs weighed more than expected by the singleton reference values (Cole et al., 1998) after 8 years. The concordant co-twins, on the other hand, grew similarly and after 6 months, their mean growth was not distinguishable from the singleton patterns. Young adulthood represents a critical period of gaining weight irrespective of genetic background in this twin sample.  相似文献   
3.
The optimal conditions were established for extraction of paralytic shellfish toxins from a Danish clone of Alexandrium tamarense using extraction with acetic acid and HCl in the concentration range 0.01–1.0 N. Physical destruction of the cells was investigated microscopically to select the most efficient extraction procedure.The toxin content was quantitated by an automized isocratic reversed-phase high-performance liquid chromatography (HPLC) method. The best results as judged from the total amount of toxins and the toxin profile were obtained using 0.05–1.0 N acetic acid and 0.01–0.02 N HCl. Hydrochloric acid in the concentration range 0.03–1.0 N caused the amount of C1 and C2 toxins to decrease sharply and concomitant increase of gonyautoxins 2 and 3.The phytoplankton extracts with 0.1 to 0.5 N acetic acid or 0.01 N HCl were stable during 6 months at –20 °C, but the extracts with HCl 0.02 N underwent a change in toxin profile, although the total amount of toxins was constant.  相似文献   
4.
5.
Gaps in our current understanding and quantification of biomass carbon stocks, particularly in tropics, lead to large uncertainty in future projections of the terrestrial carbon balance. We use the recently published GlobBiomass data set of forest above‐ground biomass (AGB) density for the year 2010, obtained from multiple remote sensing and in situ observations at 100 m spatial resolution to evaluate AGB estimated by nine dynamic global vegetation models (DGVMs). The global total forest AGB of the nine DGVMs is 365 ± 66 Pg C, the spread corresponding to the standard deviation between models, compared to 275 Pg C with an uncertainty of ~13.5% from GlobBiomass. Model‐data discrepancy in total forest AGB can be attributed to their discrepancies in the AGB density and/or forest area. While DGVMs represent the global spatial gradients of AGB density reasonably well, they only have modest ability to reproduce the regional spatial gradients of AGB density at scales below 1000 km. The 95th percentile of AGB density (AGB95) in tropics can be considered as the potential maximum of AGB density which can be reached for a given annual precipitation. GlobBiomass data show local deficits of AGB density compared to the AGB95, particularly in transitional and/or wet regions in tropics. We hypothesize that local human disturbances cause more AGB density deficits from GlobBiomass than from DGVMs, which rarely represent human disturbances. We then analyse empirical relationships between AGB density deficits and forest cover changes, population density, burned areas and livestock density. Regression analysis indicated that more than 40% of the spatial variance of AGB density deficits in South America and Africa can be explained; in Southeast Asia, these factors explain only ~25%. This result suggests TRENDY v6 DGVMs tend to underestimate biomass loss from diverse and widespread anthropogenic disturbances, and as a result overestimate turnover time in AGB.  相似文献   
6.
Pre-eclampsia is a leading cause of maternal and perinatal morbidity and mortality worldwide. The etiology is not clear, but an immune attack towards components of placenta or fetus has been indicated. This involves activation of the complement system in the placenta. We have previously described the presence of the complement-regulating protein salivary scavenger and agglutinin (SALSA) in amniotic fluid. In this study we investigated the potential role of SALSA in pregnancy by analyzing its presence in amniotic fluid and placental tissue during healthy and complicated pregnancies. SALSA levels in amniotic fluid increased during pregnancy. Before 20 weeks of gestation the levels were slightly higher in patients who later developed pre-eclampsia than in gestation age-matched controls. In the placenta of pre-eclamptic patients syncytial damage is often followed by the formation of fibrinoid structures. SALSA was found clustered into these fibrinoid structures in partial co-localization with complement C1q and fibronectin. In vitro analysis showed direct protein binding of SALSA to fibronectin. SALSA binds also to fibrin/fibrinogen but did not interfere with the blood clotting process in vitro. Thus, in addition to antimicrobial defense and epithelial differentiation, the data presented here suggest that SALSA, together with fibronectin and C1q, may be involved in the containment of injured placental structures into fibrinoids.  相似文献   
7.
Both genetic and environmental factors are involved in the etiology of obesity and the associated lipid disturbances. We determined whether acquired obesity is associated with changes in global serum lipid profiles independent of genetic factors in young adult monozygotic (MZ) twins. 14 healthy MZ pairs discordant for obesity (10 to 25 kg weight difference) and ten weight concordant control pairs aged 24-27 years were identified from a large population-based study. Insulin sensitivity was assessed by the euglycemic clamp technique, and body composition by DEXA (% body fat) and by MRI (subcutaneous and intra-abdominal fat). Global characterization of lipid molecular species in serum was performed by a lipidomics strategy using liquid chromatography coupled to mass spectrometry. Obesity, independent of genetic influences, was primarily related to increases in lysophosphatidylcholines, lipids found in proinflammatory and proatherogenic conditions and to decreases in ether phospholipids, which are known to have antioxidant properties. These lipid changes were associated with insulin resistance, a pathogonomic characteristic of acquired obesity in these young adult twins. Our results show that obesity, already in its early stages and independent of genetic influences, is associated with deleterious alterations in the lipid metabolism known to facilitate atherogenesis, inflammation and insulin resistance.  相似文献   
8.
Transrectal or transabdominal examinations of 13 pluriparous reindeer (Rangifer tarandus tarandus) by ultrasonography from the start of mating until week 20 of gestation were conducted to find out when pregnancy could first be detected and to describe fetal development in early pregnancy. The examinations (n=35 per animal) were performed with a 5 MHz linear transducer from 7th October until 1st January and with a 3 MHz sector transducer from that time until 24th February. Time of pregnancy diagnosis by ultrasonography, the first fetal heartbeat and measurements of crown-rump length, chest width and chest depth were recorded during the examinations. Pregnancy was diagnosed by transrectal ultrasonography between the weeks 3 and 7 of gestation. The accuracy of the pregnancy diagnosis, defined as the proportion of females correctly detected to be pregnant, was 15% at week 3, 46% at week 4, 77% at week 5, and 92% at week 6 of gestation. Fetal heartbeat was first detected between the weeks 5 and 8 of gestation. The first measurements of crown-rump length were made on week 3 of gestation, of chest width on week 4 and of chest depth on week 5 of gestation. Chest width and depth were detectable until the end of the study at week 20 of gestation. Transrectal ultrasonography is an efficient tool in early pregnancy diagnosis of reindeer. The fetal growth curves obtained by ultrasonography resembled those obtained in previous morphological studies.  相似文献   
9.
Preeclampsia is a common, pregnancy-specific disorder characterized by reduced placental perfusion, endothelial dysfunction, elevated blood pressure, and proteinuria. The pathogenesis of this heterogeneous disorder is incompletely understood, but it has a familial component, which suggests that one or more common alleles may act as susceptibility genes. We hypothesized that, in a founder population, the genetic background of preeclampsia might also show reduced heterogeneity, and we have performed a genomewide scan in 15 multiplex families recruited predominantly in the Kainuu province in central eastern Finland. We found two loci that exceeded the threshold for significant linkage: chromosome 2p25, near marker D2S168 (nonparametric linkage [NPL] score 3.77; P=.000761) at 21.70 cM, and 9p13, near marker D9S169 (NPL score 3.74; P=.000821) at 38.90 cM. In addition, there was a locus showing suggestive linkage at chromosome 4q32 between D4S413 and D4S3046 (NPL score 3.13; P=.003238) at 163.00 cM. In the present study the susceptibility locus on chromosome 2p25 is clearly different (21.70 cM) from the locus at 2p12 found in an Icelandic study (94.05 cM) and the locus at 2q23 (144.7 cM) found in an Australian/New Zealand study. The locus at 9p13 has been shown to be a candidate region for type 2 diabetes in two recently published genomewide scans from Finland and China. The regions on chromosomes 2p25 and 9p13 may harbor susceptibility genes for preeclampsia.  相似文献   
10.
Tartrate-resistant acid phosphatase (TRACP) is an enzyme with unknown biological function. In addition to its acid phosphatase activity, TRACP is capable of generating reactive oxygen species (ROS) at neutral pH. Two forms of TRACP circulate in human serum, macrophage-derived TRACP 5a and osteoclast-derived TRACP 5b. Here we have studied the circulating forms of the osteoclast-derived TRACP 5b in rat and human serum. In human serum, TRACP 5b circulates in a large complex that contained α2M and calcium. On the contrary, rat serum TRACP 5b circulates as a free molecule. Formation of the TRACP 5b complex in vitro decreased significantly the ROS generating activity of TRACP 5b without affecting its phosphatase activity. These results suggest that the complex formation may be necessary to eliminate the formation of the harmful ROS in the neutral pH of serum.  相似文献   
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