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At least 829 records · Page 46Linked to original sources
PubMed2005

Quantitative assessment of regional myocardial function with MR-tagging in a multi-center study: interobserver and intraobserver agreement of fast strain analysis with Harmonic Phase (HARP) MRI.

PURPOSE: To assess the reproducibility of Harmonic Phase (HARP) analysis of myocardial MR tagged images acquired in the Multi-Center Study of Atherosclerosis (MESA). METHODS: Using the HARP method, three independent observers performed two separate quantitative strain analyses of myocardial cine MR-tagging images blindly in 24 participants. The images were obtained in four different centers and analyzed at a single core lab. Each study comprised 3 short-axis slices subdivided in 12 segments (24 x 3 x 12 = 864 segments), each with three layers. Normal strains (circumferential [Ecc] and radial [Err]), principal strains (Lambda1, Lambda2), and the angle alpha (between Ecc-Lambda2) were calculated. Intraclass correlation coefficient (R) for peak systolic strains, and all pooled systolic and diastolic strain data were used to determine inter- and intraobserver agreement. Two observers also visually graded study quality. R values were related to the image quality in different myocardial regions and layers. RESULTS: Overall, HARP yielded an excellent inter- and intraobserver agreement for peak systolic strain data (for Ecc, R = 0.84 and 0.89, respectively) and all systolic pooled data (for Ecc, interobserver R = 0.82, intraobserver R = 0.69-0.76). Both inter and intraobserver agreement were lower for diastolic pooled data (R = 0.69 and 0.58-0.62, respectively). There was a direct relationship between image quality and performance of the HARP analysis, with increasing inter- and intraobserver R values in studies with longer tag persistence. Both inter- and intraobserver agreement were better in the anterior and septal myocardial regions, and in the midwall layer. The intraobserver agreement was similar among the three observers. CONCLUSION: Employing the HARP method for quantitative strain analysis of myocardial MR tagged images provides a high inter- and intraobserver agreement. These good results are obtained in case of good to excellent MR image quality.

Aged↗
PubMed2003

Impaired glucose homeostasis, neutrophil trafficking and function in mice lacking the glucose-6-phosphate transporter.

Glycogen storage disease type Ib (GSD-Ib) is caused by a deficiency in the glucose-6-phosphate transporter (G6PT). In addition to disrupted glucose homeostasis, GSD-Ib patients have unexplained and unexpected defects in neutrophil respiratory burst, chemotaxis and calcium flux, in response to the bacterial peptide f-Met-Leu-Phe, as well as intermittent neutropenia. We generated a G6PT knockout (G6PT-/-) mouse that mimics all known defects of the human disorder and used the model to further our understanding of the pathogenesis of GSD-Ib. We demonstrate that the neutropenia is caused directly by the loss of G6PT activity; that chemotaxis and calcium flux, induced by the chemokines KC and macrophage inflammatory protein-2, are defective in G6PT-/- neutrophils; and that local production of these chemokines and the resultant neutrophil trafficking in vivo are depressed in G6PT-/- ascites during an inflammatory response. The bone and spleen of G6PT-/- mice are developmentally delayed and accompanied by marked hypocellularity of the bone marrow, elevation of myeloid progenitor cell frequencies in both organs and a corresponding dramatic increase in granulocyte colony stimulating factor levels in both GSD-Ib mice and humans. So, in addition to transient neutropenia, a sustained defect in neutrophil trafficking due to both the resistance of neutrophils to chemotactic factors, and reduced local production of neutrophil-specific chemokines at sites of inflammation, may underlie the myeloid deficiency in GSD-Ib. These findings demonstrate that G6PT is not just a G6P transport protein but also an important immunomodulatory protein whose activities need to be addressed in treating the myeloid complications in GSD-Ib patients.

Animals↗
PubMed2002

Molecular evolution of adrenarche: structural and functional analysis of p450c17 from four primate species.

Adrenarche is the prepubertal onset of increased adrenal secretion of 19-carbon steroids, especially dehydroepiandrosterone (DHEA). However, while human beings and chimpanzees exhibit adrenarche, other primates such as the baboon and rhesus monkey do not, and the adrenals of most other mammals produce little or no DHEA. Thus, the acquisition of adrenarche is a very recent evolutionary event. DHEA is produced from pregnenolone by the successive 17alpha-hydroxylase and 17,20 lyase activities of a single enzyme, P450c17. To ascertain whether sequence differences in P450c17 contribute to adrenarche, we cloned the rhesus monkey cDNA from adrenal tissue and cloned the chimpanzee and baboon cDNAs from genomic DNA using an exon-trapping strategy. Using microsomes from yeast transformed with rhesus, baboon, chimp, or human P450c17, we measured the Michaelis constant and maximum velocity for the 17alpha-hydroxylase and 17,20 lyase activities. The human and chimp enzymes differ at only two amino acids and baboon and rhesus P450c17 only at a single residue; the human/chimp enzyme differed from the baboon/rhesus enzyme by 25-27 residues (95% identity). Surprisingly, the greatest difference in enzymatic activities was a marked increase in 17alpha-hydroxylase activity of P450c17 in the baboon, which differs from rhesus only at residue 255 [arginine (Arg) in baboon, histine (His) in rhesus]. Residue 255 is also Arg in human and chimp. Wild-type human P450c17 and its Arg255His mutant had similar 17alpha-hydroxylase activities, but the Arg255Ala mutant had decreased 17alpha-hydroxylase activity. These data establish that Arg255 is important for 17alpha-hydroxylase activity and show that the evolution of adrenarche in higher primates is not determined by variations in the sequence of P450c17.

Adrenal Glands↗
PubMed1983

Human T lymphocyte proliferation induced by a pan-T monoclonal antibody (anti-Leu 4): heterogeneity of response is a function of monocytes.

Anti-Leu-4 is a murine monoclonal antibody that defines a molecule of 20,000 to 25,000 daltons present on all mature T lymphocytes in man. When cultured in the presence of 10 to 1000 ng/ml anti-Leu-4, the T cells of most individuals proliferate with peak responses on the third day of culture. T cells of both helper and suppressor lineages proliferate, but only in the presence of monocytes. Approximately 40% of individuals tested responded weakly or not at all to anti-Leu-4, despite normal responses to other stimuli. The variation in responsiveness between individuals could not be explained by differences in Leu-4 antigen density on the surface of T cells, differences in the rate of Leu-4 antigen modulation, or structural differences in the Leu-4 molecule as defined by the method of two-dimensional polyacrylamide gel electrophoresis. In the presence of monocytes from high responders, the T cells from low responders proliferated vigorously to anti-Leu-4, whereas monocytes from low responders failed to support proliferation by high responder T cells. On the other hand, low responder monocytes did not prevent T cells from proliferating in the presence of high responder monocytes. These results suggest that the failure of some individuals to respond to anti-Leu-4 is due to the absence or dysfunction of an essential monocyte population.

Adult↗
PubMed2006

Genetic and antigenic typing of border disease virus isolates in sheep from the Iberian Peninsula.

A selection of 10 pestiviruses isolated from sheep from the Iberian Peninsula from 2001 to 2004 was characterised at the molecular level. The 5' untranslated region (5'-UTR) and N(pro)-coding gene were amplified by the reverse transcription-polymerase chain reaction (RT-PCR) and sequenced directly from purified products. All isolates were also typed antigenically with a panel of monoclonal antibodies (mAbs) raised against representative isolates of the four recognised pestivirus species. The genetic typing placed all the isolates in a new tentative type 4 of border disease virus (BDV), which was closely related to a pestivirus recently found in Pyrenean chamois (Rupicapra pyrenaica pyrenaica). Overall, the genotyping indicated a relatively wide diversity of the BDV type 4, which was best defined on the basis of N(pro) sequences. Antigenically, the isolates were recognised by two pan-pestivirus specific anti-NS3 mAbs, but only by some of the anti-glycoprotein specific mAbs raised against BDV, indicating partial antigenic overlap with other BDV isolates.

5' Untranslated Regions↗
PubMedDate not supplied

The relationship between speed, contact time and peak plantar pressure in terrestrial walking of bonobos.

The aim of this paper is twofold. Firstly, we investigate whether contact times, as recorded by pedobarographic systems during quadrupedal and bipedal walking of bonobos, can be used to reliably calculate actual velocities, by applying formulae based on lateral-view video recordings. Secondly, we investigate the effect of speed on peak plantar pressures during bipedal and quadrupedal walking of the bonobo. Data were obtained from 4 individuals from a group of bonobos at the Animal Park Planckendael. From our study, we can conclude that both walking speeds calculated from contact times and lower leg length or simply from recorded contact times are good estimators for walking speed, when direct observation of the latter is impossible. Further, it was found that effects of speed on peak plantar pressures and vertical forces are absent or at least subtle in comparison to a large variation in pressure patterns. In bonobos, the same pressure patterns are used at all walking speeds, and, in consequence, we do not expect major changes in foot function.

Analysis of Variance↗
PubMed1997

Relationship between Asbestos Exposures and 8-Hydroxydeoxyguanosine Levels in Leukocytic DNA of Workers at a Chinese Asbestos-material Plant.

The objective of the study was to evaluate the level of 8-hydroxydeoxyguanosine (8-OHdG) in DNA of peripheral-blood leukocytes as a biological marker of asbestos exposure and/or its fibrotic effects in an occupational population exposed to asbestos. The setting was a large-scale asbestos plant in China producing brake linings, asbestos rubber, and textile using chrysotile. From a base population of active and retired workers with various levels of cumulative exposure to asbestos and grades of asbestosis, 39 study subjects were randomly selected to reflect incremental grades of asbestosis based on Chinese diagnostic standards. They consisted of 19 "normal" (control) and ten "suspected" and ten "definite" asbestosis-grade subjects, group-matched for age and sex. Leukocytic DNA was extracted from 5-mL samples of peripheral blood and 8-OHdG level measured by high-pressure liquid chromatography. A cumulative asbestos exposure index (CEI) was calculated for each subject as the summed product of duration and level of asbestos exposure per job, incorporating a job-exposure matrix. Geometric mean 8-OHdG levels showed a positive gradient in relation to increasing grades of asbestosis (control: 1.78, suspected: 2.21, definite: 2.58), with a significant difference between the control and definite-asbestosis subgroups (p < 0.05). The 8-OHdG level of the two subgroups combined as one "asbestosis" group was significantly higher than that of the control group (control: 1.78, asbestosis: 2.39, p = 0.01). Further, 8-OHdG levels were moderately correlated with CEIs for all subjects (r = 0.35, p < 0.05) and with grades of asbestosis for all (r = 0.47, p < 0.01) and for male subjects (r = 0.43, p < 0.05). In multiple regression analyses, grade of asbestosis explained 27% of the total variation in 8-OHdG and was a better predictor than CEI or duration of exposure. Thus, the 8-OHdG level in leukocytic DNA is related to grade of asbestosis and to individual cumulative exposure and may serve as a biologic marker reflecting the status of oxidative DNA damage by asbestos.

Journal Article↗
PubMed2006

[Study on intraspecific genetic diversity in different plant populations of Pogostemon cabli].

OBJECTIVE: To study the genetic polymorphism and intraspecific genetic differentiation of different populations of Pogostemon cablin, and find out the effective method to distinguish DNA fingerprint of different populations of P. cablin. METHOD: Five plant populations of P. cablin were analyzed by RAPD markers. PopGen 32 software for clustering analysis and calculating. Fourteen of the 80 random primers were tested to possess the stronger detecting effect of polymorphous character. RESULT: A total of 84 bands was amplified by the 10 primers, among them 17 bands were monomorphic. 67 of them were polymorphic. The results indicated that the genetic variations existed within the different plant populations of the same species. CONCLUSION: It is feasible by RAPD technique with specifically primer to analyze the genetic diversity and identify 5 plant populations of P. cablin. RAPD technique has provided a new path for identification and classification of P. cablin genetic germplasm.

China↗
PubMed2004

Fermentation of a milk-soymilk and Lycium chinense Miller mixture using a new isolate of Lactobacillus paracasei subsp. paracasei NTU101 and Bifidobacterium longum.

A milk-soymilk mixture was fermented using Lactobacillus paracasei subsp. paracasei NTU101 and Bifidobacterium longum BCRC11847 at different inoculum ratios (1:1, 1:2, 1:5, 2:1, and 5:1). When the inoculum ratio was 1:2, the cell numbers of both strains were balanced after 12 h of cultivation. The pH and titratable acidity were very similar at the various inoculum ratios of cultivation. The milk-soymilk mixture was supplemented with 5, 10, 15, and 20% Lycium chinense Miller juice and fermented with Lactobacillus paracasei subsp. paracasei NTU101 and B. longum BCRC11847. Sensory evaluation results showed that supplementation with 5% Lycium chinense Miller juice improved the acceptability of the fermented milk-soymilk. The fermented beverage was stored at 4 degrees C for 14 days; variations in pH and titratable acidity were slight. The cell numbers of L. paracasei subsp. paracasei NTU101 and B. longum BCRC11847 in the fermented beverage were maintained at 1.2x10(9) CFU/ml and 6.3x10(8) CFU/ml, respectively, after 14 days of storage.

Animals↗
PubMed2000

Primary renal vasculitis in Norfolk--increasing incidence or increasing recognition?

BACKGROUND: The incidence of renal vasculitis has previously been estimated using histological definitions or only a single clinical diagnosis, e.g. Wegener's Granulomatosis (WG). Our hospital is the single referral centre for the former Norwich Health Authority (NHA) which encompasses a stable, homogeneous, well-defined and studied population. We estimated the overall incidence of primary renal vasculitis and the incidence within individual clinical disease classifications. METHODS: All cases of primary renal vasculitis diagnosed within the NHA over 66 months (1992-1997) were identified by review of renal biopsies, the Norfolk Vasculitis Register, hospital discharge summaries and plasmapheresis records. Patients were classified using the 1990 American College of Rheumatology criteria for Polyarteritis Nodosa (PAN), Churg Strauss Syndrome (CSS) and Henoch-Schonlein Purpura; the Chapel Hill Consensus Conference Definitions for Microscopic Polyangiitis (mPA) and the Lanham criteria for CSS. Incidence figures were calculated using the NHA adult population of 413747 (1994). Ninety-five per cent confidence intervals (C.I.) were calculated using the poisson distribution. RESULTS: The overall annual incidence for primary renal vasculitis was 18/million (C.I. 12.9-24.4). The annual incidence of renal involvement of individual diseases was as follows: WG 7.9/million (95% C.I. 4.7-12.5); mPA 7.5/million (95% C. I. 4.4-12.0); PAN 7.0/million (95% C.I. 4.0-11.4); HSP 3.1/million (95% C.I. 1.2-6.3); CSS 1.3/million (95% C.I. 0.3-3.9). CONCLUSIONS: The annual incidence for primary renal vasculitis overall and the individual subtypes in Norfolk is much higher than previous European estimates. This may reflect an increasing incidence in primary renal vasculitis with time or underestimation in previous studies. However the incidence of renal vasculitis in our population is markedly lower than reported in Kuwait. There may therefore be true variation in incidence between populations which could have implications for the aetiology of primary vasculitis.

Adult↗
PubMed2004

Effect of carbon source and nitrate concentration on denitrifying phosphorus removal by DPB sludge.

Effect of added carbon source and nitrate concentration on the denitrifying phosphorus removal by DPB sludge was systematically studied using batch experiments, at the same time the variation of ORP was investigated. Results showed that the denitrifying and phosphorus uptake rate in anoxic phase increased with the high initial anaerobic carbon source addition. However once the initial COD concentration reached a certain level, which was in excess to the PHB saturation of poly-P bacteria, residual COD carried over to anoxic phase inhibited the subsequent denitrifying phosphorus uptake. Simultaneously, phosphate uptake continued until all nitrate was removed, following a slow endogenous release of phosphate. High nitrate concentration in anoxic phase increased the initial denitrifying phosphorus rate. Once the nitrate was exhausted, phosphate uptake changed to release. Moreover, the time of this turning point occurred later with the higher nitrate addition. On the other hand, through on-line monitoring the variation of the ORP with different initial COD concentration, it was found ORP could be used as a control parameter for phosphorus release, but it is impossible to utilize ORP for controlling the denitrificaion and anoxic phosphorus uptake operations.

Bacteria, Anaerobic↗
PubMed2003

Human estrogen receptor beta 548 is not a common variant in three distinct populations.

Several isoforms of estrogen receptor (ER) beta (also known as NR3A2) have been reported, including variants with different N-terminal ends. In rodents, two in-frame initiation codons (ATGs) are used to produce proteins of 530 and 549 amino acids, respectively. In humans, the upstream ATG is out of frame in all clones reported, until recently, when human clones with an extra A-T base pair placing the upstream ATG in frame were reported. The authors suggested that this could represent a novel polymorphism in the ERbeta gene. Because human ERbeta548 (hERbeta548) and hERbeta530 display different functional characteristics in vitro, it is of interest to determine if this variant constitutes a polymorphism in human populations. We therefore determined the frequency of this novel isoform in several populations including African (n = 96), Caucasian (n = 100), and Asian (n = 128) subjects using denaturing HPLC. We did not detect any alleles that correspond to hERbeta548 in these samples or in additional samples of heterogeneous origin. It is concluded that hERbeta548 is not a common variant in Africans, Caucasians, or Asians.

Alleles↗
PubMed1997

Sensitive and specific high-performance liquid chromatographic assay with ultraviolet detection for the determination of cocaine and its metabolites in rat plasma.

A sensitive, specific and precise HPLC-UV assay was developed to quantitate cocaine (COC) and its metabolites benzoylecgonine (BE), norcocaine (NC) and cocaethylene (CE) in rat plasma. After adding 50 microl of the internal standard solution (bupivacaine, 8 microg/ml) and 500 microl of Sørensen's buffer (pH 6) to 100 microl of rat plasma sample, the mixture was extracted with 10 ml of chloroform. The organic layer was transferred to a clean test tube and was evaporated under nitrogen. The residue was reconstituted in 100 microl of mobile phase and 35 microl was injected onto the HPLC column. The mobile phase consisted of methanol-acetonitrile-50 mM monobasic ammonium phosphate (5:7:63, v/v/v) and was maintained at a flow-rate of 0.4 ml/min. Separation of COC and its metabolites was achieved using a Supelcosil ABZ+plus deactivated reversed-phase column (250x2.1 mm I.D., 5 microm). Calibration curves were linear over the range of 25-5000 ng/ml for COC and its three metabolites. The absolute extraction efficiencies for BE, COC, NC, CE and bupivacaine were 56.6%, 78.6%, 61.1%, 76.4% and 67.0%, respectively. COC and its metabolites were stable in mobile phase for 24 h at room temperature and in rat plasma for 2 weeks at -20degrees C. The limits of detection for BE, COC, NC and CE were 20, 24, 15 and 12.9 ng/ml, respectively. These values correspond to 0.70, 0.84, 0.525 and 0.452 ng of the according compound being injected on column. The within-day coefficient of variation for the four compounds ranged from 3.0% to 9.9% while the between-day precision varied from 3.6% to 14%. This method was used to analyze rat plasma samples after administration of COC alone and in combination with alcohol. The pharmacokinetic profiles of COC and its metabolites in these rats are also described.

Animals↗
PubMed1986

[Drug treatment of oligospermia of idiopathic origin. Critical review].

Controlled studies are essential in any evaluation of the effects of treatment in cases of sterility due to oligospermia because of the important inter-individual variations in the sperm count and in the spontaneous pregnancy rate. The various hormonal and non-hormonal treatments for idiopathic oligospermia are described with special emphasis on the results of double-blind studies. Future prospects for the treatment of male sterility by in vitro fertilisation are then discussed.

Androgens↗
PubMed1995

How much blame can be placed on laser photocoagulation for failure to attain driving standards?

One hundred consecutive patients who underwent bilateral pan-retinal photocoagulation (PRP) for proliferative diabetic retinopathy were assessed in accordance with the UK Driver and Vehicle Licensing Agency (DVLA) guidelines. Visual acuity was documented, and visual fields were assessed using the Esterman test. Among the 30% of patients who failed to reach the visual standards required for a driving licence, three groups were identified: those who failed to attain either the required binocular visual acuity (n = 4), or visual fields (n = 9), or both (n = 17). Previous studies reveal a large variation in DVLA field test failure following PRP treatment for proliferative diabetic retinopathy. Our results show a 19% failure rate solely attributable to treatment, which is at the lower end of previously reported studies (20-80%). The reasons for this discrepancy are discussed. We conclude that modern treatment procedures for proliferative diabetic retinopathy may be undertaken with the knowledge that in the majority of cases a patient's driving licence is unlikely to be revoked.

Automobile Driver Examination↗
PubMed2006

Structural divergence between the human and chimpanzee genomes.

The structural microheterogeneity evident between the human and chimpanzee genomes is quite considerable and includes inversions and duplications as well as deletions, ranging in size from a few base-pairs up to several megabases (Mb). Insertions and deletions have together given rise to at least 150 Mb of genomic DNA sequence that is either present or absent in humans as compared to chimpanzees. Such regions often contain paralogous sequences and members of multigene families thereby ensuring that the human and chimpanzee genomes differ by a significant fraction of their gene content. There is as yet no evidence to suggest that the large chromosomal rearrangements which serve to distinguish the human and chimpanzee karyotypes have influenced either speciation or the evolution of lineage-specific traits. However, the myriad submicroscopic rearrangements in both genomes, particularly those involving copy number variation, are unlikely to represent exclusively neutral changes and hence promise to facilitate the identification of genes that have been important for human-specific evolution.

Animals↗
PubMed2006

Dental metric comparisons of Morotopithecus and Afropithecus: implications for the validity of the genus Morotopithecus.

Morotopithecus bishopi and Afropithecus turkanensis are two large-bodied hominoid primates from early Miocene deposits of eastern Africa. Researchers have used both cranial and postcranial characters to distinguish these two species. Unfortunately, of the fossil material attributed to each, only the face, palate, and upper dentition are preserved well enough in both species for direct comparisons. There are currently no known directly comparable postcranial elements. In this study, we reevaluated dental characters argued to distinguish the type specimens of Morotopithecus from Afropithecus: relative size of the upper premolars and M3. Exact randomization methods were used to address two questions. First, is it possible to find the degree of dental-size difference observed between Morotopithecus (UMP 62-11) and Afropithecus (KNM-WK 16999) within extant African hominoids? Second, what is the probability of observing the levels of difference found between the fossils among pairs of extant individuals? Metric differences in relative premolar and M3 size were calculated between all possible pairs within the extant sample and the observed difference of the fossil pair was then compared to the resulting distribution of extant pairs. The observed size differences for all comparisons in the fossil teeth were well within the variation observed in the extant African hominoid samples (p>0.05). In light of these results and other currently available cranial evidence, we suggest that the type specimens of Morotopithecus and Afropithecus are not different enough to support taxonomic distinction.

Africa, Eastern↗
PubMed2004

The diurnal rhythm of the intestinal transporters SGLT1 and PEPT1 is regulated by the feeding conditions in rats.

The intestinal Na(+)/glucose cotransporter 1 (SGLT1) and H(+)/peptide cotransporter 1 (PEPT1) play important roles in the absorption of carbohydrate and protein. Although they exhibit a diurnal rhythm in their expression and function, the factors responsible for this are unclear. In the present study, we examined the effects of various feeding conditions on the diurnal rhythm of intestinal SGLT1 and PEPT1. Rats were divided into 1 of 4 groups: group 1 was fed, group 2 was food deprived for 1-4 d, group 3 was food deprived for 4 d and then refed for 1 or 2 d, and group 4 was fed during the daytime (0900-1500 h) for 10 d. In fed rats, the SGLT1 protein level was significantly higher at 2000 h than at 0800 h. However, in rats deprived of food for 2-4 d, protein levels did not differ between 0800 and 2000 h. In contrast, the SGLT1 messenger RNA (mRNA) level was significantly higher at 2000 h than at 0800 h in rats deprived of food for 4 d. Refeeding for 2 d after 4 d of food deprivation returned the diurnal variation in SGLT1 and PEPT1 protein expressions to normal. Consuming food during the daytime only shifted the peaks of SGLT1 and PEPT1 mRNAs and protein expressions from the dark phase to the light phase. These findings suggest that food intake, rather than the light cycle, greatly affects the diurnal rhythm of SGLT1 and PEPT1 expressions.

Animals↗