Quantification of free mycophenolic acid by high-performance liquid chromatography-atmospheric pressure chemical ionisation tandem mass spectrometry

To facilitate the investigation of free mycophenolic acid concentrations we developed a high-performance liquid chromatography tandem mass spectrometry method using indomethacin as an internal standard. Free drug was isolated from plasma samples (500 mul) using ultrafiltration, The analytes were extracted from the ultrafiltrate (200 mul) using C-18 solid-phase extraction. Detection was by selected reactant monitoring of mycophenolic acid (m/z 318.9-->190.9) and the internal standard (m/z 356.0-->297.1) with an atmospheric pressure chemical ionisation interface. The total chromatographic analysis time was 12 min. The method was found to be linear over the range investigated, 2.5-200 mug/l (r>0.990, n=6). The relative recovery of the method for the control samples studied (7.5, 40.0 and 150 mug/l) ranged from 95 to 104%. The imprecision of the method, expressed in terms of intra- and inter-day coefficients of variation, was

Closely related Symbiodinium spp. differ in relative dominance in coral reef host communities across environmental, latitudinal and biogeographic gradients

The diversity and community structures of symbiotic dinoflagellates are described from reef invertebrates in southern and central provinces of the Great Barrier Reef (GBR), Australia, and Zamami Island, Okinawa, Japan. The symbiont assemblages from region to region were dominated by Clade C Symbiodinium spp. and consisted of numerous host-specific and/or rare types (specialists), and several types common to many hosts (generalists). Prevalence in the host community among certain host-generalist symbionts differed between inshore and offshore environments, across latitudinal (central versus southern GBR) gradients, and over wide geographic ranges (GBR versus Okinawa). One particular symbiont (C3h) from the GBR had a dramatic shift in dominance. Its prevalence ranged from being extremely rare, or absent on high-latitude reefs to dominating the scleractinian diversity on a mid-latitude inshore reef. These changes occurred among coral fauna whose larvae must acquire symbionts from environmental sources (horizontal symbiont acquisition). Such differences did not occur among 'vertical transmitters' such as Porites spp., Montipora spp. and pocilloporids (corals that directly transmit symbionts to their offspring) or among those hosts displaying 'horizontal acquisition', but that associate with specific symbionts. Most host-specialized types were found to be characteristic of a particular geographic region (i.e. Okinawa versus Central GBR versus Southern GBR). The mode of symbiont acquisition may play an important role in how symbiont composition may shift in west Pacific host communities in response to climate change. There is no indication that recent episodes of mass bleaching have provoked changes in host-symbiont combinations from the central GBR.

Smoking and relative body weight: An international perspective from the WHO MONICA project

Study objective-To investigate the magnitude and consistency of the associations between smoking and body mass index (BMI) in different populations. Design-A cross sectional study. Setting and participants-About 69000 men and women aged 35-64 years from 42 populations participating in the first WHO MONICA survey in the early and mid 1980s. Main restults-Compared to never smokers, regular smokers had significantly (p < 0.05) lower median BMI in 20 (men) and 30 (women) out of 42 populations (range -2.9 to 0.5kg/m(2)). There was no population in which smokers had a significantly higher BMI than never smokers. Among men, the association between leanness and smoking was less apparent in populations with relatively low proportions of regular smokers and high proportions of ex-smokers. Ex-smokers had significantly higher BMI than never smokers in 10 of the male populations but in women no consistent pattern was observed. Adjustment for socioeconomic status did not affect these results. Conclusions-Although in most populations the association between smoking and BMI is similar, the magnitude of this association may be affected by the proportions of smokers and ex-smokers in these populations.

Adjusting for fat-free mass in metabolic studies

in a recent publication, Eriksson et al. [1] explored the relationship between size at birth and resting metabolic rate and body composition in adulthood in a cohort of over 300 men and women. They reported an unexpected finding that people of both sexes who had a low birth weight also had a higher metabolic activity per unit muscle tissue. This conclusion was drawn from an analysis where resting metabolic rate (expressed as kcal/kg fat-free mass) in adulthood was examined relative to the birth weight of the subject. One explanation that they suggested was that the apparent increased activity of muscle tissue resulted from an increased sympathetic drive associated with low birth weight. There may be a less physiological reason for the findings of Eriksson et al. Whilst the data are not given specifically in the text, it can be seen clearly from Fig. 1 in the paper that the mean fat-free mass measured in adulthood increased, in both sexes, from the lightest birth weight group to the heaviest birth weight group when the cohort were divided into tertiles based on birth weight. The crux of the issue is that in many - indeed most - cases, expressing resting energy expenditure as kcal/kg fat-free mass does not totally adjust for fat-free mass [2 - 5], and a bias is introduced so that those who have a higher fat-free mass will tend to have a lower resting energy expenditure when expressed per kg fat-free mass. This bias found when expressing many physiological parameters relative to body size, body weight or body composition has long been known [6], and should be carefully considered by appropriate adjustment and hence analysis.

Quantification and stability of everolimus (SDZ RAD) in human blood by high-performance liquid chromatography-electrospray tandem mass spectrometry

We report here a validated method for the quantification of a new immunosuppressant drug, everolimus (SDZ RAD), using HPLC-tandem mass spectrometry. Whole blood samples (500 mul) were prepared by protein precipitation, followed by C-18 solid-phase extraction. Mass spectrometric detection was by selected reaction monitoring with an electrospray interface operating in positive ionization mode. The assay was linear from 0.5 to 100 mug/l (r(2) > 0.996, n = 9). The analytical recovery and inter-day imprecision, determined using whole blood quality control samples (n = 5) at 0.5, 1.2, 20.0, and 75.0 mug/l, was 100.3-105.4% and less than or equal to7.6%, respectively. The assay had a mean relative recovery of 94.8 +/- 3.8%. Extracted samples were stable for up to 24 h. Fortified everolimus blood samples were stable at -80 degreesC for at least 8 months and everolimus was found to be stable in blood when taken through at least three freeze-thaw cycles. The reported method provides accurate, precise and specific measurement of everolimus in blood over a wide analytical range and is currently supporting phase 11 and III clinical trials. (C) 2002 Elsevier Science B.V. All rights reserved.

Characterisation of multiple Caribbean ciguatoxins and congeners in individual specimens of horse-eye jack (Caranx latus) by high-performance liquid chromatography/mass spectrometry

We studied the variation in toxin profiles of purified extracts of 10 individual specimens and two pools of ciguateric Caranx latus. High-performance liquid chromatography/mass spectrometry (HPLC/MS) identified in all individual samples at least seven Caribbean ciguatoxins (C-CTXs) comprising C-CTX-1 and its epimer C-CTX-2 ([M + H](+) m/z 1141.58), and five new C-CTX congeners with pseudo-molecular ions at m/z 1141.58, 1143.60, 1157.57, 1159.58, and 1127.57. In some samples, additional C-CTX isomers were detected with [M + H](+) ions at m/z 1141.58 (two), 1143.60 (one) and 1157.57 (two). The two low-toxic pools contained only four to six ciguatoxins. The comparison in relative proportions of four different mass classes ([M + H](+) at m/z 1141, 1143, 1157 and 1127) showed that the group at m/z 1157 increased (2-20%) with flesh toxicity. More than 80% of group m/z 1141 comprised C-CTX-1, C-CTX-2 and their isomer C-CTX-1 a whose level in this group correlated with fish toxicity. Contrary to low-toxic fishes, high-risk specimens had C-CTX-1 levels

International images and mass media: The effects of media coverage on Canadians' perceptions of ethnic and race relations in Australia

Recently, there has been much speculation about the impact of international media coverage of Australia's position on Indigenous people, migrants and asylum seekers on other nations' images of Australia. In this experiment we examined whether there was any basis for such concerns by considering the short-term impact of negative TV coverage of Australians on Canadian viewers. A questionnaire provided baseline data on Canadian students' perceptions of Australians and Australian race relations. Four months later, the students were assigned to one of three conditions that varied media contact with Australians. Students viewed one of two television programs (about right-wing political independent, Pauline Hanson, and her emotive criticisms of Aborigines and Asian immigrants or about an ethnically-mixed group of young Australians and their positive sense of cultural identity), or they viewed no program (no contact control). Results indicated that both positive and negative media coverage of Australians affected Canadians' views of Australia in the short-term. In particular, negative coverage (of Hanson) promoted less favourable views of Australians and Australian race relations over time and relative to the positive media and no media control conditions. The media's role in shaping international images is discussed.

The relative importance of vascular structure and function in predicting cardiovascular events

OBJECTIVES We sought to assess the prognostic utility of brachial artery reactivity (BAR) in patients at risk of cardiovascular events. BACKGROUND Impaired flow-mediated vasodilation measured by BAR is a marker of endothelial dysfunction. Brachial artery reactivity is influenced by risk factors and is responsive to various pharmacological and other treatments. However, its prognostic importance is uncertain, especially relative to other predictors of outcome. METHODS A total of 444 patients were prospectively enrolled to undergo BAR and follow-up. These patients were at risk of cardiovascular events, based on the presence of risk factors or known or suspected cardiovascular disease. We took a full clinical history, performed BAR, and obtained carotid intima-media thickness (IMT) and left ventricular mass and ejection fraction. Patients were followed up for cardiovascular events and all-cause mortality. Multivariate Cox regression analysis was performed to assess the independent association of investigation variables on outcomes. RESULTS The patients exhibited abnormal BAR (5.2 +/- 6.1% [mean +/- SD]) but showed normal nitrate-mediated dilation (9.9 +/- 7.2%) and normal mean IMT (0.67 +/- 0.12 mm [average]). Forty-nine deaths occurred over the median follow-up period of 24 months (interquartile range 10 to 34). Patients in the lowest tertile group of BAR (<2%) had significantly more events than those in the combined group of highest and mid-tertiles (p = 0.029, log-rank test). However, mean IMT (rather than flow-mediated dilation) was the vascular factor independently associated with mortality, even in the subgroup (n = 271) with no coronary artery disease and low risk. CONCLUSIONS Brachial artery reactivity is lower in patients with events, but is not an independent predictor of cardiovascular outcomes in this cohort of patients. (C) 2004 by the American College of Cardiology Foundation.

Family average income and body mass index above the healthy weight range among urban and rural residents in regional Mainland China

Objective: To explore the relationship between family average income (FAI; an index of socio-economic status) and body mass index (BMI; a widely used, inexpensive indicator of weight status) above the healthy weight range in a region of Mainland China. Design: Population-based cross-sectional study, conducted between October 1999 and March 2000 on a sample of regular local residents aged 35 years or older who were selected by random cluster sampling. Setting: Forty-five administrative villages selected from three urban districts and two rural counties of Nanjing municipality, Mainland China, with a regional population of 5.6 million. Subjects: In total, 29 340 subjects participated; 67.7% from urban and 32.3% from rural areas; 49.8% male and 50.2% female. The response rate among eligible participants was 90.1%. Results: The proportion of participants classified as overweight was 30.5%, while 7.8% were identified as obese. After adjusting for possible confounding variables (age, gender, area of residence, educational level, occupational and leisure-time physical activity, daily vegetable consumption and frequency of red meat intake), urban participants were more likely to be overweight or obese relative to their rural counterparts, more women than men were obese, and participants in the lowest FAI tertile were the least likely to be above the healthy weight range. Conclusions: The proportion of adults with BMI above the healthy weight range was positively related to having a higher socio-economic status (indexed by FAI) in a regional Chinese population.

Measurement and stability of FTY720 in human whole blood by high-performance liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry

We report here a validated method for the quantification of a new immunosuppressant drug FTY720, using HPLC-tandem mass spectrometry. Whole blood samples (500 mu l) were subjected to liquid-liquid extraction, in the presence of an internal standard (Y-32919). Mass spectrometric detection was by selected reaction monitoring with an atmospheric pressure chemical ionization source in positive ionization mode (FTY720: m/z 308.3 -> 255.3). The assay was linear from 0.2 to 25 mu g/l (r(2) > 0.997, n = 5). The inter- and intra-day analytical recovery and imprecision for quality control samples (0.5, 7 and 15 mu g/l) were 95.8-103.2 and < 5.5%, respectively. At the lower limit of quantification (0.2 mu g/l) the interand intra-day analytical recovery was 99.0-102.8% with imprecision of < 7.6% (n = 5). The assay had a mean relative recovery of 100.5 +/- 5.8% (n = 15). Extracted samples were stable for 16 h. IFTY720 quality control samples were stable at room temperature for 16 h at 4 degrees C for at least 8 days and when taken through at least three freeze-thaw cycles. In conclusion, the method described displays analytical performance characteristics that are suitable for pharmacokinetic studies in humans. (c) 2006 Elsevier B.V. All rights reserved.

Does high intensity resistance training maintain bone mass during moderate weight loss in older overweight adults with type 2 diabetes

The aim was to investigate whether the addition of supervised high intensity progressive resistance training to a moderate weight loss program (RT+WLoss) could maintain bone mineral density (BMD) and lean mass compared to moderate weight loss (WLoss) alone in older overweight adults with type 2 diabetes. We also investigated whether any benefits derived from a supervised RT program could be sustained through an additional home-based program. This was a 12-month trial in which 36 sedentary, overweight adults aged 60 to 80 years with type 2 diabetes were randomized to either a supervised gymnasium-based RT+WLoss or WLoss program for 6 months (phase 1). Thereafter, all participants completed an additional 6-month home-based training without further dietary modification (phase 2). Total body and regional BMD and bone mineral content (BMC), fat mass (FM) and lean mass (LM) were assessed by DXA every 6 months. Diet, muscle strength (1-RM) and serum total testosterone, estradiol, SHBG, insulin and IGF-1 were measured every 3 months. No between group differences were detected for changes in any of the hormonal parameters at any measurement point. In phase 1, after 6 months of gymnasium-based training, weight and FM decreased similarly in both groups (P < 0.01), but LM tended to increase in the RT+WLoss (n=16) relative to the WLoss (n = 13) group [net difference (95% CI), 1.8% (0.2, 3.5), P < 0.05]. Total body BMD and BMC remained unchanged in the RT+WLoss group, but decreased by 0.9 and 1.5%, respectively, in the WLoss group (interaction, P < 0.05). Similar, though non-significant, changes were detected at the femoral neck and lumbar spine (L2-L4). In phase 2, after a further 6 months of home-based training, weight and FM increased significantly in both the RT+WLoss (n = 14) and WLoss (n = 12) group, but there were no significant changes in LM or total body or regional BMD or BMC in either group from 6 to 12 months. These results indicate that in older, overweight adults with type 2 diabetes, dietary modification should be combined with progressive resistance training to optimize the effects on body composition without having a negative effect on bone health.

Direct numerical simulation of turbulent flow and mass transfer around a rotating circular cylinder

Turbulent flow around a rotating circular cylinder has numerous applications including wall shear stress and mass-transfer measurement related to the corrosion studies. It is also of interest in the context of flow over convex surfaces where standard turbulence models perform poorly. The main purpose of this paper is to elucidate the basic turbulence mechanism around a rotating cylinder at low Reynolds numbers to provide a better understanding of flow fundamentals. Direct numerical simulation (DNS) has been performed in a reference frame rotating at constant angular velocity with the cylinder. The governing equations are discretized by using a finite-volume method. As for fully developed channel, pipe, and boundary layer flows, a laminar sublayer, buffer layer, and logarithmic outer region were observed. The level of mean velocity is lower in the buffer and outer regions but the logarithmic region still has a slope equal to the inverse of the von Karman constant. Instantaneous flow visualization revealed that the turbulence length scale typically decreases as the Reynolds number increases. Wavelet analysis provided some insight into the dependence of structural characteristics on wave number. The budget of the turbulent kinetic energy was computed and found to be similar to that in plane channel flow as well as in pipe and zero pressure gradient boundary layer flows. Coriolis effects show as an equivalent production for the azimuthal and radial velocity fluctuations leading to their ratio being lowered relative to similar nonrotating boundary layer flows.

Subject/Object Asymmetry in the Comprehension of English Relative Clauses by Japanese Learners of English

While a number of studies have shown that object-extracted relative clauses are more difficult to understand than subject-extracted counterparts for second language (L2) English learners (e.g., Izumi, 2003), less is known about why this is the case and how they process these complex sentences. This exploratory study examines the potential applicability of Gibson's (1998, 2000) Syntactic Prediction Locality Theory (SPLT), a theory proposed to predict first language (L1) processing difficulty, to L2 processing and considers whether the theory might also account for the processing difficulties of subject- and object-extracted relative clauses encountered by L2 learners. Results of a self-paced reading time experiment from 15 Japanese learners of English are mainly consistent with the reading time profile predicted by the SPLT and thus suggest that the L1 processing theory might also be able to account for L2 processing difficulty.

Evaluation of multifrequency bioelectrical impedance data for predicting lean tissue mass in beef cattle

Multifrequency bioimpedance analysis has the potential to provide a non-invasive technique for determining body composition in live cattle. A bioimpedance meter developed for use in clinical medicine was adapted and evaluated in 2 experiments using a total of 31 cattle. Prediction equations were obtained for total body water, extracellular body water, intracellular body water, carcass water and carcass protein. There were strong correlations between the results obtained through chemical markers and bioimpedance analysis when determined in cattle that had a wide range of liveweights and conditions. The r(2) values obtained were 0.87 and 0.91 for total body water and extracellular body water respectively. Bioimpedance also correlated with carcass water, measured by chemical analysis (r(2) = 0.72), but less well with carcass protein (r(2) = 0.46). These correlations were improved by inclusion of liveweight and sex as variables in multiple regression analysis. However, the resultant equations were poor predictors of protein and water content in the carcasses of a group of small underfed beef cattle, that had a narrow range of liveweights. In this case, although there was no statistical difference between the predicted and measured values overall, bioimpedance analysis did not detect the differences in carcass protein between the 2 groups that were apparent following chemical analysis. Further work is required to determine the sensitivity of the technique in small underfed cattle, and its potential use in heavier well fed cattle close to slaughter weight.

Bioimpedance spectrometry in the determination of body water compartments: Accuracy and clinical significance

Bioelectrical impedance analysis (BIA) offers the potential for a simple, portable and relatively inexpensive technique for the in vivo measurement of total body water (TBW). The potential of BIA as a technique of body composition analysis is even greater when one considers that body water can be used as a surrogate measure of lean body mass. However, BIA has not found universal acceptance even with the introduction of multi-frequency BIA (MFBIA) which, potentially, may improve the predictive accuracy of the measurement. There are a number of reasons for this lack of acceptance, although perhaps the major reason is that no single algorithm has been developed which can be applied to all subject groups. This may be due, in part, to the commonly used wrist-to-ankle protocol which is not indicated by the basic theory of bioimpedance, where the body is considered as five interconnecting cylinders. Several workers have suggested the use of segmental BIA measurements to provide a protocol more in keeping with basic theory. However, there are other difficulties associated with the application of BIA, such as effects of hydration and ion status, posture and fluid distribution. A further putative advantage of MFBIA is the independent assessment not only of TBW but also of the extracellular fluid volume (ECW), hence heralding the possibility of,being able to assess the fluid distribution between these compartments. Results of studies in this area have been, to date, mixed. Whereas strong relationships of impedance values at low frequencies with ECW, and at high frequencies with TBW, have been reported, changes in impedance are not always well correlated with changes in the size of the fluid compartments (assessed by alternative and more direct means) in pathological conditions. Furthermore, the theoretical advantages of Cole-Cole modelling over selected frequency prediction have not always been apparent. This review will consider the principles, methodology and applications of BIA. The principles and methodology will,be considered in relation to the basic theory of BIA and difficulties experienced in its application. The relative merits of single and multiple frequency BIA will be addressed, with particular attention to the latter's role in the assessment of compartmental fluid volumes. (C) 1998 Elsevier Science Ltd. All rights reserved.