Fine structure of the diamagnetic cavity boundary in comet Halley

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95105/1/jgra16786.pd

Cheese whey-induced high-cell-density production of recombinant proteins in Escherichia coli

BACKGROUND: Use of lactose-rich concentrates from dairy processes for the induction of recombinant gene's expression has not received much attention although they are interesting low cost substrates for production of recombinant enzymes. Applicability of dairy waste for induction of recombinant genes in Escherichia coli was studied. Clones expressing Lactobacillus phage muramidase and Lactobacillus alcohol dehydrogenase were used for the experiments. RESULTS: Shake flask cultivations in mineral salt medium showed that cheese whey or deproteinised whey induced gene expression as efficiently as IPTG (isopropyl-β-D-thiogalactopyranoside) or pure lactose. Addition of yeast extract or proteolytically degraded whey proteins did not improve the recombinant protein yield. In contrast, addition of yeast extract to the well-balanced mineral salt medium decreased the product yield. Feeding with glycerol provided sufficient amount of easily assimilable carbon source during the induction period without preventing lactose intake and induction by lactose. High-cell-density fed-batch cultivations showed that product yields comparable to IPTG-induction can be achieved by feeding bacteria with a mixture of glycerol and concentrated whey permeate during the induction. CONCLUSION: Whey and concentrated whey permeate can be applied as an alternative inducer in recombinant high-cell-density fed-batch fermentations. The yield of the recombinant product was comparable to fermentations induced by IPTG. In low-cell-density shake flask experiments the yield was higher with whey or whey permeate than with IPTG

Age effect on retina and optic disc normal values

Purpose: To investigate retinal thickness and optic disc parameters by the Retinal Thickness Analyzer (RTA) glaucoma program in older normal subjects and to determine any age effect. Methods: Subjects over 40 years of age without any prior history of eye diseases were recruited. Only subjects completely normal on clinical ophthalmologic examination and on visual field testing by Humphrey Field Analyzer (HFA) using the SITA 24-2 program were included. A total of 74 eyes from 74 subjects with even age distribution over the decades were enrolled and underwent topographic measurements of the posterior pole and of the optic disc by RTA. The `glaucoma full' program in software version 4.11B was applied. Results: Mean patient age was 59.9 +/- 10.3 years with a range from 40 to 80 years. The only parameter intraocular pressure (IOP) correlated with was retinal posterior pole asymmetry (r=0.27, p=0.02). IOP itself increased significantly with age (r=0.341, p=0.003). Mean defect and pattern standard deviation of the HFA did not correlate with any of the retinal or optic disc measurements. Increasing age correlated significantly with some of the morphologic measurements of the RTA: decreasing perifoveal minimum thickness (r=-0.258, p=0.026), increased cup-to-disc area ratio (r=0.302, p=0.016) and increased cup area (r=0.338 p=0.007). Conclusions: An age effect exists for some of the retina and optic disc measurements obtained by the RTA. Copyright (C) 2005 S. Karger AG, Basel

Persistent detwinning of iron pnictides by small magnetic fields

Our comprehensive study on EuFe$_2$As$_2$ reveals a dramatic reduction of magnetic detwinning fields compared to other AFe$_2$As$_2$ (A = Ba, Sr, Ca) iron pnictides by indirect magneto-elastic coupling of the Eu$^{2+}$ ions. We find that only 0.1T are sufficient for persistent detwinning below the local Eu$^{2+}$ ordering; above $T_\text{Eu}$ = 19K, higher fields are necessary. Even after the field is switched off, a significant imbalance of twin domains remains constant up to the structural and electronic phase transition (190K). This persistent detwinning provides the unique possibility to study the low temperature electronic in-plane anisotropy of iron pnictides without applying any symmetrybreaking external force.Comment: accepted by Physical Review Letter

Right ventricular responses to CPAP therapy in obstructive sleep apnoea: CMR analysis of the MOSAIC randomised trial

Effects of continuous positive airway pressure (CPAP) on right ventricular (RV) function in patients with untreated mild-to-moderate obstructive sleep apnea (OSA) are unclear. In this exploratory analysis of cardiac magnetic resonance (CMR)-derived indices of RV function in patients with minimally symptomatic OSA from the MOSAIC randomized control trial we found no effect of CPAP on RV CMR parameters. In those with lower RV ejection fraction and higher RV end-diastolic volume (EDV) at baseline, CPAP treatment appeared to improve RV function with a significant reduction in both RV EDV and RV end-systolic volume although between-group effects were not observed. These data suggest potential merit in a larger randomized study of CPAP in patients with mild-to-moderate OSA and a greater breadth of RV dysfunction

A Hot Helium Plasma in the Galactic Center Region

Recent X-ray observations by the space mission Chandra confirmed the astonishing evidence for a diffuse, hot, thermal plasma at a temperature of 9. $10^7$ K (8 keV) found by previous surveys to extend over a few hundred parsecs in the Galactic Centre region. This plasma coexists with the usual components of the interstellar medium such as cold molecular clouds and a soft (~0.8 keV) component produced by supernova remnants, and its origin remains uncertain. First, simple calculations using a mean sound speed for a hydrogen-dominated plasma have suggested that it should not be gravitationally bound, and thus requires a huge energy source to heat it in less than the escape time. Second, an astrophysical mechanism must be found to generate such a high temperature. No known source has been identified to fulfill both requirements. Here we address the energetics problem and show that the hot component could actually be a gravitationally confined helium plasma. We illustrate the new prospects this opens by discussing the origin of this gas, and by suggesting possible heating mechanisms.Comment: 9 pages, accepted for publication in APJ

Respiratory insufficiency related to copd accelerates systemic inflammation, under-nutrition, and angiogenesis in esophageal malignancies

A number of esophageal cancer patients suffer from respiratory insufficiency due to the coexistence of chronic obstructive pulmonary disease (COPD). Aim: To test the hypothesis that COPD-related systemic hypoxemia may result in accelerated inflammation, malnutrition, and angiogenesis in esophageal cancer patients. Methods: Serum levels of C-reactive protein (CRP), albumin, transferrin, interleukin-1, interleukin-6, interleukin-8, TNF- a, platelet-derived growth factor (PDGF-BB), and midkine and patient BMI and weight-loss rate were determined and compared with blood oxygenation status (pO2, SaO2) in 35 esophageal cancer patients and 42 controls. Results: The incidence of cachexia tended to be higher in patients with systemic hypoxemia (67% vs 40%, p = 0.169). Mean SaO2 level was also significantly decreased in cachectic patients (90.3 vs 93.3%, p = 0.026) and pO2 exhibited a similar trend (58.0 vs 63.4 mmHg, p = 0.120). Transferrin (234 vs 316 mg/dl, p = 0.005) and albumin (31.9 vs 37.1 mg/dl, p = 0.002) concentrations were reduced and CRP was elevated (129.9 vs 54.7 mg/l, p = 0.004) in hypoxemic patients and correlated with pO2 (r = 0.47, p = 0.016; r = 0.48, p = 0.012; r = –0.37, p = 0.064) and SaO2 (r = 0.52, p = 0.006; r = 0.53, p = 0.006; r = –0.40, p = 0.042). Interleukin-6 (9.97 vs 2.21 pg/ml, p = 0.005) and midkine (2101 vs 944 pg/ml, p < 0.001) were elevated and PDGF-BB was decreased (12.2 vs 17.3 pg x 10-6/PLT, p = 0.014) in hypoxemic compared with normoxemic patients. Interleukin-6 and midkine negatively correlated with pO2 (r = –0.44, p = 0.016; r = –0.42, p = 0.011) and SaO2 (r = –0.54, p = 0.003; r = –0.57, p < 0.0001) and PDGF-BB correlated positively (r = 0.53, p = 0.003; r = 0.44, p = 0.020). Interleukin-8 level was affected by pO2 (r = -0.55, p = 0.015) and SaO2 (r = –0.55, p = 0.018) only in hypoxemic patients. Conclusions: COPD-related systemic hypoxemia negatively affects the status of esophageal cancer patients by accelerating inflammation, under-nutrition, and angiogenesis.Многие больные раком пищевода страдают от респираторной недостаточности из-за развития хронического обструктивного легочного заболевания (COPD). Цель: Проверить гипотезу о возможной связи системной гипоксемии, ассоциированной с COPD, с усилением воспалительных процессов, истощением и ангиогенезом у больных раком пищевода. Методы: у 35 больных раком пищевода и 42 здоровых доноров определяли уровень CRP, альбумина, трансферина, интерлейкина-1, интерлейкина-6, интерлейкина-8, TNF-α, PDGF-BB и мидкина в сыворотке крови, показатели BMI и потери веса больных, а также показатели уровня оксигенации крови (pO2 , SaO2 ). Результаты: частота возникновения кахексии была выше у больных с системной гипоксемией (67 против 40%, p = 0,169). Средний уровень SaO2 был также значительно снижен у больных с кахексией (90,3 против 93,3%, p = 0,026), с той же тенденцией и для уровня pO2 (58,0 против 63,4 mmHg, p = 0,120). Концентрации трансферина (234 против 316 мг/дл, p = 0,005) и альбумина (31,9 против 37,1 мг/дл, p = 0,002) были снижены, CRP повышен (129,9 против 54,7 мг/л, p = 0,004) у гипоксемических пациентов, что кореллировало с показателями pO2 (r = 0,47, p = 0,016; r = 0,48, p = 0,012; r = –0,37, p = 0,064) и SaO2 (r = 0,52, p = 0,006; r = 0,53, p = 0,006; r = –0,40, p = 0,042). Уровень интерлейкина-6 (9,97 против 2,21 pg/ml, p = 0,005) и мидкина (2101 против 944 pg/ml, p < 0,001) был также повышен, а уровень PDGF-BB понижен (12,2 против 17,3 pg × 10-6/PLT, p = 0,014) у гипоксемических больных по сравнению с показателями при нормоксемии. Уровни интерлейкина-6 и мидкина негативно кореллировали с показателями pO2 (r = –0,44, p = 0,016; r = –0,42, p = 0,011) и SaO2 (r = –0,54, p = 0,003; r = –0,57, p < 0,0001) и позитивно — с PDGF-BB (r = 0,53, p = 0,003; r = 0,44, p = 0,020). На уровень интерлейкина-8 влияли pO2 (r = –0,55, p = 0,015) и SaO2 (r = –0,55, p = 0,018) только у больных с гипоксемией. Выводы: ассоциированная с COPD системная гипоксемия негативно влияет на состояние больных раком пищевода за счет ускорения воспалительных процессов, истощения и ангиогенез

Measuring inorganic phosphate and intracellular pH in the healthy and hypertrophic cardiomyopathy hearts by in vivo 7T 31P-cardiovascular magnetic resonance spectroscopy.

BACKGROUND: Cardiovascular phosphorus MR spectroscopy (31P-CMRS) is a powerful tool for probing energetics in the human heart, through quantification of phosphocreatine (PCr) to adenosine triphosphate (ATP) ratio. In principle, 31P-CMRS can also measure cardiac intracellular pH (pHi) and the free energy of ATP hydrolysis (ΔGATP). However, these require determination of the inorganic phosphate (Pi) signal frequency and amplitude that are currently not robustly accessible because blood signals often obscure the Pi resonance. Typical cardiac 31P-CMRS protocols use low (e.g. 30°) flip-angles and short repetition time (TR) to maximise signal-to-noise ratio (SNR) within hardware limits. Unfortunately, this causes saturation of Pi with negligible saturation of the flowing blood pool. We aimed to show that an adiabatic 90° excitation, long-TR, 7T 31P-CMRS protocol will reverse this balance, allowing robust cardiac pHi measurements in healthy subjects and patients with hypertrophic cardiomyopathy (HCM). METHODS: The cardiac Pi T1 was first measured by the dual TR technique in seven healthy subjects. Next, ten healthy subjects and three HCM patients were scanned with 7T 31P-MRS using long (6 s) TR protocol and adiabatic excitation. Spectra were fitted for cardiac metabolites including Pi. RESULTS: The measured Pi T1 was 5.0 ± 0.3 s in myocardium and 6.4 ± 0.6 s in skeletal muscle. Myocardial pH was 7.12 ± 0.04 and Pi/PCr ratio was 0.11 ± 0.02. The coefficients of repeatability were 0.052 for pH and 0.027 for Pi/PCr quantification. The pH in HCM patients did not differ (p = 0.508) from volunteers. However, Pi/PCr was higher (0.24 ± 0.09 vs. 0.11 ± 0.02; p = 0.001); Pi/ATP was higher (0.44 ± 0.14 vs. 0.24 ± 0.05; p = 0.002); and PCr/ATP was lower (1.78 ± 0.07 vs. 2.10 ± 0.20; p = 0.020), in HCM patients, which is in agreement with previous reports. CONCLUSION: A 7T 31P-CMRS protocol with adiabatic 90° excitation and long (6 s) TR gives sufficient SNR for Pi and low enough blood signal to permit robust quantification of cardiac Pi and hence pHi. Pi was detectable in every subject scanned for this study, both in healthy subjects and HCM patients. Cardiac pHi was unchanged in HCM patients, but both Pi/PCr and Pi/ATP increased that indicate an energetic impairment in HCM. This work provides a robust technique to quantify cardiac Pi and pHi.This work was funded by a Sir Henry Dale Fellowship from the Wellcome Trust and the Royal Society (grant #098436/Z/12/B to C.T.R.) and by an Erwin Schrödinger Fellowship from the Austrian Science Fund (grant #J4043). Authors also acknowledge the support of the NIHR Oxford Biomedical Research Centre and the Oxford British Heart Foundation Centre of Research Excellence. The support of the Slovak Grant Agency VEGA (grant #2/0001/17) and APVV (grant #15-0029) is also acknowledged