The relationship between pulse pressure with plasma PCSK9 and interleukin-6 among patients with acute ischemic stroke and dyslipidemia

BACKGROUND AND PURPOSE

A high plasma concentration of proprotein convertase subtilisin/kexin type 9 is characteristic of a prothrombotic state in cardiovascular diseases. Elevated inflammatory markers, such as interleukin-6, are associated with worse outcomes after ischemic stroke. We aimed to study the role of plasma PCSK9 and IL-6 in acute ischemic stroke with dyslipidemia.

METHODS

We divided 123 enrolled patients with first-ever acute ischemic stroke into normotensive and high blood pressure groups and further into high and low pulse pressure subgroups. Clinical characteristics and inflammatory and metabolic parameters, including plasma PCSK9 and IL-6, were recorded.

RESULTS

After the analysis of the normotensive and BP groups, there were positive correlations between PP and carotid stenosis (P = 0.031) and plaque numbers (P = 0.013) and between National Institute of Health Stroke Scale scores (P = 0.019) and carotid stenosis severity (P = 0.021) and resistance index (P = 0.04). There was a significant association between plasma cholesterol and PCSK9 (P = 0.044) in the low PP subgroup and IL-6 (P = 0.042) in the high PP subgroup.

CONCLUSIONS

Our findings indicated that plasma PCSK9 levels were associated with the low PP subgroup, while IL-6 was associated with the high PP subgroup. Dyslipidemia control is also necessary for those who had a stroke and who have high PP. Further investigation to assess the role of PCSK9 and IL-6 in patients with stroke is required for early treatment and secondary prevention.

Improved Constraints on Primordial Gravitational Waves using Planck, WMAP, and BICEP/Keck Observations through the 2018 Observing Season

We present results from an analysis of all data taken by the BICEP2, Keck Array, and BICEP3 CMB polarization experiments up to and including the 2018 observing season. We add additional Keck Array observations at 220 GHz and BICEP3 observations at 95 GHz to the previous 95/150/220  GHz dataset. The Q/U maps now reach depths of 2.8, 2.8, and 8.8  μK_{CMB} arcmin at 95, 150, and 220 GHz, respectively, over an effective area of ≈600 square degrees at 95 GHz and ≈400 square degrees at 150 and 220 GHz. The 220 GHz maps now achieve a signal-to-noise ratio on polarized dust emission exceeding that of Planck at 353 GHz. We take auto- and cross-spectra between these maps and publicly available WMAP and Planck maps at frequencies from 23 to 353 GHz and evaluate the joint likelihood of the spectra versus a multicomponent model of lensed ΛCDM+r+dust+synchrotron+noise. The foreground model has seven parameters, and no longer requires a prior on the frequency spectral index of the dust emission taken from measurements on other regions of the sky. This model is an adequate description of the data at the current noise levels. The likelihood analysis yields the constraint r_{0.05}<0.036 at 95% confidence. Running maximum likelihood search on simulations we obtain unbiased results and find that σ(r)=0.009. These are the strongest constraints to date on primordial gravitational waves.

38 Dementia, Apoe and COVID-19 Severity

Introduction

During the COVID-19 pandemic, pre-existing dementia was associated with a 3x increase in risk of hospitalisation and (25.6%) of COVID-19 related deaths had dementia. However, it is unclear whether people living with dementia are at higher risk of COVID-19 due to dementia or whether there may be a biologically plausible link between dementia and COVID-19. The ApoE e4 allele is highly associated with dementia. We aimed to test the COVID-19 risk associated with dementia and the association between ApoE e4e4 allele and COVID-19 with the aim of clarifying biological vulnerability.

Methods

UK Biobank (England) participants baseline (2006 to 2010), plus secondary care data to 2017. Separate analysis tested dementia and ApoE genotype association with COVID-19 status (16th March-31st May 2020) or mortality (to March 31, 2020, plus incomplete deaths from April, 2020) in logistic models, adjusted for demographics and technical covariates.

Results

In 269,070 participants aged 65+, including 507(0.2%) hospitalized COVID-19 patients, those with pre-existing dementia were at increased risk of being hospitalized for COVID-19 (OR = 3.50 95% CI 1.93 to 6.34) and also for COVID-19 and death (OR = 7.30 95% CI 3.28–16.21). In 375,689 European-ancestry UKB participants, ApoE e4e4 homozygotes were more likely to be COVID-19 test positives (reaching genome-wide significance: OR = 2.24, 95% CI:1.72–2.93, p = 3.24 × 10–9) and of mortality with test-confirmed COVID-19 (OR = 4.29, 95% CI: 2.38–7.72, p = 1.22 × 10–6), compared to e3e3s homozygotes. The associations were little changed in subsets of participants who were free of diseases associated with ApoE e4 and COVID-19 severity.

Conclusion

Dementia was found to be disproportionally common in older adults who develop severe COVID-19. We have shown a plausible genetic pathway of increased COVID-19 risk with dementia, therefore suggesting that the positive association between dementia and COVID-19 is not just the result of high cases of COVID-19 in care homes.

Association of cyclophilin A level and pulse pressure in predicting recurrence of cerebral infarction

Cyclophilin A (CypA), secreted from vascular smooth muscle cells and inflammatory cells in response to oxidative stress, promotes vascular atherosclerosis and development of carotid stenosis. Increased concentration of plasma CypA in acute cerebral infarction was demonstrated clinically. The primary aim of this study was to investigate the prognostic impact between CypA level and outcome in patients with acute ischemic stroke. Admission serum CypA concentrations were detected in 66 acute cerebral infarction patients and in 52 healthy individuals. Inflammatory biomarkers, including high-sensitivity C-reactive protein, adhesion molecules, interleukins, and matrix-metalloproteases, were also assessed. We also examined the relationship between plasma biomarkers, blood pressure (BP), pulse pressure, the carotid artery velocity, the prognostic assessment with modified Rankin scale, and stroke recurrence. Plasma CypA concentration was higher on the first day of hospitalization in the high BP stroke group than in normal BP stroke group, which was statistically significant, which was observed even in the third month and sixth month follow-up outpatient periods. For stroke recurrence prediction, there was an important association between the higher (>60) pulse pressure on the seventh day of hospitalization and CypA level on the third month and sixth month follow-up outpatient periods. Our study revealed higher circulating serum levels of CypA in the hypertensive stroke group than in the non-hypertensive stroke group. We expect that elevated plasma CypA level and raised pulse pressure during hospitalization to become valuable biomarkers in predicting stroke recurrence in the sixth month assessment of acute cerebral infarction.

Cyclophilin A: A Predictive Biomarker of Carotid Stenosis in Cerebral Ischemic Stroke

BACKGROUND

Cyclophilin A plays a pathogenic role in the development and progression of atherosclerosis, which can be assessed by measuring carotid intima-media thickness. The primary aim of this study was to examine the interaction between plasma Cyclophilin A level and carotid intima-media thickness in patients with acute ischemic stroke.

METHOD

Plasma concentration of Cyclophilin A was measured on admission in 66 consecutive patients who had been hospitalized for acute cerebral stroke and in 52 case-control subjects without a history of acute stroke. Subjects in both groups also underwent ultrasound B-mode imaging to measure the mean and maximum intima-media thickness of the carotid artery. Inflammatory biomarkers including high-sensitivity C-reactive protein and fibrinogen were also assessed.

RESULTS

We found that the plasma concentration of Cyclophilin A was significantly higher in patients with acute ischemic stroke (p = 0.042). Increased Cyclophilin A was also correlated with carotid intima-media thickness in the patient group (p < 0.001). Among the risk factors for cerebral stroke examined in this study, only hypertension was significantly associated with plasma Cyclophilin A level.

CONCLUSION

Increased plasma Cyclophilin A levels might be involved in the pathophysiology of acute ischemic stroke and Cyclophilin A might serve as a biomarker in risk assessment of acute stroke patients.

Cyclophilin A and CD147 associate with progression of diabetic nephropathy

To find the associations of circulating cyclophilin A (CyP A) and CD147/EMMPRIN with renal outcomes in type 2 diabetes patients and possible pathogenesis involved. Total 131 patients were recruited since 2004. Glycated hemoglobin, blood glucose and urine albumin-creatinine ratio levels at baseline and every 3 months were measured. Plasma CyP A and CD147 were also measured at baseline. Patients were divided into two groups based upon the median level of the baseline plasma CyP A value: < 93.64 ng/mL (group A, n = 65), ≥ 93.64 ng/mL (group B, n = 66). The estimated glomerular filtration rate was calculated at each follow-up visit. Besides, mitochondrial function assay by cellular mitochondrial energy utility was studied when cells were exposed to glucose or exogenous CyP A or both. Multivariate analysis, using median level (93.64) ng/mL as the cut-off value, revealed that circulating CyP A and CD147 levels at baseline were associated with the baseline estimated glomerular filtration rate (eGFR) (p = .042 and p = .001 separately) in cross-sectional analysis. Longitudinally, higher baseline plasma CyP A level was also correlated to a rapid decline in eGFR (p = .016). The results were also significant when using the continuous plasma CyP A level (p = .003). In cells exposed to glucose, results of oxygen consumption rate (OCR) showed a significant reduction in basal respiration, maximal respiration and ATP production. Depressed OCR further occurred when incubated with both of CyP A and glucose. Plasma CyP A and CD147 can serve as indicators of renal disease progression in type 2 diabetes patients.

Constraints on Primordial Gravitational Waves Using Planck, WMAP, and New BICEP2/Keck Observations through the 2015 Season

We present results from an analysis of all data taken by the bicep2/Keck CMB polarization experiments up to and including the 2015 observing season. This includes the first Keck Array observations at 220 GHz and additional observations at 95 and 150 GHz. The Q and U maps reach depths of 5.2, 2.9, and 26  μK_{CMB} arcmin at 95, 150, and 220 GHz, respectively, over an effective area of ≈400 square degrees. The 220 GHz maps achieve a signal to noise on polarized dust emission approximately equal to that of Planck at 353 GHz. We take auto and cross spectra between these maps and publicly available WMAP and Planck maps at frequencies from 23 to 353 GHz. We evaluate the joint likelihood of the spectra versus a multicomponent model of lensed-ΛCDM+r+dust+synchrotron+noise. The foreground model has seven parameters, and we impose priors on some of these using external information from Planck and WMAP derived from larger regions of sky. The model is shown to be an adequate description of the data at the current noise levels. The likelihood analysis yields the constraint r_{0.05}<0.07 at 95% confidence, which tightens to r_{0.05}<0.06 in conjunction with Planck temperature measurements and other data. The lensing signal is detected at 8.8σ significance. Running a maximum likelihood search on simulations we obtain unbiased results and find that σ(r)=0.020. These are the strongest constraints to date on primordial gravitational waves.

Prevention of complications in glycogen storage disease type Ia with optimization of metabolic control

Prior to 1971, type Ia glycogen storage disease was marked by life-threatening hypoglycemia, lactic acidosis, severe failure to thrive, and developmental delay. With the introduction of continuous feeds in the 1970s and cornstarch in the 1980s, the prognosis improved, but complications almost universally developed. Changes in the management of type Ia glycogen storage disease have resulted in improved metabolic control, and this manuscript reviews the increasing evidence that complications can be delayed or prevented with optimal metabolic control as previously was seen in diabetes.

Development of separation techniques for analysis of Nb-94 in radwaste samples

A chemical separation technique for removing interfering gamma-ray radionuclides by combined precipitation of Nb pentoxide and anion exchange was proposed, thereby allowing detection of trace ⁹⁴Nb in low-level radwastes. The detection limit for ⁹⁴Nb was improved by a factor of 10-10³, and the scaling factor (⁹⁴Nb/⁶⁰Co) of the radwastes was estimated to be less than 10^-5. This technique can be used for low-level radwaste classification and power reactor decommissioning.

Depleted Leukocyte Mitochondrial DNA Copy Number Correlates With Unfavorable Left Ventricular Volumetric and Spherical Shape Remodeling in Acute Myocardial Infarction After Primary Angioplasty

BACKGROUND

Left ventricular (LV) shape influences LV systolic function. It is possible to assess LV shape using 3-D echocardiography sphericity index (SI). Maintaining mitochondrial DNA copy number (MCN) is important for preserving mitochondrial function and LV systolic function after acute myocardial infarction (AMI). Information is limited, however, regarding the relationship between leukocyte MCN and the subsequent change in LV shape after AMI.Methods and Results:Fifty-five AMI patients undergoing primary angioplasty were recruited. Plasma MCN was measured before primary angioplasty using quantitative polymerase chain reaction. 3-D echocardiography measurement of SI was performed at baseline, and at 1-, 3-, and 6-month follow-up. AMI subjects with MCN lower than the median had a higher 6-month SI and LV volume compared with those with higher MCN. Baseline echocardiographic parameters were similar between the 2 groups. MCN was negatively correlated with 3- and 6-month SI, and 3- and 6-month LV volume. On multiple linear regression analysis, baseline plasma MCN could predict LV SI and LV volume at 6 months after primary angioplasty for AMI, even after adjusting for traditional prognostic factors.

CONCLUSIONS

In AMI patients, higher plasma leukocyte MCN at baseline was associated with favorable LV shape and remodeling at 6-month follow-up. Plasma leukocyte MCN may provide a novel prognostic biomarker for LV remodeling after AMI.

High plasma coenzyme Q10 concentration is correlated with good left ventricular performance after primary angioplasty in patients with acute myocardial infarction

Exogenous administration of coenzyme Q10 (CoQ10) has been shown in experimental models to have a protective effect against ischemia-reperfusion injury. However, it is unclear whether follow-up plasma CoQ10 concentration is prognostic of left ventricular (LV) performance after primary balloon angioplasty in patients with acute ST segment elevation myocardial infarction (STEMI).We prospectively recruited 55 patients with STEMI who were treated with primary coronary balloon angioplasty. Plasma CoQ10 concentrations were measured before primary angioplasty (baseline) and 3 days, 7 days, and 1 month after STEMI using high-performance liquid chromatography. Echocardiography was performed at baseline and at 6-month follow-up. The control group comprised 54 healthy age- and sex-matched volunteers.Serial circulating CoQ10 concentrations significantly decreased with time in the STEMI group. The LV ejection fraction at 6-month follow-up positively correlated with the 1-month plasma CoQ10 tertile. Higher plasma CoQ10 concentrations at 1 month were associated with favorable LV remodeling and systolic function 6 months after STEMI. Multiple linear regression analysis showed that changes in CoQ10 concentrations at 1-month follow-up were predictive of LV systolic function 6 months after STEMI. Changes in CoQ10 concentrations correlated negatively with baseline oxidized low-density lipoprotein and fibrinogen concentrations and correlated positively with leukocyte mitochondrial copy number at baseline.Patients with STEMI who had higher plasma CoQ10 concentrations 1 month after primary angioplasty had better LV performance at 6-month follow-up. In addition, higher plasma CoQ10 concentration was associated with lower grade inflammatory and oxidative stress status. Therefore, plasma CoQ10 concentration may serve as a novel prognostic biomarker of LV systolic function after revascularization therapy for acute myocardial infarction.

Improved Constraints on Cosmology and Foregrounds from BICEP2 and Keck Array Cosmic Microwave Background Data with Inclusion of 95 GHz Band

We present results from an analysis of all data taken by the BICEP2 and Keck Array cosmic microwave background (CMB) polarization experiments up to and including the 2014 observing season. This includes the first Keck Array observations at 95 GHz. The maps reach a depth of 50 nK deg in Stokes Q and U in the 150 GHz band and 127 nK deg in the 95 GHz band. We take auto- and cross-spectra between these maps and publicly available maps from WMAP and Planck at frequencies from 23 to 353 GHz. An excess over lensed ΛCDM is detected at modest significance in the 95×150 BB spectrum, and is consistent with the dust contribution expected from our previous work. No significant evidence for synchrotron emission is found in spectra such as 23×95, or for correlation between the dust and synchrotron sky patterns in spectra such as 23×353. We take the likelihood of all the spectra for a multicomponent model including lensed ΛCDM, dust, synchrotron, and a possible contribution from inflationary gravitational waves (as parametrized by the tensor-to-scalar ratio r) using priors on the frequency spectral behaviors of dust and synchrotron emission from previous analyses of WMAP and Planck data in other regions of the sky. This analysis yields an upper limit r_{0.05}<0.09 at 95% confidence, which is robust to variations explored in analysis and priors. Combining these B-mode results with the (more model-dependent) constraints from Planck analysis of CMB temperature plus baryon acoustic oscillations and other data yields a combined limit r_{0.05}<0.07 at 95% confidence. These are the strongest constraints to date on inflationary gravitational waves.

Cyclophilin A in Ruptured Intracranial Aneurysm: A Prognostic Biomarker

Cyclophilin A (CyPA), an oxidative stress-induced factor, was found to play an important role in the aneurysm formation. Our working hypothesis was that the plasma level of CyPA in ruptured intracranial aneurysm could predict the neurological outcome. From 2011 to 2013, a total of 36 patients with ruptured saccular intracranial aneurysm were recruited in our study. Before coil embolization, we draw blood samples at the orifice of a culprit aneurysm and in the remote peripheral vein for measurements of the CyPA levels. We utilized the modified Rankin scale 30 days after aneurysm rupture as the outcome measure. Generalized linear models were used to estimate the adjusted odds ratios of the poor neurological outcome given the presence of high plasma level of CyPA. The aneurysmal and venous CyPA levels were significantly associated with the initial clinical severity (P = 0.004 and 0.03, respectively) and 30-day outcome (P = 0.01 and 0.02, respectively). The aneurysmal CyPA levels modestly correlated with age and high Fisher grade (ρ = 0.39 and 0.41; P = 0.02 and 0.01, respectively). The aneurysmal CyPA levels strongly correlated with the venous counterpart (ρ = 0.89; P < 0.001). Patients with high levels of aneurysmal CyPA were 15.66 times (95% CI, 1.48-166.24; P = 0.02) more likely to have worse neurological outcome than those with the low levels after adjustment of the age, gender, and the documented confounding factors. High plasma level of CyPA is a significant prognostic biomarker for poor neurological outcome in patients with ruptured intracranial aneurysm.

Interleukin-6 as a Prognostic Biomarker in Ruptured Intracranial Aneurysms

BACKGROUND

Interleukin-6 (IL-6), a proinflammatory cytokine, was found to surge in the cerebral spinal fluid after aneurysmal subarachnoid hemorrhage (SAH). We hypothesized that the plasma level of IL-6 could be an independent biomarker in predicting clinical outcome of patients with ruptured intracranial aneurysm.

METHODS

We prospectively included 53 consecutive patients treated with platinum coil embolization of the ruptured intracranial aneurysm. Plasma IL-6 levels were measured in the blood samples at the orifices of the aneurysms and from peripheral veins. The outcome measure was the modified Rankin Scale one month after SAH. Multiple logistic regression analyses were used to evaluate the associations between the plasma IL-6 levels and the neurological outcome.

RESULTS

Significant risk factors for the poor outcome were old age, low Glasgow Coma Scale (GCS) on day 0, high Fisher grades, and high aneurysmal and venous IL-6 levels in univariate analyses. Aneurysmal IL-6 levels showed modest to moderate correlations with GCS on day 0, vasospasm grade and Fisher grade. A strong correlation was found between the aneurysmal and the corresponding venous IL-6 levels (ρ = 0.721; P<0.001). In the multiple logistic regression models, the poor 30-day mRS was significantly associated with high aneurysmal IL-6 level (OR, 17.97; 95% CI, 1.51-214.33; P = 0.022) and marginally associated with high venous IL-6 level (OR, 12.71; 95% CI, 0.90-180.35; P = 0.022) after adjusting for dichotomized age, GCS on day 0, and vasospasm and Fisher grades.

CONCLUSIONS

The plasma level of IL-6 is an independent prognostic biomarker that could be used to aid in the identification of patients at high-risk of poor neurological outcome after rupture of the intracranial aneurysm.

Joint analysis of BICEP2/keck array and Planck Data

We report the results of a joint analysis of data from BICEP2/Keck Array and Planck. BICEP2 and Keck Array have observed the same approximately 400  deg^{2} patch of sky centered on RA 0 h, Dec. -57.5°. The combined maps reach a depth of 57 nK deg in Stokes Q and U in a band centered at 150 GHz. Planck has observed the full sky in polarization at seven frequencies from 30 to 353 GHz, but much less deeply in any given region (1.2  μK deg in Q and U at 143 GHz). We detect 150×353 cross-correlation in B modes at high significance. We fit the single- and cross-frequency power spectra at frequencies ≥150  GHz to a lensed-ΛCDM model that includes dust and a possible contribution from inflationary gravitational waves (as parametrized by the tensor-to-scalar ratio r), using a prior on the frequency spectral behavior of polarized dust emission from previous Planck analysis of other regions of the sky. We find strong evidence for dust and no statistically significant evidence for tensor modes. We probe various model variations and extensions, including adding a synchrotron component in combination with lower frequency data, and find that these make little difference to the r constraint. Finally, we present an alternative analysis which is similar to a map-based cleaning of the dust contribution, and show that this gives similar constraints. The final result is expressed as a likelihood curve for r, and yields an upper limit r_{0.05}<0.12 at 95% confidence. Marginalizing over dust and r, lensing B modes are detected at 7.0σ significance.

Decrease in plasma cyclophilin A concentration at 1 month after myocardial infarction predicts better left ventricular performance and synchronicity at 6 months: a pilot study in patients with ST elevation myocardial infarction

BACKGROUND

Cyclophilin A (CyPA) concentration increases in acute coronary syndrome. In an animal model of acute myocardial infarction, administration of angiotensin-converting-enzyme inhibitor was associated with lower left ventricular (LV) CyPA concentration and improved LV performance. This study investigated the relationships between changes in plasma CyPA concentrations and LV remodeling in patients with ST-elevation myocardial infarction (STEMI).

METHODS AND RESULTS

We enrolled 55 patients who underwent percutaneous coronary intervention for acute STEMI. Plasma CyPA, matrix metalloproteinase (MMP), interleukin-6 and high-sensitivity C-reactive protein concentrations were measured at baseline and at one-month follow-up. Echocardiography was performed at baseline and at one-, three-, and six-month follow-up. Patients with a decrease in baseline CyPA concentration at one-month follow-up (n = 28) had a significant increase in LV ejection fraction (LVEF) (from 60.2 ± 11.5% to 64.6 ± 9.9%, p < 0. 001) and preserved LV synchrony at six months. Patients without a decrease in CyPA concentration at one month (n = 27) did not show improvement in LVEF and had a significantly increased systolic dyssynchrony index (SDI) (from 1.170 ± 0.510% to 1.637 ± 1.299%, p = 0.042) at six months. Multiple linear regression analysis showed a significant association between one-month CyPA concentration and six-month LVEF. The one-month MMP-2 concentration was positively correlated with one-month CyPA concentration and LV SDI. Conclusions : Decreased CyPA concentration at one-month follow-up after STEMI was associated with better LVEF and SDI at six months. Changes in CyPA, therefore, may be a prognosticator of patient outcome.

Intracranial venous hemodynamics and rupture of cerebral aneurysm

Many uncertain and inconsistent etiologies of cerebral aneurysmal rupture including a wide spectrum of factors have been reported. Our recent observation discloses the potential new factor of cerebral aneurysm rupture with cerebral venous pressure gradient. We retrospectively reviewed 52 cases treated with coil embolization with or without cerebral aneurysmal rupture. Seventeen males and 30 females were recruited in this study. Quantitative color-coded cerebral angiography was performed during coil therapeutic procedures to measure cerebral venous circulation. Ruptured cases had shorter and symmetrical cerebral venous circulation time (P <0.05). In addition, an asymmetrical venous outflow pattern was critical for aneurysmal rupture. Non-ruptured cases tended to have slower and asymmetrical cerebral venous circulation compared with rupture cases. Symmetrical and shorter cerebral venous circulation in the dysplasia venous outlet may be a potential new factor for cerebral aneurysm rupture.

Detection of B-mode polarization at degree angular scales by BICEP2

We report results from the BICEP2 experiment, a cosmic microwave background (CMB) polarimeter specifically designed to search for the signal of inflationary gravitational waves in the B-mode power spectrum around ℓ∼80. The telescope comprised a 26 cm aperture all-cold refracting optical system equipped with a focal plane of 512 antenna coupled transition edge sensor 150 GHz bolometers each with temperature sensitivity of ≈300  μK(CMB)√s. BICEP2 observed from the South Pole for three seasons from 2010 to 2012. A low-foreground region of sky with an effective area of 380 square deg was observed to a depth of 87 nK deg in Stokes Q and U. In this paper we describe the observations, data reduction, maps, simulations, and results. We find an excess of B-mode power over the base lensed-ΛCDM expectation in the range 30 < ℓ < 150, inconsistent with the null hypothesis at a significance of >5σ. Through jackknife tests and simulations based on detailed calibration measurements we show that systematic contamination is much smaller than the observed excess. Cross correlating against WMAP 23 GHz maps we find that Galactic synchrotron makes a negligible contribution to the observed signal. We also examine a number of available models of polarized dust emission and find that at their default parameter values they predict power ∼(5-10)× smaller than the observed excess signal (with no significant cross-correlation with our maps). However, these models are not sufficiently constrained by external public data to exclude the possibility of dust emission bright enough to explain the entire excess signal. Cross correlating BICEP2 against 100 GHz maps from the BICEP1 experiment, the excess signal is confirmed with 3σ significance and its spectral index is found to be consistent with that of the CMB, disfavoring dust at 1.7σ. The observed B-mode power spectrum is well fit by a lensed-ΛCDM+tensor theoretical model with tensor-to-scalar ratio r = 0.20_(-0.05)(+0.07), with r = 0 disfavored at 7.0σ. Accounting for the contribution of foreground, dust will shift this value downward by an amount which will be better constrained with upcoming data sets.

Presence of cytomegalovirus DNA in leucocytes is associated with increased oxidative stress and subclinical atherosclerosis in healthy adults

OBJECTIVE

Investigate the latent cytomegalovirus (CMV) infection as a biomarker of oxidative stress and atherosclerosis.

METHODS

Latent CMV infection was diagnosed in healthy individuals with PCR-evidence of CMV DNA in peripheral leucocytes. Oxidative stress and atherosclerosis were measured by mitochondrial DNA oxidative damage index (mtDNA(ΔCT)) and intima media thickness (IMT).

RESULTS

The CMV DNA positive subjects had a higher mean mtDNA(ΔCT) and greater IMT than subjects in the control group.

CONCLUSIONS

Presence of CMV DNA in leucocytes, as a marker of latent CMV infection, was associated with increased levels of oxidative stress and subclinical atherosclerosis in healthy adults.

Cyclophilin-A: a novel biomarker for untreated male essential hypertension

Vascular cytokines, total nitrite, and cyclophilin-A (CyP-A) may be related to the pathogenesis of untreated hypertension. Forty males with normotensive and untreated essential hypertension were recruited in this cytokines survey. Body mass index (BMI), hyperlipidemia, and plasma CyP-A were increased in the hypertensive group (p < 0.05). However, only BMI (p = 0.022) and plasma CyP-A (p = 0.020) were found to be significant contributors to hypertension by multiple regression analysis. CyP-A was also positively correlated with systolic blood pressure (p = 0.029) and diastolic blood pressure (p = 0.047). These findings indicated that plasma CyP-A is a critical molecular biomarker in the early pathogenesis of essential hypertension.

Endogenous granulocyte colony-stimulating factor: a biomarker in acute ischemic stroke

Granulocyte colony-stimulating factor (G-CSF) may protect ischemic brain injury either in animal or human. No studies have reported that endogenous G-CSF (enG-CSF) level is related to the severity of ischemic stroke. This study was designed to assess the severity of ischemic patients correlated with the alteration of enG-CSF on the 1st day after an ischemic event. Patient's plasma enG-CSF and scoring of National Institute of Health Stroke Scale were measured on the 1st day after ischemic stroke. The acute ischemic stroke could significantly induce enG-GCF secretion as compared with healthy control group (16.77 vs. 22.86 μg/L, p = 0.001). Elevated enG-CSF concentration was positively correlated with the severity of stroke patients on day 1 after the event (p = 0.006; Spearman correlation coefficient = 0.268). The enG-CSF is a good biomarker for prediction of severity of acute ischemic stroke.

Gluten sensitivity: associated sporadic cerebellar ataxia in Taiwan

PURPOSE

Gluten sensitivity (GS) is related to the pathogenesis of sporadic or hereditary ataxia.

METHODS

Total of 194 healthy controls and patients with either hereditary ataxia (n=207) or sporadic ataxia (n=361) were tested for the circulating gluten-related autoantibodies which serve as biomarkers to interpret the existence of GS.

RESULTS

The incidences of GS in each population were 1% in normal subjects, 2% in hereditary ataxia patients and 9% in sporadic ataxia patients. High serum level of anti-gliadin IgG/IgA and t-transglutaminase IgA were disclosed at the sporadic ataxia patients compared with normal subjects. However, the anti-gliadin IgG is more specific to the disease of sporadic ataxia.

CONCLUSION

Relatively higher incidence of GS was found in the population of sporadic ataxia patients but not in either normal subjects or hereditary ataxia patients in Taiwan. Anti-gliadin IgG still is a very powerful indicator to implicate the immune-related sporadic ataxia and we conclude that GS-related sporadic ataxia exists in Taiwan with linkage to autoimmune events.

The MTHFR 677 C/T polymorphism influences plasma levels of adhesion molecules and nitric oxide

BACKGROUND

Hyperhomocysteinemia is an independent risk factor for cardiovascular events. The T allele of 677 C/T polymorphism at the methylenetetrahydrofolate reductase (MTHFR) gene has been reported to induce mild hyperhomocysteinemia. In the present study, we investigated the relationship between this polymorphism and adhesion molecules and total nitric oxide (NOx).

METHODS

The adhesion molecules tested in the present study were soluble E-selectin (sE-selectin), vascular adhesion molecule (sVCAM), and intercellular adhesion molecule (sICAM). A total of 297 subjects had data on these atherosclerotic biomarkers and the MTHFR genotypes. The genetic effect was estimated in the multivariate regression models with adjustment of covariates. Homocysteine, folate, vitamin B6 and vitamin B12 levels were measured in 181 subjects for the test of association between the biomarkers and homocysteine levels.

RESULTS

The genotype distribution was in Hardy-Weinberg equilibrium. The sVCAM levels increased with the number of the T allele, while the NOx levels decreased with the number of the T allele. We found that the T allele was significantly associated with high sVCAM levels (p=0.002) and low NOx levels (p=0.011) in the regression models. The MTHFR genotypes were associated with homocysteine levels (p=0.031). Mild hyperhomocysteinemia (>12 micromol/L) was significantly associated with sVCAM levels (p=0.036). The NOx levels were lower in the hyperhomocysteinemia group than in the normal homocysteine group, but the difference was not significant. The genotypes were not significantly associated with either sE-selectin or sICAM.

CONCLUSIONS

The detrimental T allele exerted an additive effect to increase sVCAM and decrease NOx concentrations, which may contribute to atherosclerosis.

B-group vitamins, MTHFR C677T polymorphism and carotid intima-media thickness in clinically healthy subjects

OBJECTIVE

Plasma B-group vitamins and age may affect the carotid intima-media thickness (IMT) in subjects with different 677TT genotype of the methylenetetrahydrofolate reductase (MTHFR) gene.

DESIGN

A hospital-based cross-study.

SETTING

Genomic and Vascular Center, Changhua Christian Hospital, Changhua, Taiwan.

SUBJECTS

Five hundred and forty-one clinically healthy subjects.

INTERVENTION

Fasting plasma, homocysteine (Hcy), vitamin B(6), vitamin B(12), folate and B-mode carotid ultrasound.

RESULTS

MTHFR genotype, plasma concentrations of folate, vitamin B(6) and vitamin B(12) and age were significantly correlated to the plasma Hcy concentration. MTHFR 677TT carriers had higher concentrations of Hcy than did subjects with the CC and CT genotypes. Age, sex, body mass index and plasma Hcy were independent contributors to increase carotid IMT. However, with stratification by mean value of age and B-group vitamins concentrations, we found that at advanced age, lower plasma folate and vitamin B(12) were three risk factors involved in the enhancing effect of the MTHFR 677TT genotype on the increase of plasma Hcy and carotid IMT.

CONCLUSION

MTHFR 677TT-related carotid atherosclerosis was only identified in healthy elderly subjects with lower level of plasma folate and vitamin B(12).

SPONSORSHIP

Changhua Christian Hospital.

G-protein coupled receptors: SAR analyses of neurotransmitters and antagonists

BACKGROUND

From the deductive point of view, neurotransmitter receptors can be divided into categories such as cholinergic (muscarinic, nicotinic), adrenergic (alpha- and beta-), dopaminergic, serotoninergic (5-HT1 approximately 5-HT5), and histaminergic (H1 and H2). Selective agonists and antagonists of each receptor subtype can have specific useful therapeutic applications. For understanding the molecular mechanisms of action, an inductive method of analysis is useful.

OBJECTIVE

The aim of the present study is to examine the structure-activity relationships of agents acting on G-protein coupled receptors.

METHOD

Representative sets of G-PCR agonists and antagonists were identified from the literature and Medline [P.M. Walsh (2003) Physicians' Desk Reference; M.J. O'Neil (2001) The Merck Index]. The molecular weight (MW), calculated logarithm of octanol/water partition coefficient (C log P) and molar refraction (CMR), dipole moment (DM), E(lumo) (the energy of the lowest unoccupied molecular orbital, a measure of the electron affinity of a molecule and its reactivity as an electrophile), E(homo) (the energy of the highest occupied molecular orbital, related to the ionization potential of a molecule, and its reactivity as a nucleophile), and the total number of hydrogen bonds (H(b)) (donors and receptors), were chosen as molecular descriptors for SAR analyses.

RESULTS

The data suggest that not only do neurotransmitters share common structural features but their receptors belong to the same ensemble of G-protein coupled receptor with seven to eight transmembrane domains with their resultant dipoles in an antiparallel configuration. Moreover, the analysis indicates that the receptor exists in a dynamic equilibrium between the closed state and the open state. The energy needed to open the closed state is provided by the hydrolysis of GTP. A composite 3-D parameter frame setting of all the neurotransmitter agonists and antagonists are presented using MW, Hb and mu as independent variables.

CONCLUSION

It appears that all neurotransmitters examined in this study operate by a similar mechanism with the G-protein coupled receptors.

Oxidative stress-related alteration of the copy number of mitochondrial DNA in human leukocytes

The role of oxidative stress in the regulation of the copy number of mitochondrial DNA (mtDNA) in human leukocytes is unclear. In this study, we investigated the redox factors in plasma that may contribute to the alteration of mtDNA copy number in human leukocytes. A total of 156 healthy subjects of 25-80 years of age who exhibited no significant difference in the distribution of subpopulations of leukocytes in blood were recruited. Small-molecular-weight antioxidants and thiobarbituric acid reactive substances (TBARS) in plasma and 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 4,977bp deletion of mtDNA in leukocytes were determined. The mtDNA copy number in leukocytes was determined by real-time PCR. The results showed that the copy number of mtDNA in leukocytes was changed with age in a biphasic manner that fits in a positively quadratic regression model (P = 0.001). Retinol (P = 0.005), non-protein thiols (P = 0.001) and ferritin (P = 0.004) in plasma and total glutathione in erythrocytes (P = 0.046) were the significant redox factors that correlated with the mtDNA copy number in leukocytes in a positive manner. By contrast, alpha-tocopherol levels in plasma (P = 0.001) and erythrocytes (P = 0.033) were negatively correlated with the mtDNA copy number in leukocytes. Three oxidative indices including the incidence of 4,977 bp deletion of mtDNA (P = 0.016) and 8-OHdG content in leukocytes (P = 0.003) and TBARS in plasma (P = 0.001) were all positively correlated with the copy number of mtDNA in leukocytes. Taken these findings together, we suggest that the copy number of mtDNA in leukocytes is affected by oxidative stress in blood circulation elicited by the alteration of plasma antioxidants/prooxidants and oxidative damage to DNA.

Structure-activity relationship: analyses of p-glycoprotein substrates and inhibitors

OBJECTIVE

A large number of structurally and functionally diverse compounds act as substrates or modulators of p-glycoprotein (p-gp). Some of them possess multiple drug resistance (MDR)-reversing activity, but only a small number of them have entered clinical study. In order to uncover the factors which exert a significant impact on the interaction between substrates/modulators and p-gp, we have performed structure-activity relationship (SAR) analyses, including molecular modelling, two-dimensional (2D) and three-dimensional (3D) parameter-frame-setting analysis, quantitative structure activity relationship (QSAR) analysis among substrates/modulators, as well as clinically promising MDR-reversing agents.

METHODS

The physicochemical parameters C log P, CMR and all regression equations were derived by using C log P version 4.0 and the latest CQSAR software, respectively. Molecular modelling and all other parameter calculations were performed by using HyperChem version 5.0 program, after geometry optimization and energy minimization using the AM1 semiempirical method.

RESULTS

SAR analyses indicate that MDR reversal activity is correlated with the lipophilicity (C log P), molecular weight (log Mw), longest chain (Nlc) of the molecule and the energy of the highest occupied orbital (Ehomo). In addition, the presence of a basic tertiary nitrogen atom in the structure is also an important contributor to p-gp inhibitory activity. Some separation in space is achieved for different subsets of p-gp substrates and inhibitors using Nlc, C log P and Ehomo as three independent parameters in the 3D-parameter-frame setting.

CONCLUSION

A highly effective p-gp modulator candidate should possess a log P value of 2.92 or higher, 18-atom-long or longer molecular axis, and a high Ehomo value, as well as at least one tertiary basic nitrogen atom. The results obtained may be useful in explaining drug-p-gp interactions for different compounds, including drug interactions and the development of new MDR chemosensitizers.

In vitro study of ultrasound based real-time tracking for renal stones in shock wave lithotripsy: Part II--a simulated animal experiment

PURPOSE

We have previously developed and reported an ultrasound based real-time tracking system for renal stones. In the current study we continued to verify the reliability of this tracking system by a simulated animal test.

MATERIALS AND METHODS

We used 13 prerecorded ultrasound stone trajectories to test the system. The real-time tracking system was implemented on the Litemed 9200 electrohydraulic lithotriptor (LiteMed Co., Taipei, Taiwan). An artificial stone and tap water were sealed in a balloon. The balloon was inserted into the pelvis of a pig kidney. While the kidney was affixed to and moved by a simulator, it was immersed in a specifically designed simulated animal model tank containing tap water. The stone was localized by ultrasound. The kidney was moved by the simulator according to a prerecorded stone trajectory. A total of 3,000 shock waves were delivered to the stone. For each recorded stone trajectory experiments were done under nontracking and tracking conditions. We performed tests of the fragment-to-weight ratio, which denotes the performance of a shock wave lithotriptor when fragmenting a stone.

RESULTS

The mean fragment-to-weight ratio was 55.3% +/- 25.9% in the nontracking and 100% +/- 0% in the tracking group. The difference in these 2 groups was statistically significant (paired t test p <0.01).

CONCLUSIONS

The ultrasound based real-time tracking system proved to improve the performance of a shock wave lithotriptor significantly when fragmenting stones in a simulated animal test. We believe that the tracking system would greatly reduce the number of shocks and time needed for treating renal stones.

Alterations of plasma antioxidants and mitochondrial DNA mutation in hair follicles of smokers

The effects of long-term smoking on mitochondrial DNA (mtDNA) deletions in hair follicles were investigated in subjects with different antioxidant capacity. Twenty-two male smokers with a smoking index of greater than 5 pack-years and without any known systemic diseases were recruited for this study. Forty healthy nonsmoking males were included as controls. We found that the concentrations of ascorbate and alpha-tocopherol and the activities of glutathione S-transferase (GST) and glutathione peroxidase in blood plasma were significantly decreased in smokers. The levels of glutathione and protein thiols in whole blood and the incidence of a 4,977 bp deletion of mtDNA (dmtDNA) in hair follicles were significantly increased in smokers. A significantly higher incidence of the 4,977 bp dmtDNA was found in smokers with plasma GST activity less than 5.66 U/l (OR = 7.2, P = 0.020). Using multiple covariate ANOVA and logistic regression, we found that age and low plasma GST activity were the only two risk factors for the 4,977 bp dmtDNA. These results suggest that smoking depletes antioxidants and causes mtDNA deletions and that plasma GST may play an important role in the preservation of the mitochondrial genome in tissue cells of smokers.

De novo regeneration of Scrophularia yoshimurae Yamazaki (Scrophulariaceae) and quantitative analysis of harpagoside, an iridoid glucoside, formed in aerial and underground parts of in vitro propagated and wild plants by HPLC

A protocol for de novo regeneration and rapid micropropagation of Scrophularia yoshimurae (Scrophulariaceae) has been developed. Multiple shoot development was achieved by culturing the shoot-tip, leaf-base, stem-node and stem-internode explants on Murashige and Skoog (MS) medium supplemented with 4.44 microM N6-benzyladenine (BA) and 1.07 microM alpha-naphthaleneacetic acid (NAA). Stem-node and shoot-tip explants showed the highest response (100%) followed by stem-internode (74.4%) and leaf-base (7.7%) explants. The shoots were multiplied by subculturing on the same medium used for shoot induction. Shoots were rooted on growth regulator-free MS basal medium and the plantlets were transplanted to soil and acclimatized in the growth chamber. The content of harpagoside, a quantitatively predominant iridoid glycoside, in different plant material was determined by high performance liquid chromatography (HPLC). The analysis revealed that the content of harpagoside in the aerial and underground parts of S. yoshimurae was significantly higher than the marketed crude drug (underground parts of Scrophularia ningpoensis).

In vitro study of ultrasound based real-time tracking of renal stones for shock wave lithotripsy: part 1

PURPOSE

We developed a real-time tracking system for renal stones that decreases the number of shock waves and treatment time of shock wave lithotripsy.

MATERIALS AND METHODS

Ultrasound images were analyzed to identify the renal stones. A computer software module for ultrasound image processing was developed to monitor stone location instantaneously. Another computer software module controlled generator movement in real time for tracking the stone. We used 13 ultrasound stone trajectories recorded from patients to test the system in vitro. Two tests were established to verify tracking system reliability. One test focused on improvement in the coincidence ratio, which denotes the matching extent of the stone within the effective focal area. The other test focused on improvement in the efficiency ratio, that is a decrease in the number of shocks for stone fragmentation. For each recorded stone trajectory 2 experiments were done under tracking and nontracking conditions.

RESULTS

The average coincidence and efficiency ratios plus or minus standard deviation were 79.6% +/- 9.8% and 45.0% +/- 12.7% without tracking, and 97.0% +/- 3.0% and 85.5 +/- 6.8% with tracking, respectively. All tests were statistically significant (paired t test p <0.01).

CONCLUSIONS

An ultrasound based real-time tracking system proved to be significantly helpful for in vitro lithotripsy. It appears that the tracking system may greatly decrease the number of shocks and treatment time for renal stones.

A conserved sequence block in the murine and human T cell receptor Jalpha loci interacts with developmentally regulated nucleoprotein complexes in vitro and associates with GATA-3 and octamer-binding factors in vivo

A highly conserved sequence block (CSB) located in the mouse and human T cell receptor (TCR) Jalpha loci is recognized by tissue-specific factors and up-regulates TCR alpha enhancer activity. In this study, the properties of CSB-interacting factors were further explored to decipher the function of this cis-acting element. Thymocytes corresponding to different developmental stages were found capable of forming differential CSB-nucleoprotein complexes. Pronounced changes in the CSB-complex-forming activity were observed during the transition from double-negative to double-positive thymocytes. Furthermore, we showed that transcription factors Oct-1, Oct-2 and GATA-3 interacted with CSB both in vitro, as evidenced by electrophoretic mobility shift assays, and in vivo, as demonstrated by chromatin immunoprecipitation assays in mouse thymus. Importantly, we also demonstrated that GATA-3 associated in vivo with TCR alpha enhancer, the activity of which is known to be required in regulating chromatin accessibility to the V(D)J recombinase. Thus, CSB may temporally regulate local chromatin structure and help to spread TCR alpha enhancer activity over the entire 70-kb Jalpha locus by forming developmentally regulated CSB-nucleoprotein complexes and by interacting with other cis-regulatory element-nucleoprotein complexes present within the TCR alpha / delta locus.

Discrete species of activated oxygen yield different cytochrome P450 heme adducts from aldehydes

Aldehydes are known to inactivate cytochrome P450 in the reconstituted enzyme system containing NADPH and NADPH-cytochrome P450 reductase under aerobic conditions in a mechanism-based reaction involving heme adduct formation [Raner, G. M., Chiang, E. W. , Vaz, A. D. N., and Coon, M. J. (1997) Biochemistry 36, 4895-4902]. In the study presented here, artificial oxidants were used to examine the mechanism of aldehyde activation by purified P450 2B4 in the absence of the usual O(2)-reducing system, and the adducts that were formed were isolated and characterized. With hydrogen peroxide as the oxidant, 3-phenylpropionaldehyde gives an adduct with a mass corresponding to that of native heme modified by a phenylethyl group, presumably arising from the reaction of a peroxy-iron species with the aldehyde to give a peroxyhemiacetal, which upon deformylation yields the alkyl radical. NMR analysis indicated that the substitution is specifically at the gamma-meso position. In contrast, with m-chloroperbenzoic acid as the oxidant, an adduct is formed from 3-phenylpropionaldehyde with a mass that is consistent with the addition of a phenylpropionyl group, apparently arising by hydrogen abstraction from the aldehyde to give the carbonyl carbon radical. m-Chloroperbenzoic acid by itself forms a heme adduct with a mass corresponding to the addition of a chlorobenzoyloxy group apparently derived from homolytic oxygen-oxygen bond cleavage. These and other results with nonanal and 2-trans-nonenal support the concept that this versatile enzyme utilizes discrete oxidizing species in heme adduct formation from aldehydes.

Epidural catheter placement in the rabbit--a novel approach

BACKGROUND

Using a pediatric epidural set and through caudal approach, we studied a relatively non-invasive technique for epidural percutaneous cannulation in rabbit for chronic laboratory investigations.

METHODS

Ten rabbits weighing over 3 kg were chosen and anesthetized with intravenous pentothal. A #19 pediatric Touhy needle and 23-gauge catheter were used for cannulation. Via the caudal approach, the epidural space could be located either by a "give" or with a technique of loss of resistance. Under fluoroscopy the catheter was tested with the injection of contrast medium for the confirmation of the proper position. The catheter was then tunneled under the skin and secured. The rabbits were kept in standard care for 4 weeks and then sacrificed by intraperitoneal pentothal overdose. A pathologist blinded to the study carefully examined the whole spine by laminectomy from cervical to coccyx and the findings were recorded.

RESULTS

With the injection of contrast medium, the final position of the catheter was validated by fluoroscopy in all rabbits. Two rabbits sustained immediate complications from the contrast medium and/or technique, of which one died shortly after the contrast medium injection and the other had weakness of the hind legs for a week. At sacrifice, all the catheters were found in good position. Two had hematoma associated with signs of trauma. One developed subcutaneous abscess. One had stitch infection of skin.

CONCLUSIONS

Percutaneous cannulation of epidural catheter is possible in the rabbit. Complications could be ameliorated by prudent approach in a skillful hand. It can be a reasonable model for the study of centrally administered medicines and their neurotoxicity.

Cytochrome P450 2E1 mRNA in the rat prostate: detection and quantitation by competitive reverse transcription and polymerase chain reaction

Cytochrome P450 2E1 plays a pivotal role in the metabolic activation of a wide variety of low molecular weight environmental toxicants and procarcinogens. In the present study, expression of the P450 2E1 gene in the rat prostate gland was quantitated by competitive reverse transcription and the polymerase chain reaction. To assess accurately the induction level of P450 2E1 mRNA in the prostate after pyridine treatment of rats, a recombinant standard RNA was generated that is homologous to the sequence of P450 2E1 mRNA except for an internal deletion of 100 bases. The data indicate that P450 2E1 mRNA is present in the prostate of untreated animals and is induced about four-fold by treatment with pyridine. The results suggest that exposure to certain environmental chemicals and procarcinogens may increase P450 2E1 levels in the prostate gland and thus could enhance formation of reactive, carcinogenic metabolites.

Calcium binding by human and rabbit serum paraoxonases. Structural stability and enzymatic activity

Equilibrium dialysis and Scatchard plots were used to establish that human and rabbit paraoxonases both have two calcium binding sites. Independent-site and stepwise constant analyses were used to calculate a higher affinity site (Kd1) of 3.6 +/- 0.9 x 10(-7) M for human A paraoxonase, and 1.4 +/- 0.5 x 10(-8) M for rabbit paraoxonase, and a lower affinity site (Kd2) of 6.6 +/- 1.2 x 10(-6) M for human A paraoxonase, and 5.3 +/- 0.94 x 10(-6) M for rabbit paraoxonase. In both species, the higher affinity sites were found to be essential to maintain hydrolytic activity; complete removal of calcium led to irreversible inactivation. The lower affinity sites were required for catalytic activity, and their binding of calcium was reversible. Experimentally estimated values of Kd2 based on the concentration of calcium required to obtain half the maximum enzymatic activity were 3 microM for human A and B paraoxonases, and also in the order of 3 microM for rabbit paraoxonase, using three different substrates. Calcium was the only metal found that protects against denaturation and also confers hydrolytic activity with these two mammalian paraoxonases.

The detection of cytochrome P450 2E1 and its catalytic activity in rat testis

Cytochrome P450 2E1 participates in the bioactivation of a wide variety of environmental and occupational pollutants. Such reactions may lead to the production of active carcinogenic metabolites. The presence of P450 2E1 in the testis and prostate has not yet been reported. In the present study, cytochrome P450 2E1 mRNA has been identified in the rat prostate and testis by reverse transcription PCR, southern blotting, and DNA sequencing. P450 2E1 protein from rat testis could be detected with immunoblot analysis, but was not detected in the prostate. The hydroxylation of p-nitrophenol, known to be mediated by P450 2E1, was demonstrated by HPLC measurement of product formation in microsomal fractions from the rat testis, but again not from prostate. Exposure of rats to pyridine resulted in a 2.9-fold increase of p-nitrophenol hydroxylation by testicular microsomes. Diethyldithiocarbamate, a selective mechanism-based inhibitor of P450 2E1, or a P450 2E1 monoclonal antibody, caused marked inhibition of testicular microsomal p-nitrophenol hydroxylase activity. These results indicate that cytochrome P450 2E1 is present in the rat testis, and that it is elevated by the treatment of the animals with pyridine. Thus, the presence and inducibility of cytochrome P450 2E1 in the testis may be of significance in the bioactivation of environmental chemicals to genotoxic metabolites.

A conserved sequence block in murine and human T cell receptor (TCR) Jalpha region is a composite element that enhances TCR alpha enhancer activity and binds multiple nuclear factors

A conserved sequence block (CSB) located in a noncoding region of the mouse and human TCR alpha/delta loci, showing six differences over 125 nucleotide positions (95% similar), was subjected to detailed analyses in this study. Transient transfection results showed that the CSB-containing element in conjunction with the TCR alpha enhancer up-regulated the alpha enhancer activity, whereas no enhancer activity was detected when CSB alone was assayed. In vitro occupancy analyses of CSB by nuclear factors reveal the existence of an unexpectedly intricate network of CSB-protein and protein-protein interactions. Lymphoid-specific as well as T-lineage-specific nuclear factors are involved to differentially form CSB-bound complexes in extracts of various tissues and cell lines. Liver was shown to contain factor(s) sequestering thymic CSB-binding factors. Furthermore, the putative binding sites for transcription factors known to be important for lymphoid-lineage development are present in CSB and are targeted by nuclear factors. On the basis of these results, we propose that the CSB element may play a role in shaping the chromatin structure by which the accessibility of TCR alpha/delta loci to the recombinase complex and/or to the transcriptional apparatus can be controlled.

Metabolic activation of trans-4-hydroxy-2-nonenal, a toxic product of membrane lipid peroxidation and inhibitor of P450 cytochromes

Lipid peroxidation in biological membranes is known to yield reactive aldehydes, of which trans-4-hydroxy-2-nonenal (HNE) is particularly cytotoxic. This laboratory previously reported that purified liver microsomal P450 cytochromes are directly inactivated to varying extents by HNE. We have now found a mechanism-based reaction in which P450s are inactivated by HNE in the presence of molecular oxygen, NADPH, and NADPH-cytochrome P450 reductase. The sensitivity of the various isozymes in the two pathways is different as follows: P450 2B4 and the orthologous 2B1 are inactivated to the greatest extent and 2C3, 1A2, 2E1, and 1A1 to a somewhat lesser extent by the pathway in which HNE undergoes metabolic activation. In contrast, 2B4 and 2B1 are insensitive to direct inactivation, and the reductase is unaffected by HNE by either route. Recent studies on the catalytic activities of the T302A mutant of P450 2B4 have shown that the rate of oxidation of a variety of xenobiotic aldehydes to carboxylic acids is decreased, but the rates of aldehyde deformylation and mechanism-based inactivation of the cytochrome are stimulated over those of the wild-type enzyme (Raner, G. M., Vaz, A. D. N., and Coon, M. J. (1997) Biochemistry 36, 4895-4902). Inactivation by those aldehydes apparently occurs by homolytic cleavage of a peroxyhemiacetal intermediate to yield formate and an alkyl radical that reacts with the heme. In sharp contrast, the rate of mechanism-based inactivation by HNE is decreased with the T302A mutant relative to that of the wild-type P450 2B4, and mass spectral analysis of the heme adduct formed shows that deformylation does not occur. We therefore propose that the metabolic activation of HNE involves formation of an acyl carbon radical that leads to the carboxylic acid or alternatively reacts with the heme.

A highly conserved apoptotic suppressor gene is located near the chicken T-cell receptor alpha chain constant region

A cosmid clone containing the chicken T-cell receptor alpha chain constant region (TCRAC) was sequenced. The cosmid contains the TCRAC gene, six putative joining gene segments (TCRAJ), and surprisingly, a chicken homologue for the human apoptotic suppressor gene, defender against cell death (DAD1). The DAD1 gene is 6.3 kilobases downstream of the TCRAC gene and has an inverted transcription orientation with respect to the TCRAC gene. The cDNA for the chicken DAD1 gene is 597 base pairs in length and encodes a highly conserved hydrophobic protein. The proximal location of DAD1 to the TCRAC locus has also been confirmed in both humans and mouse. The location of the DAD1 gene suggests that DAD1 may play an important role in T-cell related apoptotic activities.

Comparison of purified human and rabbit serum paraoxonases

Rabbit serum paraoxonase (PON) activity was reported to be nearly 20 times greater than that found for humans and all other mammalian species tested, to date. However, 85% of the amino acid residues are identical in human and rabbit PONs, and the two purified PONs show similar substrate specificity patterns. Both are stimulated by phospholipids and have two asparagine-linked sugar chains. Both also have one intramolecular disulfide bond and one free sulfhydryl residue per molecule. Both require Ca2+ for stability and for catalytic activity. Zn2+ and Cd2+ also stabilize both PONs and prevent irreversible denaturation, but neither metal confers catalytic activity. Maximum specific activities for both esterases were approximately 2,000 units of arylesterase activity/mg protein. In contrast, rabbit PON is more stable than human PON to heat inactivation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis treatment. Chelex 100 strips Ca2+ from human PON more easily, and EDTA is less inhibitory with rabbit PON. We conclude that human and rabbit PONs have very similar active centers, but the latter binds Ca2+ more tightly, is a more stable enzyme, and is maintained at 3- to 4-fold higher steady-state concentrations in serum than its human counterpart. PON activity depends on adequate Ca2+ being available; therefore, apparently much higher levels of PON activity in rabbits can be explained by the reduced Ca2+ concentrations present in the early assay methods.