Publications

There is a strong association between metabolic syndrome (MS) and increased risk of end-organ damage, cardiovascular disease, stroke, and cardiovascular mortality. Moreover, non-dipping (<10% decline in the asleep relative to the awake blood pressure [BP] mean) and elevated ambulatory pulse pressure (PP), among other factors related to the circadian BP pattern, have also been associated with increased cardiovascular morbidity and mortality. This cross-sectional study investigated the circadian BP pattern in 2,045 non-diabetic untreated patients with uncomplicated essential hypertension (941 men/1,099 women), 48.7+/-11.9 yrs of age, classified by the presence or absence of MS. BP was measured by ambulatory monitoring for 48 consecutive hours to substantiate reproducibility of the dipping pattern. Physical activity was simultaneously monitored every min by wrist actigraphy to accurately calculate mean BP when awake and asleep for each subject. MS was present in 40.7% of the patients. Patients with MS were characterized by a significantly higher 24 h mean of systolic BP and a lower diastolic BP compared to patients without MS. Accordingly, ambulatory PP was significantly elevated the entire 24 h in MS patients. The prevalence of an altered non-dipper BP profile was significantly higher in MS patients (48.4 vs. 36.1% in patients without MS, p < 0.001). MS patients were characterized, among other risk factors, by significantly higher uric acid, fibrinogen, leukocyte count, hemoglobin and globular sedimentation velocity, plus lower estimated glomerular filtration rate. Apart from corroborating the significant increased prevalence of a blunted nocturnal BP decline in MS, this study documents ambulatory PP is higher in MS, without differences between groups in mean arterial pressure. This elevated PP might reflect increased arterial stiffness in MS. MS patients were also characterized by elevated values of relevant markers of cardiovascular risk, including fibrinogen and globular sedimentation velocity. These collective findings indicate that MS should be included among the clinical situations in which ambulatory BP monitoring is recommended.

Changes in 24-h synchronized (circadian) characteristics of blood pressure (BP) and heart rate (HP) are quantified in two consecutive pregnancies of a clinically healthy woman. BP and HR were automatically monitored, with few interruptions, at 1-h intervals, and for a total of 76 days of monitoring in each pregnancy. Circadian parameters of BP and HR were computed for each single day of measurements by the least-squares fit of a 24-h cosine curve. Regression analysis of parameters thus obtained revealed patterns of variation of circadian rhythm-adjusted means and amplitudes with gestational age. This longitudinal study confirms and extends to ambulatory everyday-life conditions the predictable pregnancy-associated variability in BP and HR, and also allows the establishment of prediction and confidence limits for cardiovascular parameters in a healthy pregnancy.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Abstract Copper speciation in the presence of fulvic acids (FAs) was studied in chemically defined seawater by square wave anodic stripping voltammetry (SQWASV). A simple complexation model assuming a single type of ligand and a 1:1 reaction stoichiometry successfully explained the measured data. A conditional stability constant of 5.80 ± 0.07 and a complexing capacity of 610 ± 80 μmol Cu/g FAs were obtained. This conditional stability constant would correspond to 7.23 on a free copper ion basis. The complexation kinetics was easily followed by anodic stripping voltammetry (ASV) measurements, and complexation equilibria were not reached until approximately 12 h. Coupled to speciation studies, the toxicity of copper in the presence of FAs was studied with the sea urchin Paracentrotus lividus embryogenesis bioassay. A clear protective effect of FAs was observed on Cu toxicity, and this effect could be accurately explained by SQWASV Cu speciation measurements. Additional experiments in the presence of high Cu and FA concentrations were performed, and no extra toxicity of Cu–FA complexes was observed. These results are in agreement with metal bioavailability models and also underline the usefulness of ASV for determining copper bioavailability in the presence of natural organic matter.

Summary The variation from spontaneous mutations for 6-week body weight in the mouse was estimated by selection from a cross of two inbred sublines, C57BL/6 and C57BL/10, separated about 50 years previously from the same inbred line. Selection was practised high and low for 12 generations from the F 2 , followed by one generation of relaxation. The lines diverged by approximately 1·7 g or 0·7 sd. The additive genetic variance was estimated in the F 2 by restricted maximum likelihood and from the selection response, and from this variance the mutational heritability h M 2 was estimated using the number of generations since divergence. Estimates of h M 2 range from 0·08 to 0·10% depending on the method of analysis. These estimates are similar to those found for other species, but lower than other estimates for the mouse. It is concluded that substantial natural and, perhaps, artificial selection operated during the maintenance of the sublines.

Abstract An Ion Chromatographic (IC) method for the determination of six organic acids and three inorganic anions in alkaline solutions was reported. Formic, acetic, propionic, oxalic, succinic, glutaric acid, F ‐ , Cl ‐ , and SO 4 2‐ were separated and determined in 33 min. The analytes were removed from Bayer liquor by using an ion‐exchange resin column. The chromatographic separation was achieved with only one IonPac AS11‐HC column thermostated at 30 °C. Organic acids and inorganic anions were detected with a suppressed conductance detector. The precision results' showed that the repeatability and reproducibility were &lt;2.94 and &lt;1.37 %, respectively. The accuracy of the method was assessed by the recoveries ranging from 86.3 to 105.6 %. Under optimum conditions the detection limits ranged from 0.008 to 0.053 mg/l.

In chronic kidney disease (CKD), the prevalence of hypertension is very high, escalating with diminishing renal function. Typically, the diagnosis of hypertension and the clinical decisions regarding its treatment are based on daytime clinic blood pressure (BP) measurements. However, the correlation between BP level and target organ damage, cardiovascular risk and long-term prognosis is greater for ambulatory than clinic measurements. Moreover, evidence is consistent among numerous studies that the elevated risk and incidence of end-organ injury and fatal and non-fatal cardiovascular events are significantly associated with blunted night-time BP decline, and that the asleep BP better predicts cardiovascular events than either the awake or 24-h BP mean. The prevalence of abnormally high asleep BP is extensive in CKD, significantly increasing with its severity. In CKD, the diagnoses of hypertension and its therapeutic control are often inaccurate in the absence of complete and careful assessment of the entire 24 h, i.e. daytime and night-time, BP pattern. Accordingly, ambulatory BP monitoring should be the preferred method to comprehensively assess and decide the optimal clinical management of patients with CKD. Recent findings indicate therapeutic restoration of normal physiologic BP reduction during night-time sleep is the most significant independent predictor of decreased cardiovascular and cerebrovascular risk, both in patients with and without CKD, and is best achieved when antihypertensive medications, mainly those blocking the renin-angiotensin-aldosterone system, are routinely taken at bedtime.

Genetic risk is a primary contributing factor to the predisposition of a newborn child to elevated blood pressure later in life. To determine if there is a correlation between potential genetic risk as established by family history and measured physiological variables in the neonate, the systolic and diastolic blood pressures and heart rates of 150 newborn babies were automatically monitored at about 30-minute intervals for 48 hours with a Nippon Colin device, starting early after birth. Based on questionnaires given to the parents, the neonates were assigned to a group of either a negative or positive family history of high blood pressure. Circadian characteristics and descriptive statistics for the 3 circulatory variables were used for classification by a "monotest", an all-subsets variable selection technique for biomedical discriminant analysis. For a particular combination of variables, the monotest performs as many separate analyses as the number of subjects, each subject's data being compared with those of all others. When the circadian amplitudes of systolic blood pressure and heart rate and the circadian range of heart rate were used as a combined classifier, the monotest yielded a 70% classification equivalent to prior criteria, the latter being based on the family history of high blood pressure. The combined use of time-specified sampling hardware with signal processing and discriminant analysis software allows one to recognize parameters of blood pressure circadian variability as a source of information for neonatal classification according to cardiovascular risk.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The potential anti-diabetic effect of resveratrol derivative, 3,3′,4,5′-tetramethoxy-trans-stilbene (3,3′,4,5′-TMS) and its underlying mechanism in high glucose (HG) and dexamethasone (DXMS)-stimulated insulin-resistant HepG2 cells (IR-HepG2) were investigated. 3,3′,4,5′-TMS did not reduce the cell viability of IR-HepG2 cells at the concentrations of 0.5–10 µM. 3,3′,4,5′-TMS increased the potential of glucose consumption and glycogen synthesis in a concentration-dependent manner in IR-HepG2 cells. 3,3′,4,5′-TMS ameliorated insulin resistance by enhancing the phosphorylation of glycogen synthase kinase 3 beta (GSK3β), inhibiting phosphorylation of insulin receptor substrate-1 (IRS-1), and activating phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway in IR-HepG2 cells. Furthermore, 3,3′,4,5′-TMS significantly suppressed levels of reactive oxygen species (ROS) with up-regulation of nuclear factor erythroid 2-related factor 2 (Nrf2) expression. To conclude, the beneficial effect of 3,3′,4,5′-TMS against insulin resistance to increase glucose consumption and glycogen synthesis was mediated through activation of IRS/PI3K/Akt signaling pathways in the IR-HepG2 cells, accomplished with anti-oxidative activity through up-regulation of Nrf2.