Effectiveness of photo-ozone therapy against equine Pythium insidiosum

Cutaneous pythiosis is a life-threatening infectious disease. Low-level laser therapy (LLLT) and ozone (O3) have been used individually in the treatment of infected wounds. The goals of the study were a) to characterize the antimicrobial action of the photo-ozone therapy (LLLT-O3) against equine Pythium insidiosum, and b) to assess the cytotoxic potential of the LLLT-O3 in keratinocytes. Specimens of pathogen were isolated from 10 horses. After culturing, 120 hyphae plugs were distributed among four groups (n=30 hyphae plugs/group): LLLT (laser irradiation for 160 sec;), O3 (exposition to O3 for 15 min;), LLLT-O3 (LLLT and O3 treatments in sequence) and control (untreated plugs). The hyphae growth was measured during the first 14 days post-treatment. Where there was an absence of hyphae growth, the plug was recultured for an additional 7 days. The cytotoxic potential of the treatments against HaCaT keratinocytes was assessed by colorimetric assays. The LLLT-O3 and O3 treatments inactivated, respectively, 92.3% (28/30) and 30% (9/30) of the samples. No growth was detected after 7 days reculture of inactivated hyphae plugs on new media. Hyphae growth was visualized in 100% of the control and LLLT hyphae plugs. The viability of HaCaT cells was not affected by the isolated treatments (LLLT and O3), while the LLLT-O3 showed slight cytotoxic effect (20%) when compared to the control group (P<0.05). Photo-ozone therapy inactivated equine P. insidiosum hyphae with minimal cytotoxicity in skin cells in vitro.

Analysis of microbial communities of ocular prostheses and anophthalmic sockets using 16S rRNA gene sequencing

Ocular prostheses are liable to host microbial adhesion, which can favor conjunctival inflammation. Knowing the microbiota of the ocular prosthesis and anophthalmic socket is important for predicting infection-related pathogens. This study evaluated the microbiota of the prostheses and anophthalmic sockets of six individuals by 16S rRNA sequencing. The microbial abundance and diversity were analyzed using the Operational Taxonomic Units at the genus level. Forty-seven phyla, capturing 1,258 named genera, were recorded in the sample set. In both sites, the most frequent genera were Fusobacterium, Staphylococcus, Prevotella, and Streptococcus. The microbial abundance was higher for the anophthalmic socket than for the prosthesis. Alpha diversity showed no significant differences in bacterial richness or diversity between sites. Although the microbial abundance in the anophthalmic socket was higher, both sites had similar microbiota with high diversity and low dominance among the genera.

Loss of Brain-Derived Neurotrophic Factor Mediates Inhibition of Hippocampal Long-Term Potentiation by High-Intensity Sound

Exposure to noise produces cognitive and emotional disorders, and recent studies have shown that auditory stimulation or deprivation affects hippocampal function. Previously, we showed that exposure to high-intensity sound (110 dB, 1 min) strongly inhibits Schaffer-CA1 long-term potentiation (LTP). Here we investigated possible mechanisms involved in this effect. We found that exposure to 110 dB sound activates c-fos expression in hippocampal CA1 and CA3 neurons. Although sound stimulation did not affect glutamatergic or GABAergic neurotransmission in CA1, it did depress the level of brain-derived neurotrophic factor (BDNF), which is involved in promoting hippocampal synaptic plasticity. Moreover, perfusion of slices with BDNF rescued LTP in animals exposed to sound stimulation, whereas BDNF did not affect LTP in sham-stimulated rats. Furthermore, LM22A4, a TrkB receptor agonist, also rescued LTP from sound-stimulated animals. Our results indicate that depression of hippocampal BDNF mediates the inhibition of LTP produced by high-intensity sound stimulation.

Electrodialytic treatment of secondary mining resources for raw materials extraction: Reactor design assessment

The sustainability of mining activities is compromised due to the high amounts of mining residues generated that have to be disposed of, often in open dams, that may cause environmental deterioration, e.g. release of toxic elements to water supplies. These residues are, however, secondary resources of raw materials. In the case of Panasqueira mine, they even are a source of tungsten, considered a critical raw material. The present work aims to assess the electrodialytic process efficiency for raw materials extraction from Panasqueira mine residues. Experiments were performed with 2 and 3-compartment electrodialytic reactors, applying current intensities between 50 and 100 mA, from 4 to 14 days, and sample suspensions enhanced with NaCl or effluent. Additionally, control experiments with no current application were carried out. The results showed that a 3-compartment reactor operating at 100 mA, with NaCl as supporting electrolyte, presented the highest extraction of copper (13%), tin (10%), tungsten (13%) and arsenic (63%).

Electrodialytic removal of tungsten and arsenic from secondary mine resources - Deep eutectic solvents enhancement

Tungsten is a critical raw material for European and U.S. economies. Tungsten mine residues, usually considered an environmental burden due to e.g. arsenic content, are also secondary tungsten resources. The electrodialytic (ED) process and deep eutectic solvents (DES) have been successfully and independently applied for the extraction of metals from different complex environmental matrices. In this study a proof of concept demonstrates that coupling DES in a two-compartment ED set-up enhances the removal and separation of arsenic and tungsten from Panasqueira mine secondary resources. Choline chloride with malonic acid (1:2), and choline chloride with oxalic acid (1:1) were the DES that in batch extracted the average maximum contents of arsenic (16%) and tungsten (9%) from the residues. However, when ED was operated at a current intensity of 100 mA for 4 days, the extraction yields increased 22% for arsenic and 11% for tungsten, comparing to the tests with no current. From the total arsenic and tungsten extracted, 82% and 77% respectively were successfully removed from the matrix compartment, as they electromigrated to the anolyte compartment, from where these elements can be further separated. This achievement potentiates circular economy, as the final treated residue could be incorporated in construction materials production, mitigating current environmental problems in both mining and construction sectors.

Hygiene protocols for the treatment of denture-related stomatitis: local and systemic parameters analysis - a randomized, double-blind trial protocol

Background

Denture-related stomatitis (DS) is chronic multifactorial inflammation, strongly related to the presence of the biofilm that is the complex structure formed by microorganisms held together by a mucus-like matrix of carbohydrate that adheres to different surfaces, including the denture surface. DS has recently been correlated with deleterious cardiovascular alterations. The potential effect of hygiene protocols in the control of DS and randomized clinical trials that address this oral condition with cardiovascular complications are important in clinical decision-making.

Material/design

A clinical trial, randomized, double-blind, and with parallel groups, will be conducted in Brazil The sample will consist of 100 patients without teeth in both arches, users of at least maxillary complete dentures, and diagnosed with DS, who will be allocated to groups (n = 25 per group) according to the different hygiene protocols: (1) brushing of the palate and immersion of the prosthesis in 0.25% sodium hypochlorite solution (positive control); (2) brushing of the palate and immersion of the prosthesis in 0.15% triclosan solution; (3) brushing of the palate and immersion of the prosthesis in lactose monohydrate; or (4) brushing the palate with citric acid and immersing the prosthesis in lactose monohydrate. The response variables will be heart rate variability and alteration of blood pressure (systemic level), remission of DS, removal of biofilm, reduction of microbial load (colony-forming units (CFU)), mouth and prosthesis odor level, expression of MUC1, proinflammatory cytokines, C-reactive protein (CRP), viscosity, pH and salivary flow (locally); patient-centred qualitative analysis will also be undertaken. Measurements will be performed at baseline and 10 days after the interventions. The results obtained will be statistically analyzed as pertinent, with a level of significance of 0.05.

Discussion

This study will provide a guideline for clinical practice regarding the use of hygiene protocols in the treatment of oral diseases (DS) mediated by biofilm. Also, it may provide evidence of correlation of oral manifestation with cardiac risk.

Trial registration

Brazilian Registry of Clinical Trials, RBR-4hhwjb. Registered on 9 November 2018.

Sustainability of construction materials: Electrodialytic technology as a tool for mortars production

The reduction of tap water consumption in all activity sectors, including the building industry, is crucial to the sustainability of water resources. Effluents from wastewater treatment plants have the potential to replace freshwater in the construction sector but they contain a critical mixture of impurities, which hampers their use in mortars production. In this work, the viability of using effluent as an alternative to potable water for the production of mortars, after electrodialytic treatment, was assessed. Electrodialytic technology (ED-T) is a proven technique for decontamination of porous and aqueous matrices. ED-T experiments were conducted with 500 mL of effluent for 6, 12 and 24 h, with a current intensity of 25 mA. The results showed that after ED-T 6 h, the removal efficiencies of critical components were above 85% of their initial concentrations. Mortar properties such as setting time, workability, flexural strength, compressive strength and morphology were obtained for 100% effluent and tap water/effluent mixtures (50:50) with and without ED-T pre-treatment. The mortars with the ED-T treated effluent showed similar initial setting times and workability, higher flexural and compressive strength compared to the mortars reference.

Abstract P285: Carotid Sinus Nerve Stimulation Attenuates Alveolar Bone Loss in Rats With Induced Periodontitis

Introduction: Few studies have focused on the impact of the progression of periodontitis on hypertension. Baroreflex Activation Therapy (BAT) has been used to treat patients with resistant hypertension. Our laboratory has investigated the role of electrical carotid sinus nerve (CSN) stimulation in unanesthetized rats, on local and systemic inflammation. Since periodontitis is a chronic inflammatory disease, the aim of this study was to evaluate the role of the baro- and chemoreflex activation, by means of electrical stimulation of the CSN, on alveolar bone loss in rats with periodontitis.

Methods and Results: Under ketamine/xylazine anesthesia Wistar Hannover rats were implanted with electrodes around the CSN and a catheter inserted into the abdominal aorta for blood pressure recording. After 48h periodontitis was induced by the ligation of the bilateral mandibular first molar, followed by the electrical stimulation of the CSN (1,5-4V, 1ms, 30Hz for 10 min); which was continued during the next eight days. At the 8 th day after the induction of periodontitis, the rats were euthanized and the jaws were resected; besides, microtomographic analysis was performed by bi and three-dimensional quantification using micro-computerized tomography. As compared to baseline results the electrical stimulation of the CSN (N=7) promoted a decrease in mean arterial pressure (108± 8 vs. 91± 5 mmHg; p<0.05) and heart rate (374±10 vs. 319±15 bpm; p<0.05). The CSN stimulated rats (N=7) with periodontitis showed greater bone volume and bone surface than the non-stimulated control rats (N=4) with periodontitis, evaluated by three-dimensional analysis (0.5±0.005 vs. 0.7±0.03 mm 3 ; 16.54±0.22 vs. 23.30±0.66 mm 2 , respectively; p<0.05). Moreover, the CSN stimulated rats with periodontitis presented a decrease of the furcation area and interproximal region as compared to the non-stimulated control rats (1.14±0.06 vs. 0.5±0.07 mm; 3.25±0.03 vs. 2,48±0,13 mm, respectively; p<0.05).

Conclusions: Overall, these results demonstrate that stimulation of the CSNs promotes a protective effect on alveolar bone loss elicited by periodontitis involving the activation of the baro- and chemoreflex.

Antihypertensive Efficacy of Amlodipine and Losartan after Two ‘Missed’ Doses in Patients with Mild to Moderate Essential Hypertension

We compared the effects of amlodipine (5 − 10 mg, n = 94) and losartan (50 − 100 mg, n = 94) on the lowering of blood pressure (BP) at steady state and after two missed doses, as well as on tolerability. This was a randomized, double-blind study of 12 weeks of active treatment followed by 2 days of placebo treatment. Twenty-four-hour ambulatory blood pressure monitoring and office BP measurements were performed at baseline, week 12 and after the 2-day drug holiday. After 12 weeks, amlodipine was significantly more effective than losartan in reducing both 24-h systolic blood pressure (SBP) (−18.0 versus −10.8 mmHg) and diastolic blood pressure (DBP) (−10.6 versus −8.0 mmHg). While mean SBP and DBP for both treatments increased comparably during the drug holiday, BP values remained significantly lower than baseline for both treatments. The superior BP-lowering effect of amlodipine compared with losartan was maintained during the drug holiday.

The Increase in Signaling by Kisspeptin Neurons in the Preoptic Area and Associated Changes in Clock Gene Expression That Trigger the LH Surge in Female Rats Are Dependent on the Facilitatory Action of a Noradrenaline Input

In rodents, kisspeptin neurons in the rostral periventricular area of the third ventricle (RP3V) of the preoptic area are considered to provide a major stimulatory input to the GnRH neuronal network that is responsible for triggering the preovulatory LH surge. Noradrenaline (NA) is one of the main modulators of GnRH release, and NA fibers are found in close apposition to kisspeptin neurons in the RP3V. Our objective was to interrogate the role of NA signaling in the kisspeptin control of GnRH secretion during the estradiol induced LH surge in ovariectomized rats, using prazosin, an α1-adrenergic receptor antagonist. In control rats, the estradiol-induced LH surge at 17 hours was associated with a significant increase in GnRH and kisspeptin content in the median eminence with the increase in kisspeptin preceding that of GnRH and LH. Prazosin, administered 5 and 3 hours prior to the predicted time of the LH surge truncated the LH surge and abolished the rise in GnRH and kisspeptin in the median eminence. In the preoptic area, prazosin blocked the increases in Kiss1 gene expression and kisspeptin content in association with a disruption in the expression of the clock genes, Per1 and Bmal1. Together these findings demonstrate for the first time that NA modulates kisspeptin synthesis in the RP3V through the activation of α1-adrenergic receptors prior to the initiation of the LH surge and indicate a potential role of α1-adrenergic signaling in the circadian-controlled pathway timing of the preovulatory LH surge.

Kisspeptin regulates tuberoinfundibular dopaminergic neurones and prolactin secretion in an oestradiol-dependent manner in male and female rats

Prolactin (PRL) secretion is inhibited by hypothalamic dopamine. Kisspeptin controls luteinising hormone (LH) secretion and is also involved in PRL regulation. We further investigated the effect of kisspeptin-10 (Kp-10) on the activity of tuberoinfundibular dopaminergic (TIDA) neurones and the role of oestradiol (E2 ) in this mechanism. Female and male rats were injected with i.c.v. Kp-10 and evaluated for PRL release and the activity of dopamine terminals in the median eminence (ME) and neurointermediate lobe of the pituitary (NIL). Kp-10 at the doses of 0.6 and 3 nmol increased plasma PRL and decreased 4-dihydroxyphenylacetic acid (DOPAC) levels in the ME and NIL of ovariectomised (OVX), E2 -treated rats but had no effect in OVX. In gonad-intact males, 3 nmol Kp-10 increased PRL secretion and decreased DOPAC levels in the ME but not in the NIL. Castrated males treated with either testosterone or E2 also displayed increased PRL secretion and reduced ME DOPAC in response to Kp-10, whereas castrated rats receiving oil or dihydrotestosterone were unresponsive. By contrast, the LH response to Kp-10 was not E2 -dependent in either females or males. Additionally, immunohistochemical double-labelling demonstrated that TIDA neurones of male rats contain oestrogen receptor (ER)-α, with a higher proportion of neurones expressing ERα than in dioestrous females. The dopaminergic neurones of periventricular hypothalamic nucleus displayed much lower ERα expression. Thus, TIDA neurones express ERα in male and female rats, and kisspeptin increases PRL secretion through inhibition of TIDA neurones in an E2 -dependent manner in both sexes. These findings provide new evidence about the role of kisspeptin in the regulation of dopamine and PRL.

A randomised trial of a simplified method for complete denture fabrication: patient perception and quality

Complete denture fabrication involves a series of complex technical procedures. Nevertheless, simplified methods may be as effective as conventional ones albeit the lesser use of time and resources, without disadvantage for the patient. This study compared a simplified method for complete denture fabrication to a conventional protocol in terms of oral health-related quality of life (OHRQoL), patient satisfaction and denture quality. Forty-two edentulous patients requesting treatment with complete dentures were randomly allocated into two study groups. Group S received dentures fabricated by a simplified method and Group C received conventionally fabricated dentures. Before interventions and after three and 6 months following insertion, OHRQoL and patient satisfaction were analysed by specific instruments. A prosthodontist assessed denture quality 3 months after delivery. Groups presented no difference for OHRQoL, denture quality and general satisfaction. Differences regarding patient satisfaction with some aspects of the dentures were found after 3 months (S > C), but were insignificant at 6 months. It was concluded that the simplified method is able to produce dentures of a quality comparable to those produced by the conventional method, influencing OHRQoL and patient satisfaction similarly.

Cholinesterase inhibition and behavioral toxicity of carbofuran on Oreochromis niloticus early life stages

Nile tilapia Oreochromis niloticus at 9 days post-hatch were exposed in semi-static experiments to the carbamate insecticide carbofuran, which is applied in agricultural systems in Brazil. Although the molecular mechanism of carbofuran toxicity is well known, a detailed understanding of the ecological mechanisms through which carbofuran effects can propagate towards higher levels of biological organization in fish is incomplete. Mortality rates were quantified for larvae exposed for 96 h to 8.3, 40.6, 69.9, 140, 297 and 397 μg/L carbofuran, and the LC(50) 96 h was 214.7 μg/L. In addition, the biochemical biomarker cholinesterase inhibition and behavioral biomarkers related to vision, swimming, prey capture and predator avoidance were quantified in individual larvae, as well as their growth in weight. The behavioral parameters were quantified by analysis of digitally recorded videos of individual larvae within appropriate experimental setups. The activity of the enzyme cholinesterase decreased after exposure to carbofuran with a lowest observed effects concentration (LOEC) of 69.9 μg/L. Visual acuity deficits were detected after carbofuran exposure with a LOEC of 40.6 μg/L. Swimming speed decreased with carbofuran exposure, with a LOEC of 397.6 μg/L. The number of attacks to prey (Daphnia magna nauplii) decreased in larvae exposed to carbofuran, with a LOEC of 397.6 μg/L. Growth in weight was significantly reduced in a dose dependent manner, and all carbofuran groups exhibited a statistically significant decrease in growth when compared to controls (p<0.05). The number of predator attacks necessary to capture larvae decreased after exposure to carbofuran, and the LOEC was 69.9 μg/L. These results show that exposure of sensitive early life stages of tilapia O. niloticus to sublethal concentrations of carbofuran can affect fundamental aspects of fish larval ecology that are relevant to recruitment of fish populations, and that can be better understood by the application of behavioral biomarkers.

Activity of hypothalamic dopaminergic neurones during the day of oestrus: involvement in prolactin secretion

A secretory surge of prolactin occurs on the afternoon of oestrus in cycling rats. Pituitary prolactin is inhibited by dopamine. We evaluated the activity of the neuroendocrine dopaminergic neurones during oestrus and dioestrus, as determined by dopaminergic activity in the median eminence and neurointermediate lobe of the pituitary, as well as Fos-related antigen expression in tyrosine hydroxylase (TH)-immunoreactive (ir) neurones of the arcuate nucleus (ARC) and periventricular nucleus (Pe). During oestrus, the 4-dihydroxyphenylacetic acid/dopamine ratio in the median eminence decreased at 16.00 h, coinciding with the increase in plasma prolactin levels. Similarly, the expression of Fos-related antigen in TH-ir neurones of Pe and rostral-, dorsomedial- and caudal-ARC also decreased at 16.00 h. On dioestrus, 4-dihydroxyphenylacetic acid/dopamine ratio in the median eminence and Fos-related antigen expression in TH-ir neurones of Pe and rostral-ARC decreased at 18.00 h, whereas prolactin levels were unaltered. No variation in dopaminergic activity was found in the neurointermediate lobe of the pituitary on either oestrus or dioestrus. The number of TH-ir neurones in the ARC and parameters of dopaminergic activity were found to be generally lower on oestrus compared to dioestrus. The transitory decrease in the activity of neuroendocrine dopaminergic neurones temporally associated with the prolactin surge on the afternoon of oestrus suggests a role for dopamine in the generation of the oestrous prolactin surge.

Kisspeptin regulates prolactin release through hypothalamic dopaminergic neurons

Prolactin (PRL) is tonically inhibited by dopamine (DA) released from neurons in the arcuate and periventricular nuclei. Kisspeptin plays a pivotal role in LH regulation. In rodents, kisspeptin neurons are found mostly in the anteroventral periventricular and arcuate nuclei, but the physiology of arcuate kisspeptin neurons is not completely understood. We investigated the role of kisspeptin in the control of hypothalamic DA and pituitary PRL secretion in adult rats. Intracerebroventricular kisspeptin-10 (Kp-10) elicited PRL release in a dose-dependent manner in estradiol (E2)-treated ovariectomized rats (OVX+E2), whereas no effect was found in oil-treated ovariectomized rats (OVX). Kp-10 increased PRL release in males and proestrous but not diestrous females. Associated with the increase in PRL release, intracerebroventricular Kp-10 reduced Fos-related antigen expression in tyrosine hydroxylase-immunoreactive (ir) neurons of arcuate and periventricular nuclei in OVX+E2 rats, with no effect in OVX rats. Kp-10 also decreased 3,4-dihydroxyphenylacetic acid concentration and 3,4-dihydroxyphenylacetic acid-DA ratio in the median eminence but not striatum in OVX+E2 rats. Double-label immunofluorescence combined with confocal microscopy revealed kisspeptin-ir fibers in close apposition to and in contact with tyrosine hydroxylase-ir perikarya in the arcuate. In addition, Kp-10 was not found to alter PRL release from anterior pituitary cell cultures regardless of E2 treatment. We provide herein evidence that kisspeptin regulates PRL release through inhibition of hypothalamic dopaminergic neurons, and that this mechanism is E2 dependent in females. These findings suggest a new role for central kisspeptin with possible implications for reproductive physiology.

Influence of autonomic neuropathy upon left ventricular dysfunction in insulin-dependent diabetic patients

BACKGROUND

Diabetic cardiomyopathy is a well-defined complication of diabetes that occurs in the absence of ischemic, vascular, and hypertensive disease.

HYPOTHESIS

The study was undertaken to test the relationship among autonomic neuropathy (AN), 24-h blood pressure (BP) profile, and left ventricular function.

METHODS

Nineteen type-1 diabetic patients underwent autonomic tests and echocardiographic examination. Patients were divided according to the presence (AN+) or absence (AN-) of AN.

RESULTS

In the AN+ group (n = 8), the E/A ratio at echo was lower than in the AN- group (n = 11) (1.1 +/- 0.3 vs. 1.6 +/- 0.3; p < 0.005). Systolic and diastolic BP reductions during sleep were smaller in the AN+ than in the AN- group (6.6 +/- 6.6 vs. 13.0 +/- 4.3%; p < 0.03 for systolic and 12.8 +/- 6.8 vs. 20.0 +/- 4.0% for diastolic BP reduction; p < 0.03, respectively). Considering all patients, the E/A ratio correlated inversely with awake diastolic BP (r - 0.63; p = 0.005); sleep systolic BP (r - 0.48; p = 0.04), and sleep diastolic BP (r - 0.67; p = 0.002). The AN correlated with diastolic interventricular septum thickness (r 0.57; p = 0.01), sleep systolic BP (r 0.45; p = 0.05), sleep diastolic BP (r 0.54; p = 0.02), and correlated inversely with systolic and diastolic sleep BP reduction (r - 0.49; p = 0.03 and r - 0.67; p = 0.002, respectively). Finally, E/A ratio and AN score correlated between themselves (r - 0.6; p = 0.005).

CONCLUSION

Our results suggest that left ventricular diastolic dysfunction may be detected very early in type-1 diabetic patients with AN. Parasympathetic lesion and nocturnal elevations in BP could be the link between AN and diastolic ventricular dysfunction.

Electroremediation of straw and co-combustion ash under acidic conditions

Biomass, such as wood and straw, is currently used in EU as a renewable energy source for energy production and this application is expected to rise in coming years. Combined heat and power installations produce fly ash, which is considered hazardous waste. The fly ash management issue should be addressed before biomass combustion is considered a truly sustainable technology. The electrodialytic process is a remediation technique able to assist the management of fly ash. For this work, straw and co-combustion of wood ash are briefly characterized and their electrodialytic treatment is carried out under acidic conditions. Straw ashes presented high removal rates for Ca, Cu, Cr and particularly for Cd, which has been reduced to a level bellow the established by Danish regulations. Acidification also induced a high dissolution and a lower pH of the ash. Fly ash from co-combustion of wood presents similarities with wood ash alone. However, further characterization should be carried out before any comparison regarding applicable legislation. Under acidic conditions, the electrodialytic treatment was not effective for the co-combustion wood ash. The heavy metals appeared in the least soluble fraction of this ash and lowering the pH of such an alkaline material does not mean sustainability and may hinder its reuse.

Modeling of electrodialytic and dialytic removal of Cr, Cu and As from CCA-treated wood chips

A one-dimensional model is developed for simulating the electrodialytic and dialytic treatment of a saturated bed of wood chips containing chromium, copper and arsenic. The movement of Cr, Cu and As is mathematically modeled taking into account the diffusion transport resulting from the concentration gradients of their compounds and the electromigration of their ionic, simple and complex species during the operation. The model also includes the electromigration of the non-contaminant principal ionic species in the system, H(+) and OH(-), proceeding from the electrolysis at the electrodes, Na(+) and NO(3)(-) used as electrolyte solutions in the electrode compartments, and oxalate ions and protons incorporated with the oxalic acid solution during wood chips incubation. The model simulation also takes into account that OH(-) generated on the cathode, during electrodialytic remediation, is periodically neutralized by addition of nitric acid in the cathode compartment. The anion and cation-exchange membranes are simply represented as ionic filters that preclude the transport of co-ions (the cations and anions respectively) with the exception of H(+), which is retarded but considered to pass through the anion-exchange membrane.

Relationship between Cu and Zn extractable foliar contents and BCR sequential extraction in soil treated with organic amendments

The application of organic wastes to soils, such as municipal solid waste compost (MSWC) or treated urban sewage sludge (USS) is a current practice for maintaining soil organic matter, reclaiming degraded soils and supplying plant nutrients. Since USS and MSWC may contain organic contaminants, heavy metals or pathogens, this practice represents a potential problem to the environment. In the case of heavy metals both bioavailability and toxicity seems to be critically dependent on the chemical form of the element. In this work, a pot experiment was carried out with different levels of MSWC and USS, as well as an inorganic solution of Cu and Zn. The aim was to obtain information about their bioavailability, mobility and toxicity and correlation among the different soil extracted fractions (F1--Exchangeable metal associated with carbonated phases, F2--Reducible metal or associated with Fe and Mn oxides, F3--Oxidizable metal bound to organic matter) with the Cu and Zn foliar (Cu(F) and Zn(F)) and pseudo totals contents (Cu(Ptotal) and Zn(Ptotal)), using the BCR sequential and aqua regia extraction procedure. Both of these methods were adequate to predict the Cu and Zn available to the plant, as high values on the Cu(F)-Cu(sigma123), Cu(F)-Cu(Ptotal), Zn(F)-Zn(sigma123) and Zn(F)-Zn(Ptotal) correlations were verified. Copper bounded mainly to F3, while Zn bounded to F1, F2 and F3 fractions and the regression analysis revelled that Cu and Zn ryegrass absorption were made mainly on F1 and F3 for Cu and F1 for Zn.

Renal risk and renoprotection among ethnic groups with type 2 diabetic nephropathy: a post hoc analysis of RENAAL

Type 2 diabetes is becoming the leading cause of end-stage renal disease (ESRD) worldwide. Prevalence of ESRD and the antihypertensive response to renin-angiotensin system intervention are suggested to vary among different ethnicities. The Reduction in Endpoints in Non-insulin dependent diabetes mellitus with the Angiotensin II Antagonist Losartan (RENAAL) study, which included different ethnic groups, demonstrated a renoprotective effect of losartan. A post hoc analysis from RENAAL was performed where we examined in each ethnic group the ESRD risk, identified independent predictors for ESRD, effect of degree of baseline albuminuria, effect of 6-month antiproteinuric response to therapy on ESRD, and renoprotective effect of losartan assessed by albuminuria reduction and ESRD. Baseline albuminuria was the strongest predictor for ESRD in every ethnic group. Albuminuria reduction was associated with reduced risk of ESRD while losartan reduced albuminuria in every ethnic group. When accounting for independent predictors of ESRD, losartan exhibited renoprotection in all ethnic groups. In this type 2 diabetic population with nephropathy, baseline albuminuria is the predominant risk parameter for ESRD; early antiproteinuric effect of losartan predicts long-term renoprotection; and losartan appears to be renoprotective in all ethnic groups. Since the RENAAL study was not powered to determine ethnic responses, these results underline the need for prospective trials where the aim is renal protection among different ethnic groups.

Removal of organic contaminants from soils by an electrokinetic process: the case of atrazine. Experimental and modeling

The atrazine behaviour in soils when submitted to an electric field was studied and the applicability of the electrokinetic process in atrazine soil remediation was evaluated. Two polluted soils were used, respectively with and without atrazine residues, being the last one spiked. Four electrokinetic experiments were carried out at a laboratory scale. Determination of atrazine residues were performed by enzyme-linked immunosorbent assay (ELISA). The results show that the electrokinetic process is able to remove efficiently atrazine in soil solution, mainly towards the anode compartment: Estimations show that 30-50% of its initial amount is removed from the soil within the first 24h. A one-dimensional model is developed for simulating the electrokinetic treatment of a saturated soil containing atrazine. The movement of atrazine is modelized taking into account the diffusion transport resulting from atrazine concentration gradients and the reversed electro-osmotic flow at acidic soil pH.

Relationship between microalbuminuria and cardiac structural changes in mild hypertensive patients

The aim of this study was to determine the relationship between urinary albumin excretion (UAE), cardiac structural changes upon echocardiography and 24-h ambulatory blood pressure (ABPM) levels. Twenty mild hypertensive patients (mean age 56.8 +/- 9.6 years) were evaluated. After 2 weeks of a washout period of all antihypertensive drugs, all patients underwent an echocardiographic evaluation, a 24-h ABPM and an overnight urine collection. Systolic and diastolic blood pressure during 24-h ABPM was 145 +/- 14/91 +/- 10 mmHg (daytime) and 130 +/- 14/76 +/- 8 mmHg (nighttime), respectively. Seven (35%) patients presented UAE > or = 15 microg/min, and for the whole group, the geometric mean value for UAE was 10.2 x// 3.86 microg/min. Cardiac measurements showed mean values of interventricular septum thickness (IVS) of 11 +/- 2.3 mm, left ventricular posterior wall thickness (PWT) of 10 +/- 2.0 mm, left ventricular mass (LVM) of 165 +/- 52 g, and left ventricular mass index (LVMI) of 99 +/- 31 g/m2. A forward stepwise regression model indicated that blood pressure levels did not influence UAE. Significant correlations were observed between UAE and cardiac structural parameters such as IVS (r = 0.71, P<0.001), PWT (r = 0.64, P<0.005), LVM (r = 0.65, P<0.005) and LVMI (r = 0.57, P<0.01). Compared with normoalbuminuric patients, those who had microalbuminuria presented higher values of all cardiac parameters measured. The predictive positive and negative values of UAE > or = 15 microg/min for the presence of geometric cardiac abnormalities were 75 and 91.6%. These data indicate that microalbuminuria in essential hypertension represents an early marker of cardiac structural damage.

[Manidipine in the treatment of stage I and II essential hypertension patients with overweight or android obesity. A Brazilian multicentre study of efficacy, tolerability and metabolic effects]

OBJECTIVE

To evaluate the efficacy, metabolic effects and tolerability of manidipine used in the treatment of stage I and II essential hypertensive patients with overweight or android obesity.

METHODS

By an open-label, non comparative protocol in 11 Brazilian clinical research centers 102 hypertensive patients of both sexes with over weight or central obesity were treated with manidipine 10 to 20mg once daily for 12 weeks. Blood pressure, heart rate and adverse events were monitored. Fasting plasma glucose, total, HDL and LDL-cholesterol and triglicerides were determined at both placebo period and end of active treatment. Also in 12 patients, insulin sensitivity index was evaluated during placebo and manidipine treatment.

RESULTS

Blood pressure was reduced from 159+/-15 / 102+/-5mmHg to 141+/-15 / 90+/-8mmHg with the treatment without any noticeable change in heart rate. Manidipine-efficacy rate was 71.9% with 51.1% of blood pressure normalization. No significant changes in metabolic parameters were noticed. Tolerability to manidipine was very high and at the last visit 87.1% of the treated patients were free of any adverse event.

CONCLUSION

Manidipine is an adequate, highly effective, exempt of metabolic effects and safe option for treatment of stage I and II essential hypertensive patients with overweight or android obesity.

Treatment of obesity hypertension and diabetes syndrome

Obesity has been shown to be an independent risk factor for coronary heart disease. The insulin resistance associated with obesity contributes to the development of other cardiovascular risk factors, including dyslipidemia, hypertension, and type 2 diabetes. The coexistence of hypertension and diabetes increases the risk for macrovascular and microvascular complications, thus predisposing patients to cardiac death, congestive heart failure, coronary heart disease, cerebral and peripheral vascular diseases, nephropathy, and retinopathy. Body weight reduction increases insulin sensitivity and improves both blood glucose and blood pressure control. Metformin therapy also improves insulin sensitivity and has been associated with decreases in cardiovascular events in obese diabetic patients. Antihypertensive treatment in diabetics decreases cardiovascular mortality and slows the decline in glomerular function. However, pharmacological treatment should take into account the effects of the antihypertensive agents on insulin sensitivity and lipid profile. Diuretics and beta-blockers are reported to reduce insulin sensitivity and increase triglyceride levels, whereas calcium channel blockers are metabolically neutral and ACE inhibitors increase insulin sensitivity. For the high-risk hypertensive diabetic patients, ACE inhibition has proven to confer additional renal and vascular protection. Because hypertension and glycemic control are very important determinants of cardiovascular outcome in obese diabetic hypertensive patients, weight reduction, physical exercise, and a combination of antihypertensive and insulin sensitizers agents are strongly recommended to achieve target blood pressure and glucose levels.

Ultrasonography for the evaluation of visceral fat and cardiovascular risk

Visceral fat accumulation is associated with increased cardiovascular risk. Clinical evaluation of visceral fat is limited because of the lack of reliable and low-cost methods. To assess the correlation between ultrasonography and computed tomography (CT) for the evaluation of visceral fat, 101 obese women, age 50.5+/-7.7 years with a body mass index of 39.2+/-5.4 kg/m(2), were submitted to ultrasonograph and CT scans. Visceral fat measured by ultrasonography, 1 cm above the umbilical knot, showed a high correlation with CT-determined visceral fat (r=0.67, P<0.0001). The ultrasonograph method showed good reproducibility with an intra-observer variation coefficient of <2%. Both ultrasonograph and CT visceral fat values were correlated with fasting insulin (r=0.29 and r=0.27, P<0.01) and plasma glucose 2 hours after oral glucose load (r=0.22 and r=0.34, P<0.05), indicating that ultrasonography is a useful method to evaluate cardiovascular risk. A significant correlation was also found between visceral fat by CT and serum sodium (r=0.18, P<0.05). A ultrasonograph-determined visceral-to-subcutaneous fat ratio of 2.50 was established as a cutoff value to define patients with abdominal visceral obesity. This value also identified patients with higher levels of plasma glucose, serum insulin and triglycerides and lower levels of HDL-cholesterol, which are metabolic abnormalities characteristic of the metabolic syndrome. Our data demonstrate that ultrasonography is a precise and reliable method for evaluation of visceral fat and identification of patients with adverse metabolic profile.

Removal of Cu, Pb and Zn in an applied electric field in calcareous and non-calcareous soils

The pH dependency of the removal of Cu, Zn and Pb by electrodialytic soil remediation from different industrially polluted soils was examined. From 18 experiments performed with five different soils, it was found that the order of mobilization due to a pH decrease was Zn>Cu>Pb. It was found, too, that each of the elements was removed at higher soil pH in calcareous soils (about 12% carbonates) than in soils with a carbonate content of less than 3.7%. In soils rich in carbonates, precipitation of heavy metal carbonates is an important retention mechanism and the heavy metal carbonates are dissolved at higher pH values than the pH at which heavy metals are desorbed in non-calcareous soils. Thus, the relation between the soil pH and the mobility of the heavy metal in the electric field is not only dependent on the heavy metal in focus, but also on the fraction of the heavy metal precipitated as carbonates.

Distribution of cardiac geometric patterns on echocardiography in essential hypertension. Impact of two criteria of stratification

PURPOSE

To evaluate 2 left ventricular mass index (LVMI) normality criteria for the prevalence of left ventricular geometric patterns in a hypertensive population ( HT ).

METHODS

544 essential hypertensive patients, were evaluated by echocardiography, and different left ventricular hypertrophy criteria were applied: 1 - classic : men - 134 g/m2 and women - 110 g/m2; 2- obtained from the 95th percentil of LVMI from a normotensive population (NT).

RESULTS

The prevalence of 4 left ventricular geometric patterns, respectively for criteria 1 and 2, were: normal geometry - 47.7% and 39.3%; concentric remodelying - 25.4% and 14.3%; concentric hypertrophy - 18.4% and 27.7% and excentric hypertrophy - 8.8% and 16.7%, which confered abnormal geometry to 52.6% and 60.7% of hypertensive. The comparative analysis between NT and normal geometry hypertensive group according to criteria 1, detected significative stuctural differences,"( *p < 0.05):LVMI- 78.4 +/- 1.50 vs 85.9 +/-0.95 g/m2 *; posterior wall thickness -8.5 +/- 0.1 vs 8.9 +/- 0.05 mm*; left atrium - 33.3 +/- 0.41 vs 34.7 +/- 0.30 mm *. With criteria 2, significative structural differences between the 2 groups were not observed.

CONCLUSION

The use of a reference population based criteria, increased the abnormal left ventricular geometry prevalence in hypertensive patients and seemed more appropriate for left ventricular hypertrophy detection and risk stratification.

The losartan renal protection study--rationale, study design and baseline characteristics of RENAAL (Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan)

The RENAAL Study is a double-blind, placebo-controlled trial to evaluate the renal protective effects of losartan in Type 2 diabetic patients with nephropathy. The study has enrolled 1513 patients and is expected to continue for 3.5 years after the last patient has been entered. Eligible patients must have a urinary albumin:creatinine ratio of at least 300 mg/g and serum creatinine between 1.3 to 3.0 mg/dL. Eligible hypertensive or normotensive patients are randomised to receive either losartan or placebo, in addition to their existing antihypertensive therapy. Medications that block angiotensin production or action, are excluded. The primary endpoint is a composite of the time to first event of doubling of serum creatinine, end-stage renal disease, or death; secondary endpoints include cardiovascular events, progression of renal disease, and changes in proteinuria; tertiary endpoints include quality of life, healthcare resource utilisation, and amputations. Patients include Caucasians (48.6%), Blacks (15.2%), Asians (16.7%), and Hispanics (18.2%). Baseline urinary albumin:creatinine ratio and serum creatinine levels average 1867 mg/g and 1.9 mg/dL, respectively. Mean systolic and diastolic blood pressures are 153 and 82 mmHg, respectively. RENAAL will document whether blockade of the AII receptor with losartan produces clinical benefits in patients with Type 2 diabetes and nephropathy.

Effect of blood glucose on left ventricular mass in patients with hypertension and type 2 diabetes mellitus

The aim of our prospective study was to evaluate the influence of blood glucose (BG) on left ventricular mass and diastolic function in patients with hypertension and type 2 diabetes mellitus (DM). Fifty-six hypertensive patients with type 2 DM and 26 healthy controls were investigated. They were submitted to echocardiography (ECHO) with Doppler and we calculated the mean of their fasting BG values, office blood pressure (OBP), cholesterol and fractions, and triglycerides during the previous 4 years. The diabetic patients were then followed-up for 1 year with OBP, fasting BG, and lipids measured every 2 months. After this period, the patients were again submitted to ECHO and in 22 patients (group I [GI]), reductions greater than 10% in left ventricular mass index (LVMI) were observed (122 +/- 35 v 89 +/- 23 g/m2, P < .01), whereas increases greater than 10% (group II [GII], n = 17) (94 +/- 18 v 115 +/- 27 g/m2, P < .01) or no changes (group III [GIII], n = 17) (98 +/- 16 v 99 +/- 18 g/m2, NS) in LVMI were detected in the remaining patients. The OBP values did not change during the follow-up. In GI the reduction of LVMI was associated with a BG fall from 178 +/- 36 to 147 +/- 30 mg/dL (P < .01) and a correlation was observed between BG and LVMI percent variations (delta) (r = 0.48, P < .01). No important changes in left ventricular diastolic function were observed during the follow-up. We concluded that the improvement in glycemic control may contribute to LVH regression in hypertensive patients with type 2 DM.

Blood pressure and sympathetic activity in normotensive aviators during short-haul fixed-wings flights

BACKGROUND

In order to evaluate the impact of in-flight stress on BP and sympathetic activity during a short fixed-wing flight, we have studied 18 healthy and normotensive commercial captain aviators, aged 37.5 +/- 4.9 yr.

METHODS

The protocol consisted of a 120-min flight period, divided into segments of pre-flight, take off, mid-cruise, approach and landing, and a 120-min control period. In both flight and control periods, all subjects underwent BP monitoring, heart rate recording and urine collection for catecholamines.

RESULTS

Systolic and diastolic BP (SBP/DBP) were higher during the flight, as a whole, when compared with the control period (134 +/- 11 vs. 121 +/- 8 mmHg, p < 0.05 and 84 +/- 8 vs. 76 +/- 9 mmHg, p < 0.05, respectively). During the flight period, SBP increased in the pre-flight, take-off, approach and landing segments, whereas DBP increased in the take-off, mid-cruise, approach and landing segments. Heart rate did not change in any flight segment. Urinary catecholamines increased during the flight period in comparison to control period 0.20 (0.10 1.8) mg x mg-1 creatinine vs. 0.10 (0.10-1.0) mg x mg-1 creatinine; p < 0.05).

CONCLUSION

We conclude that inflight stress increases BP of the normotensive aviators by sympathetic activation during short-haul flights.

Angiotensin II antagonists for hypertension: are there differences in efficacy?

We compared the antihypertensive efficacy of available drugs in the new angiotensin-II-antagonist (AIIA) class. The antihypertensive efficacy of losartan, valsartan, irbesartan, and candesartan was evaluated from randomized controlled trials (RCT) by performing a metaanalysis of 43 published RCT. These trials involved AIIA compared with placebo, other antihypertensive classes, and direct comparisons between AIIA. A weighted-average for diastolic and systolic blood pressure reduction with AIIA monotherapy, dose titration, and with addition of low-dose hydrochlorothiazide (HCTZ) were calculated. Weighted-average responder rates were also determined. The metaanalysis assessed a total of 11,281 patients. The absolute weighted-average reductions in diastolic (8.2 to 8.9 mm Hg) and systolic (10.4 to 11.8 mm Hg) blood pressure reductions (not placebo-corrected) for AIIA monotherapy were comparable for all AIIA. Responder rates for AIIA monotherapy were 48% to 55%. Dose titration resulted in slightly greater blood pressure reduction and an increase in responder rates to 53% to 63%. AIIA/hydrochlorothiazide combinations produced substantially greater reduction in systolic (16.1 to 20.6 mm Hg) and diastolic (9.9 to 13.6 mm Hg) blood pressure reductions than AIIA monotherapy and responder rates for AIIA/HCTZ combinations were 56% to 70%. This comprehensive analysis shows comparable antihypertensive efficacy within the AIIA class, a near-flat AIIA-dose response when titrating from starting to maximum recommended dose, and substantial potentiation of the antihypertensive effect with addition of HCTZ.

Intima-media thickness evaluation by B-mode ultrasound. Correlation with blood pressure levels and cardiac structures

The aim of this study was to analyze the thickness of the intima-media complex (IMC) using a noninvasive method. The carotid and femoral common arteries were evaluated by noninvasive B-mode ultrasound in 63 normotensive and in 52 hypertensive subjects and the thickness of the IMC was tested for correlation with blood pressure, cardiac structures and several clinical and biological parameters. The IMC was thicker in hypertensive than in normotensive subjects (0.67 +/- 0.13 and 0.62 +/- 0.16 vs 0.54 +/- 0.09 and 0.52 +/- 0.11 mm, respectively, P<0.0001). In normotensive patients, the simple linear regression showed significant correlations between IMC and age, body mass index and 24-h systolic blood pressure for both the carotid and femoral arteries. In hypertensives the carotid IMC was correlated with age and 24-h systolic blood pressure while femoral IMC was correlated only with 24-h diastolic blood pressure. Forward stepwise regression showed that age, body mass index and 24-h systolic blood pressure influenced the carotid IMC relationship (r2 = 0.39) in normotensives. On the other hand, the femoral IMC relationship was influenced by 24-h systolic blood pressure and age (r2 = 0.40). In hypertensives, age and 24-h systolic blood pressure were the most important determinants of carotid IMC (r2 = 0.37), while femoral IMC was influenced only by 24-h diastolic blood pressure (r2 = 0.10). There was an association between carotid IMC and echocardiographic findings in normotensives, while in hypertensives only the left posterior wall and interventricular septum were associated with femoral IMC. We conclude that age and blood pressure influence the intima-media thickness, while echocardiographic changes are associated with the IMC.

Guidelines for treatment of hypertension in Latin America: the Brazilian experience

Treatment of hypertension in most countries of Latin America, in general, follows the recommendations of guidelines generated by both: the National Institute of Health of the United States of America (Joint National Committee) and the World Health Organization together with the International Society of Hypertension. Few countries of Latin America, as Brazil, in the last years have generated their own guidelines for detection, evaluation and treatment of hypertension. Its described the brazilian experience in generates and distributes a guideline for treatment of hypertensive. It is also discussed the difficulties and the needs to a successfully implement the recommendations of guideline for treatment of chronic diseases, such as hypertension.

Risk of linear growth retardation during the first two years of life: a new approach

OBJECTIVE

Estimate the risk of linear growth retardation during the first two years of life as a result of household social vulnerability.

SETTING

Families who participated in the National Supplementary Feeding Program in the Health Units of the metropolitan area of the city of São Paulo, Brazil.

SUBJECTS

Four hundred and thirty-one index-babies, weighing more than 2500 grams and who had at least one young sibling under the age of five who participated in the Program for a minimum of two years.

DESIGN

The index-babies were divided into two cohorts: 74.9% coming from 'non-stunted families' (those with normal height siblings) and 25.1% from 'stunted families' (those with stunted siblings). The study design allowed the observation of growth patterns over a period of time and over a childhood growth range. It also allowed the estimation of the stunting and the recovery probabilities at each moment, not only within a given age range. The transition probabilities between 'stunted' and 'non-stunted' index-babies were estimated. The relative risk ratio (RR) was also calculated.

RESULTS

The prevalence of stunting in the index-babies at 12 and 24 months of age was significantly greater in 'stunted families' (P < 0.001). Probabilities of becoming stunted began to differ from the fourth month on (confidence intervals non-superposed), and were higher for index-babies from 'stunted families'. The recovery probability of a stunted child was smaller in the 'stunted families' cohort after the 12th month of age. From the third month on, the (RR) was always above 1.5.

CONCLUSION

The family context exposes children to failure in growth in the first two years of life when there are already stunted children in the household.

A randomised, double-blind trial comparing mibefradil and amlodipine: two long-acting calcium antagonists with similar efficacy but different tolerability profiles. Mibefradil International Study Group

OBJECTIVE

To compare the efficacy and tolerability of mibefradil and amlodipine in patients with uncomplicated mild-to-moderate essential hypertension.

DESIGN

A double-blind, randomised, parallel group multicentre trial.

METHODS

239 patients received 50 mg mibefradil or 5 mg amlodipine for 4 weeks, followed by a forced titration to 100 mg mibefradil or 10 mg amlodipine for an additional 8 weeks. Patients then entered a 4-week withdrawal period either on therapy or switched to placebo.

RESULTS

Statistically equivalent reductions in trough sitting diastolic blood pressure (SDBP) were observed after 12 weeks of once-daily treatment with 50/100 mg mibefradil (-11.5 +/- 8.2 mm Hg) and 5/10 mg amlodipine (-13.2 +/- 7.9 mm Hg). The number of patients with normalised SDBP (< or = 90 mm Hg) increased 23.3% in the mibefradil group and 19.5% in the amlodipine group (approximately 74% in both groups). Patients on mibefradil or amlodipine during the withdrawal period had significantly larger decreases in SDBP than those on placebo. Patients on mibefradil had a decrease in heart rate of 5.5 bpm. Patients on amlodipine had no change in heart rate; however, cessation of amlodipine was associated with a decrease in heart rate.

CONCLUSIONS

Mibefradil was as effective as amlodipine in reducing BP; both compounds were effective treatments of hypertension.

Role of substance P in blood pressure regulation in salt-dependent experimental hypertension

The participation of substance P in the pathogenesis of five models of experimental hypertension, ie, DOCA-salt, subtotal nephrectomy, one-kidney-one clip renovascular, two-kidney-one clip renovascular, and spontaneous hypertension, was evaluated via an acute infusion of a newly synthesized potent, specific nonpeptide antagonist of substance P at the NK-1 receptor, the agent CP 96,345. In conscious unrestrained rats, CP 96,345 induced significant and sustained increases in mean arterial pressure of DOCA-salt, subtotal nephrectomy, and one-kidney-one clip renovascular hypertensive rats but only small and nonsignificant changes in blood pressure of two-kidney-one clip renovascular and spontaneously hypertensive rats. CP 96,345 had no effect on the blood pressure of sham-treated controls and Wistar-Kyoto rats. This NK-1 receptor antagonist did not significantly affect the heart rate of any experimental model studied. The data suggest that endogenous substance P may act as a partial counterregulatory mechanism against vasoconstriction in models of salt-dependent hypertension.

Altered blood pressure profile, autonomic neuropathy and nephropathy in insulin-dependent diabetic patients

To evaluate the relationship between autonomic neuropathy (AN) and nephropathy we measured 24-h blood pressure (BP) and overnight urinary albumin excretion (UAE) in 38 patients with insulin dependent diabetes mellitus (IDDM). Autonomic function was evaluated by the heart rate response to deep breathing. Valsalva maneuver, heart rate at rest and BP variation with posture. Sympathetic cutaneous reflex was also tested in both inferior and superior limbs. Patients with mean day diastolic BP (DDBP) < or = 90 mmHg without AN (N = 15) compared to 12 normal controls had similar BP values, but compared to those with DDBP < or = 90 mmHg and AN (N = 12) they had lower night diastolic BP (NDBP) (66 +/- 4.8 vs 72 +/- 8.8 mmHg: p < 0.05) and UAE (9.8 +/- 2.3 vs 107.2 +/- 3.5 micrograms/min; p < 0.001). No difference in DDBP was observed between these two diabetic groups (80 +/- 3.9 vs 83 +/- 6.1 mmHg). Of the 11 patients with DDBP > 90 mmHg, only three were free of AN and only two of the eight with AN where free of diabetic nephropathy. The percentage day/night changes in systolic BP were lower in patients with AN (13 vs 7.9%; p < 0.05) and were inversely related to autonomic score, used as an index of the degree of autonomic dysfunction (r = -0.48; p < 0.01) and to UAE (r = -0.39; p < 0.05). Furthermore, UAE correlated with autonomic score (r = 0.69; p < 0.0001) and with NDBP (r = 0.44; p < 0.01). Our results show that AN in IDDM patients is associated with a reduced nocturnal fall in BP and suggest a pathogenic role of autonomic dysfunction in the development of diabetic nephropathy, possibly favoring both BP elevation during the night and increases in intraglomerular pressure.

[Comparative effects of captopril and chlorthalidone on glucose tolerance and insulin levels essential hypertensives]

PURPOSE

To compare the effects of chlortalidone (CL) and captopril (Cp) upon glucose tolerance and serum insulin levels in essential hypertensive patients.

METHODS

Non obese essential hypertensive patients with normal glucose tolerance test (OGTT) and diastolic blood pressure (DBP) > 90 mmHg and < or = 115 mmHg in the seated position were treated, in a randomized fashion, with Cp or CL during 16 weeks, after 16 weeks of placebo. The OGTT was performed after placebo and after active therapy, with serum insulin levels determinations carried out before and 120 minutes after oral glucose load.

RESULTS

Twenty four patients in the CL group and 19 in the Cp concluded the study. Hypocalemia (serum potassium < 3.8mEq/L or serum potassium reductions > or = 0.9mEq/ L) occurred in nine patients of the CL group (CL H). In this group CL therapy induced increments in the area under the curve of glycemia during OGTT (582 vs 610mg/h/dL, p < 0.05) that were not observed in the normocalemic patients of the CL (CLN) or Cp groups. Serum insulin levels during OGTT did not change with active therapy in all three groups. The insulin sensitivity index, however, decreased significantly in the CLH (1.9 vs 1.4; p < 0.05) and CLN (10.1 vs 4.3, p < 0.05) but remained unchanged in the Cp group (3.1 vs 2.5; NS). The insulin response to glucose index increased in the Cp (0.28 vs 0.40; p < 0.05) group but not in the CLH (0.25 vs 0.42; NS) and CLN (0.07 vs 0.24).

CONCLUSION

The antihypertensive therapy with chlortalidone in essential hypertensive patients may result in reductions in the peripheral sensitivity to insulin that can be accompanied by increases in glycemic levels after oral glucose load, particularly in patients who develop hypocalemia. Our results indicate that Cp therapy induces increments in insulin response to glucose without detectable changes in peripheral insulin sensitivity.

Time-and-spatial-multiplexing tree topology for fiber-optic Bragg-grating sensors with interferometric wavelength-shift detection

A combined time-and-spatial-division-multiplexed tree topology with eight fiber-optic Bragg-grating sensors operating at the 830-nm wavelength was constructed and tested for both quasistatic and periodic strain and temperature measurements. The system uses a interferometric wavelength-shift discriminator and incorporates a reference channel for thermal drift compensation in the output. Dynamic sensor sensitivity, as determined by primary noise sources, is evaluated, and numerical results are presented and compared with experimental results.

Calcium channel blockers as inhibitors of angiotensin I-converting enzyme

Using ion-exchange chromatography of dialyzed human urine from healthy and hypertensive patients, we detected two peaks of angiotensin I-converting enzyme (ACE) activity on hippuryl-His-Leu eluted at ionic strengths of 0.7 (F1 peak) and 1.25 (F2 peak) mS. These hydrolytic activities decreased gradually in the urine of patients submitted to isradipine treatment, F2 and F1 disappearing after 12 and 24 hours, respectively. By Western blot analysis, the urine fractions corresponding to both peaks from healthy and untreated patients presenting ACE activity and from treated patients (24 hours) without this activity were recognized by an ACE-specific antibody. These results indicated that ACE was present but inhibited in the urine of isradipine-treated patients. In vitro assays with ACE isolated from human urine and guinea pig plasma demonstrated that the enzyme is inhibited by isradipine and other commercially available calcium channel blockers, such as felodipine, nifedipine, and verapamil. A noncompetitive inhibition was observed with all calcium channel blockers studied. In conclusion, these results suggest that besides the primary effect on calcium channels, the more commonly used calcium channel blockers are also ACE inhibitors. The development of efficient calcium channel blockers with higher ACE inhibitory activity could result in interesting bifunctional antihypertensive drugs.

Cardiovascular effects of a specific nonpeptide antagonist of substance P (NK-1) receptor in DOCA-salt hypertension

The neurotransmitter substance P acts also as a potent vasodilator. Its participation in the pathogenesis of deoxycorticosterone acetate (DOCA)-salt hypertension was evaluated by an acute infusion of a newly synthesized, potent, specific nonpeptide antagonist of substance P at the NK-1 receptor, the agent CP 96,345. In conscious unrestrained rats, CP 96,345 induced significant and sustained increases in mean arterial pressure of DOCA-salt rats but only small, transient, and nonsignificant rises in blood pressure of sham-treated control rats. The rise in blood pressure was not accompanied by changes in heart rate. Maximal blood pressure increase in DOCA-salt rats was 31.7 +/- 14.8 mm Hg. In a second series of experiments, the hemodynamic effects of this antagonist were evaluated under anesthesia in both DOCA-salt and sham-treated control rats by the thermodilution method. During CP 96,345 infusion, sustained increases in cardiac index and stroke volume and decreases in total peripheral resistance were observed in both DOCA-salt and control rats. In DOCA-salt rats, cardiac index rose by 79.4%, while total peripheral resistance fell by 27.9% of the baseline values. In control rats, the changes were smaller (+27.2% and -22.5%, respectively). Stroke volume changed in parallel to cardiac output in both groups. The data suggest that acute blockade of NK-1 receptors increases blood pressure in DOCA-salt rats mainly by an increase in cardiac output. We conclude that endogenous substance P tends to counteract the DOCA-salt-induced elevation of blood pressure by modulating both cardiac output and peripheral resistance.

Serum insulin levels, 24-hour blood pressure profile, and left ventricular mass in nonobese hypertensive patients

In essential hypertensive patients, considered to be insulin-resistant, a blunted decline in nocturnal blood pressure is associated with increased adrenergic tone and left ventricular mass. Since insulin stimulates the sympathetic system, we tested whether insulin resistance and insulinemia influence left ventricular mass and the 24-hour blood pressure profile. We studied 29 nonobese hypertensive patients with office diastolic pressure between 95 and 110 mm Hg and normal oral glucose tolerance test after a 4-month washout period. They were then assigned to M-mode echocardiographic evaluation and 24-hour ambulatory blood pressure monitoring. The glucose and insulin responses to a 75-g oral glucose load were compared with those obtained in 16 weight-matched normotensive control subjects. During the oral glucose tolerance test the hypertensive patients compared with control subjects presented higher levels of glucose at 60 minutes (138.7 +/- 30.3 versus 108.7 +/- 35.7 mg/dL; P < .05) and 90 minutes (114.0 +/- 23.8 versus 94.8 +/- 31.1 mg/dL; P < .05) and insulin at 60 minutes (287.1 +/- 259.4 versus 142.1 +/- 83.9 pmol/L; P < .05). However, peak insulin levels after glucose load did not correlate with ambulatory blood pressure values or left ventricular mass index. Left ventricular mass index showed significant correlation with mean sleeping systolic pressure (rs = 56, P < .05) and diurnal systolic pressure (rs = .37, P < .05) but not with mean diurnal or sleeping diastolic pressures. In conclusion, our results indicate that in nonobese hypertensive patients, insulin resistance does not have any influence on the 24-hour blood pressure profile or on left ventricular mass index.(ABSTRACT TRUNCATED AT 250 WORDS)

Combined spatial- and time-division-multiplexing scheme for fiber grating sensors with drift-compensated phase-sensitive detection

A combined spatial- and time-division-multiplexing topology with drift-compensated high-resolution wavelength-shift detection is reported for fiber Bragg grating sensors. An eight-element grating sensor array is demonstrated based on this topology. A resolution of ~1.2 microepsilon over a range of ~1.5 mepsilon with a measurement bandwidth of 30 Hz (~0.22 microepsilon/ radicalHz) has been achieved for quasi-static strain measurement.

Progressive ladder network topology combining interferometric and intensity fiber-optic-based sensors

Progressive ladder topology is studied by consideration of its properties of power budget and coupler tailoring. Optimization criteria are addressed for lossless and real systems, and their basic characteristics are compared with other topologies. Numerical results are presented, and an experiment is described for the case in which the network supports interferometric and intensity (with referentiation) fiber-optic-based sensors.

Role of bradykinin in insulin sensitivity and blood pressure regulation during hyperinsulinemia

The purpose of these experiments was to determine in normotensive rats the role of endogenous bradykinin, prostaglandins, and nitric oxide in glucose metabolism and blood pressure response to hyperinsulinemia. Normotensive Wistar rats were treated with two different bradykinin antagonists, indomethacin or N omega-nitro-L-arginine methyl ester, concurrently with a euglycemic clamp with insulin infusion rates of 3 or 6 mU/kg per minute. Glucose uptake, steady-state plasma insulin levels, and insulin sensitivity index were determined over 2 hours. Bradykinin inhibition dramatically reduced glucose uptake and insulin sensitivity index during both the lower and higher insulin infusion rates to 30% and 32%, respectively, of values observed in control rats. Inhibition of prostaglandins or nitric oxide did not alter glucose metabolism in these rats. Blood pressure remained unchanged in the control group throughout the clamp but increased significantly in rats submitted to inhibition of bradykinin, prostaglandins, or nitric oxide, suggesting that these vasodilator systems tend to counteract the hypertensive effect of hyperinsulinemia. The counterregulatory component attributable to bradykinin was about twice as great as that attributable to nitric oxide. These findings suggest that insulin infusion in normotensive Wistar rats fails to raise blood pressure because its effects are offset by mobilization of vasodilator mechanisms, such as bradykinin, prostaglandins, and nitric oxide. Bradykinin seems to play the most important homeostatic role under these conditions, because its inhibition significantly reduces insulin sensitivity and allows blood pressure to rise.

[Glucose tolerance test and insulin secretion in patients with essential hypertension. Effect of enalapril]

PURPOSE

To investigate the effects of enalapril upon glucose and insulin metabolism in patients with essential hypertension.

METHODS

After 4 weeks of washout and 2 weeks of placebo therapy, 10 hypertensive patients were treated with enalapril for 12-14 weeks. Intravenous glucose tolerance test (IVGTT) during 182 minutes was performed before and after treatment. Venous blood samples were drawn for glucose and insulin determinations.

RESULTS

Enalapril caused a significant fall on systolic (-19 +/- 3 mmHg) and diastolic (-10 +/- 2 mmHg) blood pressure. During IVGTT, enalapril induced a small decrease in the area under the curve of glucose (placebo 18,966 +/- 732.6 mg/dl.min and enalapril 17,575 +/- 916.1 mg/dl.min) associated with a small increase in the area under the curve of insulin (placebo 3,155 +/- 446.99 mU/ml.min and enalapril 3.577 +/- 393.92 mU/ml.min). A small rise in the disappearance rate of glucose (Kg) was also observed following enalapril (placebo 2.09 +/- 0.33 and enalapril 2.56 +/- 0.53). The insulin responsiveness to glucose increased significantly from 0.16 +/- 0.020 during placebo to 0.21 +/- 0.023 during enalapril. The insulin sensitivity remained unchanged (placebo 1.97 +/- 0.24 and enalapril 1.83 +/- 0.21).

CONCLUSION

In hypertensive patients, the treatment with enalapril induced a small increase (not significant) in glucose tolerance caused by a significant rise in insulin responsiveness to glucose since no modification in insulin sensitivity was observed.