Dual drug-loaded halloysite hybrid-based glycocluster for sustained release of hydrophobic molecules

A dual drug-loaded HNT–CD glycocluster delivery system based on halloysite nanotubes and carbohydrate functionalized cyclodextrin for delivery of natural drugs was developed.

A synergic nanoantioxidant based on covalently modified halloysite–trolox nanotubes with intra-lumen loaded quercetin

Synergic antioxidant activity was achieved by grafting α-tocopherol derivatives on halloysite nanotubes, and by loading quercetin in the inner lumen.

Design of PNIPAAM covalently grafted on halloysite nanotubes as a support for metal-based catalysts

A thermo-responsive polymer (PNIPAAM) was covalently grafted on the external surface of halloysite nanotubes and used as support for palladium nanoparticles for application as catalyst in Suzuki cross coupling in water under microwave irradiation.

Multicavity halloysite-amphiphilic cyclodextrin hybrids for co-delivery of natural drugs into thyroid cancer cells

Multicavity halloysite nanotube materials were employed as simultaneous carriers for two different natural drugs, silibinin and quercetin, at 6.1% and 2.2% drug loadings, respectively. The materials were obtained by grafting functionalized amphiphilic cyclodextrin onto the HNT external surface. The new materials were characterized by FT-IR spectroscopy, SEM, thermogravimetry, turbidimetry, dynamic light scattering and ζ-potential techniques. The interaction of the two molecules with the carrier was studied by HPLC measurements and fluorescence spectroscopy, respectively. The release of the drugs from HNT-amphiphilic cyclodextrin, at two different pH values, was also investigated by means of UV-vis spectroscopy. Biological assays showed that the new complex exhibits anti-proliferative activity against human anaplastic thyroid cancer cell lines 8505C. Furthermore, fluorescence microscopy was used to evaluate whether the carrier was uptaken into 8505C thyroid cancer cell lines. The successful results revealed that the synthesized multicavity system is a material of suitable size to transport drugs into living cells.

Functionalized halloysite multivalent glycocluster as a new drug delivery system

A new design for halloysite nanotube materials was obtained by grafting chemically modified cyclodextrin units onto the nanotube surface. In particular, grafted cyclodextrins were decorated with thiosaccharide pendants, in order to mimic the well-known binding of sugars to proteins and the glyco-cluster effect occurring during cellular recognition events. The obtained materials were characterized by using a combination of varied techniques (FT-IR spectroscopy, thermogravimetric analysis, scanning electron microscopy, dynamic light scattering, turbidimetry), and their potential drug-delivery abilities were tested by studying their interactions with the common naturally occurring anticancer agent curcumin. A suitable model describing the interaction between our materials and curcumin is proposed.

Paediatricians' attitudes toward pain in children with severe cognitive impairment. A regional survey

INTRODUCTION

pain is a frequent and relevant problem in children with severe cognitive impairments. Assessing pain in these patients can be difficult. Specific observational tools such as the Collignon Giusiano Questionnaire or the Non-communicating Children's Pain Checklist ( NCCPC) are available, but their use is not widespread. Children with severe cognitive impairment are frequently in need of painful procedures but data about availability of procedural sedation in this setting are limited.

OBJECTIVE OF THE STUDY

to evaluate paediatricians' attitudes toward pain in children with severe cognitive impairment by measuring the use of specific pain scales and the use of analgesia or procedural sedation in course of a frequent procedure such as botulinum toxin injection.

METHODS

phone interview with the doctor on duty of 56 paediatric wards in 3 regions of the North East of Italy, addressing the routine use of pain scales, and the use of specific observational tools for non communicating children. A phone interview was also conducted in 4 centers routinely practicing botulinum toxin injection about the use of analgesia or procedural sedation.

RESULTS

1 centre out of 55 reported to use specific scales for children with cognitive impairment, specifically the Collignon Giusiano Questionnaire. No centre used procedural sedation for botulinum toxin injection.

CONCLUSION

in the investigated area there is a lack of attention to pain in children with severe cognitive impairment. Specific educational efforts should be done to improve the quality of care in this setting.

Gilles de la Tourette syndrome: clinical features of 75 cases from Argentina

A series of 75 cases of Gilles de la Tourette syndrome (GTS) from Argentina, whose ages ranged from 6 to 55 with a mean of 20.02, were evaluated to compare findings with those reported for other countries. Mean age at onset was 7.44 years and mean overall duration of symptoms was 12.58 years; 6.7% of cases were mild, 49% moderate and 44.3% severe. Most frequent presenting motor tics were excessive blinking in 41 followed by head jerking in 16 and eye winking in six, while phonic tics included coprolalia in 28.0%, echolalia in 17.5% and palilalia in 10.8%. Abnormal perinatal events were reported in 40.5%, while positive family history for tics was present in 26.66%. Obsessive-compulsive behaviour was evident in 66% and attention deficit disorder in 16% of cases. Self-injurious behaviour comprised onychophagia in 28 patients, lip-biting in seven and self-slapping in eight cases. Almost half of our patients were initially interpreted as having a psychogenic disorder indicating that GTS in Argentina is most likely underdiagnosed. It may be concluded that the overall pattern of GTS is not dissimilar to that described for European, Asian and American populations, thus highlighting the previously recognized cross-cultural uniformity.

Agenesis of the fetal corpus callosum: sonographic signs change with advancing gestational age

OBJECTIVES

To assess the presence and degree of indirect signs of agenesis of the corpus callosum (ACC) according to gestational age and determine the percentage of cases in which each sign is present by 24 gestational weeks.

METHODS

We analyzed retrospectively 54 cases of ACC which underwent three-dimensional neurosonography at our unit between January 2005 and December 2012. A single examination was available in 48 cases and six cases were followed up longitudinally, giving a total of 69 examinations. The following variables were assessed: indication for referral, karyotype, width of the atrium and presence/absence of colpocephaly, the cavum septi pellucidi, dorsal cyst and additional central nervous system (CNS) and non-CNS anomalies.

RESULTS

Overall, there were 31 cases of complete ACC (cACC, 42 examinations) and 23 cases of partial ACC (pACC, 27 examinations). The mean gestational age was lower in the cases referred because of anomalies other than ACC than it was in those referred because of ventriculomegaly and/or suspicion of ACC (P < 0.05). Atrial width showed a positive linear correlation with advancing gestational age (P < 0.0001); it was < 10.0 mm in 25/34 (73.5%) examinations < 24 gestational weeks and in 9/35 (25.7%) ≥ 24 weeks (P < 0.001). Colpocephaly was present in 20.6% (7/34) of examinations < 24 weeks and in 68.6% (24/35) of those after 23 weeks (P < 0.05). The cavum septi pellucidi was present and visible at least in part in 17 (63%) of the 27 pACC examinations. In nine of the 27 (33.3%) pACC examinations, there was neither ventriculomegaly nor absence of the cavum septi pellucidi. Associated anomalies were present in 25/54 (46.3%) cases, and in 11 these included or consisted of CNS abnormalities. Karyotype was abnormal in seven of the 40 (17.5%) cases in which it was available.

CONCLUSIONS

In a significant proportion of cases, most of the indirect signs of ACC are either absent or barely visible at the time of the midtrimester screening ultrasound examination. Therefore, ACC may escape diagnosis at midtrimester screening ultrasound. In particular, a third of examinations in fetuses with pACC may not show any abnormality in the transventricular screening view < 24 weeks. The medicolegal implications of such findings are important and should be considered.

Pain in cognitively impaired children: a focus for general pediatricians

Pain in children with cognitive impairment and cerebral palsy is a particularly relevant issue due to its high prevalence and impact on quality of life. We review available evidence about prevalence of pain, causes and specific treatment, recognition and use of specific pain scales, physiology, and consequences of pain in this subset of patients.

CONCLUSIONS

Pain is very common and is a critical determinant of quality of life in children with cognitive impairment and cerebral palsy. The diseases and associated complications that frequently expose these patients to pain can be treated and pain prevented. For patients with communication difficulties, appropriate, effective, validated tools are available and should be used to diagnose pain in itself, to >choose analgesic treatment and to determine effectiveness of these therapies. The level of awareness of pediatricians towards this issue seems to be quite low.

Omega-3 fatty acids, inflammation and angiogenesis: basic mechanisms behind the cardioprotective effects of fish and fish oils

Atherosclerosis is now widely accepted to be an inflammatory disease, characterized by degenerative as well as proliferative changes and extracellular accumulation of lipid and cholesterol, in which an ongoing inflammatory reaction plays an important role both in initiation and progression/destabilization, converting a chronic process into an acute disorder. Neovascularization has also been recognized as an important process for the progression/destabilization of atherosclerotic plaques. In fact, vulnerable atherosclerotic plaques prone to rupture are characterized by an enlarged necrotic core, containing an increased number of vasa vasorum, apoptotic macrophages, and more frequent intraplaque haemorrhage. Various functional roles have been assigned to intimal microvessels, however the relationship between the process of angiogenesis and its causal association with the progression and complications of atherosclerosis are still challenging and controversial. In the past 30 years, the dietary intake of omega-3 (n-3) polyunsaturated fatty acids--mainly derived from fish--has emerged as an important way to modify cardiovascular risk through beneficial effects on all stages of atherosclerosis, including plaque angiogenesis. This review specifically focuses on the modulating effects of n-3 fatty acids on molecular events involved in early and late atherogenesis, including effects on endothelial expression of adhesion molecules, as well as pro-inflammatory and pro-angiogenic enzymes. By accumulating in endothelial membrane phospholipids, omega-3 fatty acids have been shown to decrease the transcriptional activation of several genes through an attenuation of activation of the nuclear factor-kappaB system of transcription factors. This occurs secondary to decreased generation of intracellular reactive oxygen species. This series of investigations configures a clear example of nutrigenomics--i.e., how nutrients may affect gene expression, ultimately affecting a wide spectrum of human diseases.

A PRODUÇÃO CIENTÍFICA SOBRE GERENCIAMENTO EM ENFERMAGEM HOSPITALAR: UMA PESQUISA BIBLIOGRÁFICA

Pesquisa bibliográfica com objetivo de identificar e analisar a produção científica sobre gerenciamento emenfermagem, em hospitais, no Sistema Único de Saúde, no período de 1988-2007. Os dados foram coletados em baseseletrônicas (LILACS e MEDLINE) e registrados em instrumento específico. A população de estudo totalizou 19 publicações.Os artigos foram agrupados por similaridade de conteúdo: aspectos gerenciais do trabalho de enfermagem, 11 artigos(57,8%); ensino de administração em enfermagem, 04 artigos (21,1%) e teorias administrativas na enfermagem, 04 artigos(21,1%). Ações gerenciais do enfermeiro são importantes para a articulação dos profissionais da equipe de enfermagem naorganização do processo de trabalho, buscando qualificar o cuidado aos pacientes, atendendo suas necessidades de saúde.Faz-se presente o desafio de uma visão ampliada das práticas de saúde e do exercício da dimensão gerencial do trabalho emuma perspectiva coletiva, participativa e de co-responsabilização, contribuindo com mudanças no cenário de saúde.

Omega-3 Fatty Acids and the Regulation of Expression of Endothelial Pro-Atherogenic and Pro-Inflammatory Genes

By partially replacing the corresponding omega-6 analogues in membrane phospholipids, omega-3 fatty acids have been shown to decrease the transcriptional activation of genes--e.g., adhesion molecules, chemoattractants, inflammatory cytokines--involved in endothelial activation in response to inflammatory and pro-atherogenic stimuli. This regulation occurs, at least in part, through a decreased activation of the nuclear factor-kappaB system of transcription factors, secondary to decreased generation of intracellular hydrogen peroxide. Such regulation by omega-3 fatty acids is likely linked to the presence of a higher number of double bonds in the fatty acid chain in omega-3 compared with omega-6 fatty acids. By similar mechanisms, omega-3 fatty acids have been recently shown to reduce gene expression of cyclooxygenase-2, an inflammatory gene involved, through the activation of some metalloproteinases, in plaque angiogenesis and plaque rupture. The quenching of gene expression of pro-inflammatory pro-atherogenic genes by omega-3 fatty acids has consequences on the extent of leukocyte adhesion to vascular endothelium, early atherogenesis and later stages of plaque development and plaque rupture, ultimately yielding a plausible comprehensive explanation for the vasculoprotective effects of these nutrients.

Insulin enhances vascular cell adhesion molecule-1 expression in human cultured endothelial cells through a pro-atherogenic pathway mediated by p38 mitogen-activated protein-kinase

AIMS/HYPOTHESIS

Although hyperinsulinaemia in Type 2 diabetes in states of insulin resistance is a risk factor for atherosclerotic vascular disease, underlying mechanisms are poorly understood. We tested the hypothesis that insulin increases monocyte-endothelial interactions, which are implicated in atherosclerosis.

METHODS

We treated human umbilical vein endothelial cells with insulin (10(-10) to 10(-7) mol/l) for 0 to 24 h. To dissect potentially implicated signal transduction pathways, we treated endothelial cells with known pharmacological inhibitors of two distinct insulin signalling pathways: the phosphatidylinositol-3'-kinase (PI3'-kinase) inhibitor wortmannin (3 x 10(-8) to 10(-6) mol/l), involved in insulin-induced endothelial nitric oxide synthase stimulation, and the p38 mitogen-activated protein (p38MAP) kinase inhibitor SB-203580 (10(-7) to 2 x 10(-6) mol/l). We measured adhesion molecule expression by cell surface enzyme immunoassays and U937 monocytoid cell adhesion in rotational adhesion assays.

RESULTS

At pathophysiological concentrations (10(-9) to 10(-7) mol/l), insulin concentration-dependently induced vascular cell adhesion molecule (VCAM)-1 (average increase: 1.8-fold) peaking at 16 h. By contrast, the expression of intercellular adhesion molecule-1 and E-selectin were unchanged. The effect on VCAM-1 was paralleled by increased U937 cell adhesion. In the absence of cytotoxicity, wortmannin significantly potentiated the effect of insulin alone on VCAM-1 surface expression and monocytoid cell adhesion, whereas SB-203580 (10(-6) mol/l) completely abolished such effects.

CONCLUSIONS/INTERPRETATION

These observations indicate that insulin promotes VCAM-1 expression in endothelial cells through a p38MAP-kinase pathway, amplified by the PI3'-kinase blockage. This could contribute to explaining the increased atherosclerosis occurring in subjects with hyperinsulinaemia, or in states of insulin resistance, which feature a defective PI3'-kinase pathway.

Mechanisms for reduction of endothelial activation by oleate: inhibition of nuclear factor-kappaB through antioxidant effects

In a model of early atherogenesis based on cultured endothelial cells, we observed that the incorporation of oleic acid in cellular lipids decreases the stimulated expression of several endothelial adhesion molecules and soluble products typically expressed during endothelial activation and involved in monocyte recruitment. We investigated possible mechanisms for this effect assessing the stimulated induction of nuclear factor-kappaB. In parallel, we also measured glutathione (GSH) content and the activity of antioxidant enzymes after oleate treatment and cytokine stimulation. Oleate prevented the stimulated depletion of GSH without any change in the activity of antioxidant enzymes. These results suggest an antioxidant mechanism by which oleate may exert direct vascular atheroprotective effects.

Vasculoprotective effects of oleic acid: epidemiological background and direct vascular antiatherogenic properties

BACKGROUND AND AIMS

The use of the "Mediterranean diet" as a means of preventing atherosclerotic vascular disease is gaining increasing acceptance. As early as in the late 1950s, it was found that the inhabitants of Greece and Southern Italy had a very low incidence of coronary artery disease and that, among other components, their diets were very rich in oleic acid, the main constituent of the olive oil, making up about 29% of their daily caloric intake. It is now clear that, in addition to its relatively minor effects on cholesterol levels, oleic acid directly interferes with the inflammatory response characterising early atherogenesis due to the endothelial expression of adhesion molecules for circulating monocytes.

RESULTS

In in vitro models of early atherogenesis based on cytokine-stimulated cultured endothelial cells, we have observed that the incorporation of oleic acid in total cell lipids is accompanied by decreased expression of a number of major pro-inflammatory proteins, such as endothelial leukocyte adhesion molecules.

CONCLUSIONS

The results of our investigations indicate that oleic acid has a direct vascular atheroprotective effect, and suggest that it may be possible to prevent atherosclerosis by modulating the vascular response to classical triggers (high levels of cholesterol and the advanced glycation end-products of diabetes) using a strategy that is fundamentally different from, and therefore complementary to, drug-based therapy.

Spontaneous baroreflex modulation of heart rate and heart rate variability during orthostatic stress in tetraplegics and healthy subjects

OBJECTIVE

This study was addressed to investigate the contribution of vagal and sympathetic mechanisms to the genesis of low-frequency (LF) oscillations of RR-interval.

DESIGN

To this aim, we utilized the pathophysiological model of tetraplegics, who have intact vagal afferent and efferent pathways of the baroreceptor reflex arc but interrupted medullary-spinal sympathetic pathways.

METHODS

We studied nine complete, traumatic, tetraplegics (C4-C7, TET) and 10 normally healthy subjects (NR) at rest and during physiological baroreceptors unloading induced by 70 degrees head-up tilt. Autoregressive power spectral analysis was used to investigate RR-interval and systolic arterial pressure (SAP) variabilities. Baroreflex modulation of sinus node was assessed by the spontaneous baroreflex sequences method.

RESULTS

Both at-rest and during-tilt LF and high frequency (HF) components were detected in RR-interval of NR, whereas in TET only the HF component was observed in both conditions (with one exception). Baroreflex sensitivity (BRS) did not significantly differ between TET and NR at rest, and underwent a significant and similar decrease during tilt in both groups, being accompanied in NR by a significant increase in LF relative power. Spectral analysis of SAP provided results similar to RR-interval. Tilt also slowed the centre frequency of the LF components of RR-interval and SAP.

CONCLUSIONS

During unperturbed physiological conditions, a change in efferent vagal activity to the heart from baroreflex stimulation by spontaneous arterial pressure changes, is unlikely to contribute on its own to the genesis of LF heart period oscillations in humans who lack the ability to modulate sympathetic nerve traffic to the heart. However, the possibility that a baroreflex modulation of LF oscillations require an intact sympathetic control should be carefully considered.

Positive and negative feedback mechanisms in the neural regulation of cardiovascular function in healthy and spinal cord-injured humans

BACKGROUND

We tested the hypothesis that in humans, hypertension/tachycardia and hypotension/bradycardia nonbaroreflex sequences that occur within spontaneous arterial pressure (AP) and R-R interval fluctuations are an expression of positive feedback mechanisms neurally regulating the cardiovascular system.

METHODS AND RESULTS

We studied 15 spinal cord-injured (SCI) subjects (8 tetraplegics and 7 paraplegics) and 8 healthy subjects. The occurrence of nonbaroreflex (NBseq) and baroreflex (Bseq) sequences, ie, hypertension-bradycardia and hypotension-tachycardia sequences, was assessed during rest and head-up tilt (HUT). The ratio between Bseq and NBseq (B/NB ratio) was also calculated. In resting conditions, the occurrence of NBseq was significantly lower (P:<0.05) in tetraplegics (7.9+/-1.5) than in paraplegics (16.2+/-3.2) and normal subjects (19.0+/-3.5), whereas the occurrence of Bseq was not significantly different between the 3 groups (38.6+/-11.9 versus 45.4+/-6.0 versus 47.0+/-11.9). In tetraplegics, the B/NB ratio showed a marked, significant decrease (from 8.4+/-4.2 to 1.9+/-0.8, P:<0.05) in response to HUT, whereas in normal subjects, it showed a significant increase (from 3.5+/-0.7 to 9.4+/-2.7, P:<0.05). In paraplegics, the B/NB ratio did not change significantly in response to HUT (from 4.5+/-1.6 to 4.8+/-1.1).

CONCLUSIONS

Our data suggest that nonbaroreflex sequences occur in humans and might represent the expression of an integrated, neurally mediated, feed-forward type of short-term cardiovascular regulation that is able to interact dynamically with feedback mechanisms of baroreflex origin.

Effects of a residential exercise training on baroreflex sensitivity and heart rate variability in patients with coronary artery disease: A randomized, controlled study

BACKGROUND

Myocardial ischemia and infarction impair baroreflex sensitivity (BRS), which when depressed is predictive of future cardiac events after myocardial infarction (MI). The main objective of this study was to determine whether exercise training improves BRS in patients with coronary artery disease.

METHODS AND RESULTS

Ninety-seven male patients with and without a previous MI were recruited after myocardial revascularization surgery and randomized into trained (TR) or untrained (UTR) groups. TR patients underwent a residential exercise program at 85% of maximum heart rate (HRmax) consisting of 2 daily sessions 6 times a week for 2 weeks. Eighty-six patients (45 TR and 41 UTR) completed the study. BRS was assessed at baseline and at the end of the protocol by the spontaneous baroreflex method. The standard deviation of mean R-R interval (RRSD) was also assessed as a measure of heart rate variability. At baseline, there were no significant differences between TR and UTR patients in any variable. In TR patients, BRS increased from 3.0+/-0.3 to 5.3+/-0.7 ms/mm Hg (P:<0.001), RRSD from 18.7+/-1.4 to 23.6+/-1.6 ms (P:<0.01), and R-R interval from 792. 0+/-15.5 to 851.3+/-20.5 ms (P:<0.001). No significant changes occurred in UTR patients. Increases in BRS and RRSD were significant in patients either with or without a previous MI.

CONCLUSIONS

Exercise training increases BRS and heart rate variability in patients with coronary artery disease. Improved cardiac autonomic function might add to the other benefits of exercise training in secondary prevention of ischemic heart disease.

Cerebral arteritis following methylphenidate use

Stroke is a well-documented complication of amphetamine abuse. Methylphenidate, chemically and pharmacologically similar to amphetamines, is widely used in the treatment of attention deficit disorder in children. The possibility of vasculitis connected to methylphenidate should not be surprising. A case is reported of stroke associated with ingestion of methylphenidate in an 8-year-old boy. Family history was negative and other causes of vasculitis were excluded. We draw your attention to the risk of using methylphenidate for a long period of time.

Effects of diet and of dietary components on endothelial leukocyte adhesion molecules

Endothelial-leukocyte adhesion molecules are involved in processes regulating the selective attachment of leukocytes to the vessel wall, which participate in tissue inflammation, atherogenesis, and immunity. There has been recent appreciation that diet or specific dietary components may modulate such processes. Highly unsaturated-- particularly omega-3 -- fatty acids and antioxidants are receiving increasing attention in this regard as potential antiatherogenic and anti-inflammatory agents. The vascular surface expression of endothelial leukocyte molecules can also be reflected by plasma levels of "soluble" adhesion molecules, thus allowing the assessment of the effects of diet and selected dietary components on these processes in vivo.

Tuberous sclerosis associated with MDR1 gene expression and drug-resistant epilepsy

Intractable seizures are the most common manifestation in severe cases of tuberous sclerosis. Multidrug resistance type 1 (MDR1) gene expression is directly linked to the resistance of tumor cells to chemotherapy as the major cause of treatment failure, but it has not been reported in tuberous sclerosis cells nor has the relationship between the MDR1 gene and antiepileptic drugs been described. A 4-month-old female is described with poorly controlled seizures secondary to tuberous sclerosis. The patient was treated with antiepileptic drugs, including phenytoin, phenobarbital, and lorazepam, without improvement of symptoms. Phenytoin blood levels were invariably subtherapeutic and ranged from 0.45 to 3.55 microg/mL, despite several consecutive intravenous loading doses. Surgical treatment with total resection of the brain lesions was performed as a last resort. Immunohistochemical analysis of the resected tissues revealed high levels of P-glycoprotein 170 expression, the product of the MDR1 gene. Both MDR1 gene expression and persistently low phenytoin levels likely share a common pathway liable to induce drug-resistant epilepsy.

Muscle metaboreflex contribution to sinus node regulation during static exercise: insights from spectral analysis of heart rate variability

BACKGROUND

It is currently assumed that during static exercise, central command increases heart rate (HR) through a decrease in parasympathetic activity, whereas the muscle metaboreflex raises blood pressure (BP) only through an increase in sympathetic outflow to blood vessels, because when the metaboreflex activation is maintained during postexercise muscle ischemia, BP remains elevated while HR recovers. We tested the hypotheses that the muscle metaboreflex contributes to HR regulation during static exercise via sympathetic activation and that the arterial baroreflex is involved in the HR recovery of postexercise muscle ischemia.

METHODS AND RESULTS

Eleven healthy male volunteers performed 4-minute static leg extension (SLE) at 30% of maximal voluntary contraction, followed by 4-minute arrested leg circulation (ALC). Autonomic regulation of HR was investigated by spectral analysis of HR variability (HRV), and baroreflex control of heart period was assessed by the spontaneous baroreflex method. SLE resulted in a significant increase in the low-frequency component of HRV that remained elevated during ALC. The normalized high-frequency component of HRV was reduced during SLE and returned to control levels during ALC. Baroreflex sensitivity was significantly reduced during SLE and returned to control levels during ALC when BP was kept elevated above the resting level while HR recovered.

CONCLUSIONS

The muscle metaboreflex contributes to HR regulation during static exercise via a sympathetic activation. The bradycardia that occurs during postexercise muscle ischemia despite the maintained sympathetic stimulus may be explained by a baroreflex-mediated increase in parasympathetic outflow to the sinoatrial node that overpowers the metaboreflex-induced cardiac sympathetic activation.

Direct vascular antiatherogenic effects of oleic acid: a clue to the cardioprotective effects of the Mediterranean diet

Atherosclerosis, the main cause of ischemic heart disease, is a process with relevant inflammatory components, in which LDL-cholesterol, largely emphasized in the last years as a "causal" factor following the improvement in prognosis with cholesterol-lowering agents, is only one of the culprits. Despite the use of new cholesterol-lowering drugs, atherosclerotic vascular disease will likely continue to be the main cause of death in Western countries. Furthermore, the statistical relationship between cholesterol and cardiovascular mortality only explains a relatively minor component of differences in mortality among diverse countries. For these reasons, the interest in preventive approaches complementary or alternative to cholesterol reduction should be one of the main objectives of cardiovascular research in the years to come. Already in the '70s the very low incidence of atherosclerotic diseases in Mediterranean countries (Greece and Southern Italy) and the importance of the "dietary factor" in such protection were noticed. Diets for people in these countries are, among other components, very rich in oleic acid, the main constituent of olive oil, with about 29% of daily caloric intake derived from monounsaturated fatty acids. Oleic acid, besides exerting relatively minor effects on the quantitative and qualitative regulation of cholesterol levels, appears to interfere directly with the inflammatory response that characterizes early atherogenesis. The endothelial expression of adhesion molecules for circulating monocytes, induced by inflammatory cytokines, minimally oxidized LDL and the advanced glycation end-products present in diabetes, substantially contributes to the onset and early progression of atherosclerosis. In an in vitro model of early atherogenesis based on cultured endothelial cells stimulated by cytokines, we observed that the incorporation of oleic acid in total cell lipids--mostly at the expenses of saturated fatty acids--decreases the expression of several endothelial leukocyte adhesion molecules, among which vascular cell adhesion molecule-1, involved in the selective monocyte recruitment in the arterial intima. Oleic acid also determines a parallel reduction in messenger RNA for this molecule, interfering with the activation of the most important transcription factor controlling endothelial activation, nuclear factor-kappa B. Thus, possibly in concert with other more highly unsaturated fatty acids, oleic acid may contribute to the prevention of atherosclerosis also through a modulation of gene expression for endothelial leukocyte adhesion molecules. This series of investigations emphasizes the possibility of preventive interventions in atherosclerosis based on the modulation of vascular response to classical "triggers" (cholesterol, advanced glycation end-products of diabetes), an intervention strategy fundamentally different from--and thereby complementary to--those now more in fashion.

Investigating feed-forward neural regulation of circulation from analysis of spontaneous arterial pressure and heart rate fluctuations

BACKGROUND

Analysis of spontaneous fluctuations in systolic arterial pressure (SAP) and pulse interval (PI) reveals the occurrence of sequences of consecutive beats characterized by SAP and PI changing in the same (+PI/+SAP and -PI/-SAP) or opposite (-PI/+SAP and +PI/-SAP) direction. Although the former reflects baroreflex regulatory mechanisms, the physiological meaning of -PI/+SAP and +PI/-SAP is unclear. We tested the hypothesis that -PI/+SAP and +PI/-SAP "nonbaroreflex" sequences represent a phenomenon modulated by the autonomic nervous system reflecting a feed-forward mechanism of cardiovascular regulation.

METHODS AND RESULTS

We studied anesthetized rabbits before and after (1) complete autonomic blockade (guanethidine+propranolol+atropine, n=13; CAB), (2) sympathetic blockade (guanethidine+propranolol, n=15; SB), (3) parasympathetic blockade (atropine, n=16), (4) sinoaortic denervation (n=10; SAD), and (5) controlled respiration (n=10; CR). Nonbaroreflex sequences were defined as >/=3 beats in which SAP and PI of the following beat changed in the opposite direction. CAB reduced the number of nonbaroreflex sequences (19. 1+/-12.3 versus 88.7+/-36.6, P<0.05), as did SB (25.3+/-11.7 versus 84.6+/-23.9, P<0.001) and atropine (11.2+/-6.8 versus 94.1+/-32.4, P<0.05). SB concomitantly increased baroreflex sensitivity (1.18+/-0. 11 versus 0.47+/-0.09 ms/mm Hg, P<0.01). SAD and CR did not significantly affect their occurrence.

CONCLUSIONS

These results suggest that nonbaroreflex sequences represent the expression of an integrated, neurally mediated, feed-forward type of short-term cardiovascular regulation able to interact dynamically with the feedback mechanisms of baroreflex origin in the control of heart period.

Oleic acid inhibits endothelial activation : A direct vascular antiatherogenic mechanism of a nutritional component in the mediterranean diet

Because oleic acid is implicated in the antiatherogenic effects attributed to the Mediterranean diet, we investigated whether this fatty acid can modulate endothelial activation, ie, the concerted expression of gene products involved in leukocyte recruitment and early atherogenesis. We incubated sodium oleate with human umbilical vein endothelial cells for 0 to 72 hours, followed by coincubation of oleate with human recombinant tumor necrosis factor, interleukin (IL)-1alpha, IL-1beta, IL-4, Escherichia coli lipopolysaccharide (LPS), or phorbol 12-myristate 13-acetate for a further 6 to 24 hours. The endothelial expression of vascular cell adhesion molecule-1 (VCAM-1), E-selectin, and intercellular adhesion molecule-1 was monitored by cell surface enzyme immunoassays or flow cytometry, and steady-state levels of VCAM-1 mRNA were assessed by Northern blot analysis. At 10 to 100 micromol/L for >24 hours, oleate inhibited the expression of all adhesion molecules tested. After a 72-hour incubation with oleate and a further 16-hour incubation with oleate plus 1 microg/mL LPS, VCAM-1 expression was reduced by >40% compared with control. Adhesion of monocytoid U937 cells to LPS-treated endothelial cells was reduced concomitantly. Oleate also produced a quantitatively similar reduction of VCAM-1 mRNA levels on Northern blot analysis and inhibited nuclear factor-kappaB activation on electrophoretic mobility shift assays. Incubation of endothelial cells with oleate for 72 hours decreased the relative proportions of saturated (palmitic and stearic) acids in total cell lipids and increased the proportions of oleate in total cell lipids without significantly changing the relative proportions of polyunsaturated fatty acids. Although less potent than polyunsaturated fatty acids in inhibiting endothelial activation, oleic acid may contribute to the prevention of atherogenesis through selective displacement of saturated fatty acids in cell membrane phospholipids and a consequent modulation of gene expression for molecules involved in monocyte recruitment.

Effect of postural changes on cardiovascular responses to static exercise in hypertensive human beings

OBJECTIVE

In hypertensive patients, exaggerated increases in vascular resistance and arterial blood pressure have been reported on changing posture from supine to upright. In this study we tested the hypothesis that in hypertensive subjects, upright posture induces an increase in the vasoconstrictor and pressor responses to physical exercise.

SUBJECTS AND METHODS

We studied 17 males with mild hypertension and 10 sex- and age-matched normotensives. Each performed three bouts of static handgrip at 30% maximum voluntary contraction for 2 min after 10 min of supine rest and, in sequence, after 10 min of sitting and 10 min of standing. Arterial pressure, heart rate and forearm vascular resistance were measured by Finapres and plethysmography, respectively.

RESULTS

Exercise posture did not affect the mean arterial pressure and heart rate responses to static handgrip. No significant differences in these responses were observed between the hypertensives and the normotensives in any posture. In the hypertensives (n = 12), forearm vascular resistance did not change significantly from resting values during supine and sitting static handgrip but increased significantly during standing static handgrip. In the normotensives, forearm vascular resistance did not change significantly from resting values during static handgrip in any posture. The forearm vascular resistance response to the standing static handgrip was significantly greater in the hypertensives than the normotensives. The algebraic sum of forearm vascular resistance responses to postural change from sitting to standing plus that induced by sitting static handgrip (i.e. additive reflexes) was significantly less than the forearm vascular resistance response to the standing static handgrip (i.e. combined relexes), indicating a facilitatory interaction between exercise and orthostatic stimuli in hypertensives. In contrast, the algebraic sum of the heart rate responses to postural change from sitting to standing plus that induced by sitting static handgrip was significantly greater than the response to standing static handgrip, indicating an inhibitory interaction.

CONCLUSIONS

In hypertensive patients, physiological orthostasis causes an increased vasoconstrictor response to static exercise, but this is opposed by an inhibitory influence on the heart rate response, with the result that the pressor response to static exercise is unaffected by upright posture.

Role of muscular factors in cardiorespiratory responses to static exercise: contribution of reflex mechanisms

We investigated the effects of muscle mass and contraction intensity on the cardiorespiratory responses to static exercise and on the contribution afforded by muscle metaboreflex and arterial baroreflex mechanisms. Ten subjects performed static handgrip at 30% maximal voluntary contraction (MVC) (SHG-30) and one-leg extension at 15% (SLE-15) and 30% (SLE-30) MVC, followed by postexercise circulatory occlusion (PECO). Mean arterial pressure (MAP) and heart rate (HR) responses were greater during SLE-30 than during SHG-30. The difference in MAP was maintained by PECO, and the part of the pressor response maintained by PECO was greater after SLE-30 than after SHG-30 (88.3 +/- 10.6 and 67.8 +/- 12.7%, respectively, P = 0. 02). There were no differences in MAP and HR responses between SHG-30 and SLE-15 trials. Baroreflex sensitivity was maintained during SHG-30 and SLE-15, whereas it was significantly reduced during SLE-30 and recovered back to the resting level during PECO. Minute ventilation and oxygen uptake increased more during SLE-30 than during both SHG-30 and SLE-15 trials. Minute ventilation remained significantly elevated above rest only during PECO following SLE-30. These data suggest that during static exercise the muscle mass and contraction intensity affect 1) the magnitude of the cardiorespiratory responses, 2) the contribution of muscle metaboreflex to the cardiorespiratory responses, and 3) the arterial baroreflex contribution to HR control.

[Epidemiological monitoring of psychological, neurological and sensory handicaps in the 0-24-year-old Abruzzo population (Italy). Preliminary results]

OBJECTIVE

To describe the setting up of the Abruzzo Region (Italy) Service for Prevention and Epidemiological Register of Handicaps, to show prevalence data of occurring diseases and fit regression models aimed at explicating disease occurrence in terms of risk factors; to discuss services access data in terms of their efficacy in fitting social and health needs.

SETTING AND DESIGN

We managed data obtained from a regional information system, based upon primary information sources operating in the Local Health Agencies (i.e. school medicine services, general practitioners, paediatricians, familiar counseling services, rehabilitation centers) and specialistic structures for diagnostic detection (multidisciplinary school équipes, hospital division of infant neuropsychiatry, outpatient infant neuropsychiatry services). The data managing model is a population-based epidemiological register. The target population is the 0-24 years population of the Abruzzo Region.

MAIN OUTCOME MEASURES

Occurrence data are expressed as prevalence rates, using standardisation according to the global population of the area of interest. Diagnoses have been defined according to the standard ICD-9 and ICD-10 criteria; definition of handicaps has been made according to the WHO classification (1981). Association between indicator (socio-demographic and anamnestic) variables and occurrence of disease has been fitted by logistic regression models.

RESULTS

Prevalence estimates obtained for the main infant neuropsychiatric diseases, as well as for the main handicap-determining genetic and/or congenital diseases, are consistent with the findings of literature in similar settings. An exception is the high occurrence of hyperkinetic disorders in both sexes. Rehabilitation is the main health need for all diagnostic axes. With respect to social needs, school and home personal care seem to be scarcely relevant if related to disease prevalence. Logistic regression analysis indicates socio-economic status and presence of handicapped relatives in the family as factors associated with the occurrence of disease. Respectively, the two factors are negatively associated with the occurrence of hyperkinetic disorders and positively associated with occurrence of mental retardation. Moreover, living in a natural family is negatively associated with evolutive disorders.

CONCLUSIONS

This is a report about the preliminary results obtained by a specialised register for infant psychological and neurological handicaps. The findings suggest, as operating indications, the standardisation of diagnostic procedures and the definition of common managing guidelines in different areas. Anyhow, the findings of this report highlight the importance of an epidemiological knowledge of handicap in order to design correct prevention strategies and health services planning.

[Spontaneous baroreflex control of heart rate during chronic tandropril therapy]

Differently from other vasodilators, the antihypertensive effect of ACE-inhibitors is not accompanied by an increase in resting heart rate which suggests a modulatory action of these drugs on arterial baroreflex control of heart rate. It is debated whether this modulation involve, an increase in gain (or sensitivity) of baroreflex mechanisms controlling heart rate or is due to a baroreflex control resetting. In this study we investigated the arterial baroreflex control of heart rate both in supine rest and during active standing before and after 7 and 30 days of treatment with a new ACE-inhibitor, trandolapril (2 mg per os oid) in 15 mild hypertensive patients. Baroreflex control of heart rate has been dynamically and non-invasively assessed by analysis of the continuous relationship between beat-to-beat spontaneous fluctuations in systolic blood pressure and pulse interval. By this method, sequences of 3 or more consecutive beats in which systolic blood pressure and pulse interval change in the same direction (either increasing or decreasing) are identified and a linear regression is applied to each individual sequence. The mean individual slope of the systolic blood pressure/pulse interval ratio obtained by averaging all slopes computed within a given period, is calculated and taken as an estimate of the spontaneous baroreflex sensitivity for that period. Trandolapril reduced resting blood pressure significantly (from 147.5 +/- 3.3/95.3 +/- 1.5 to 129.5 +/- 3.7/83.6 +/- 1.6 and 126.6 +/- 3.9/84.5 +/- 1.7 mmHg after 7 e 30 days, respectively) without affecting heart rate. The treatment did not alter baroreflex sensitivity but resulted in an apparent leftward shift of the regression line relating systolic blood pressure to pulse interval along the pressure axis, reflecting the lower prevailing level of arterial pressure. The increases in heart rate and blood pressure induced by standing in control conditions were not significantly modified by trandolapril. Baroreflex sensitivity was significantly reduced by standing both in control conditions and, to the same extent, during treatment. These results suggest that ACE-inhibition does not alter the gain of the integrated baroreflex mechanisms controlling heart rate, but results in a baroreflex resetting that may explain the lack of tachycardia normally observed during antihypertensive therapy with ACE-inhibitors.