Retinal toxicity of heavy metals and its involvement in retinal pathology

The objective of the present review is to discuss epidemiological evidence demonstrating the association between toxic metal (Cd, Pb, Hg, As, Sn, Ti, Tl) exposure and retinal pathology, along with the potential underlying molecular mechanisms. Epidemiological studies demonstrate that Cd, and to a lesser extent Pb exposure, are associated with age-related macular degeneration (AMD), while the existing evidence on the levels of these metals in patients with diabetic retinopathy is scarce. Epidemiological data on the association between other toxic metals and metalloids including mercury (Hg) and arsenic (As), are limited. Clinical reports and laboratory in vivo studies have shown structural alterations in different layers of retina following metal exposure. Examination of retina samples demonstrate that toxic metals can accumulate in the retina, and the rate of accumulation appears to increase with age. Experimental studies in vivo and in vitro studies in APRE-19 and D407 cells demonstrate that toxic metal exposure may cause retinal damage through oxidative stress, apoptosis, DNA damage, mitochondrial dysfunction, endoplasmic reticulum stress, impaired retinogenesis, and retinal inflammation. However, further epidemiological as well as laboratory studies are required for understanding the underlying molecular mechanisms and identifying of the potential therapeutic targets and estimation of the dose-response effects.

Manganese in autism spectrum disorder and attention deficit hyperactivity disorder: The state of the art

The objective of the present narrative review was to synthesize existing clinical and epidemiological findings linking manganese (Mn) exposure biomarkers to autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD), and to discuss key pathophysiological mechanisms of neurodevelopmental disorders that may be affected by this metal. Existing epidemiological data demonstrated both direct and inverse association between Mn body burden and ASD, or lack of any relationship. In contrast, the majority of studies revealed significantly higher Mn levels in subjects with ADHD, as well as direct relationship between Mn body burden with hyperactivity and inattention scores in children, although several studies reported contradictory results. Existing laboratory studies demonstrated that impaired attention and hyperactivity in animals following Mn exposure was associated with dopaminergic dysfunction and neuroinflammation. Despite lack of direct evidence on Mn-induced neurobiological alterations in patients with ASD and ADHD, a plethora of studies demonstrated that neurotoxic effects of Mn overexposure may interfere with key mechanisms of pathogenesis inherent to these neurodevelopmental disorders. Specifically, Mn overload was shown to impair not only dopaminergic neurotransmission, but also affect metabolism of glutamine/glutamate, GABA, serotonin, noradrenaline, thus affecting neuronal signaling. In turn, neurotoxic effects of Mn may be associated with its ability to induce oxidative stress, apoptosis, and neuroinflammation, and/or impair neurogenesis. Nonetheless, additional detailed studies are required to evaluate the association between environmental Mn exposure and/or Mn body burden and neurodevelopmental disorders at a wide range of concentrations to estimate the potential dose-dependent effects, as well as environmental and genetic factors affecting this association.

Modulation of gut microbiota with probiotics as a strategy to counteract endogenous and exogenous neurotoxicity

The existing data demonstrate that probiotic supplementation affords protective effects against neurotoxicity of exogenous (e.g., metals, ethanol, propionic acid, aflatoxin B1, organic pollutants) and endogenous (e.g., LPS, glucose, Aβ, phospho-tau, α-synuclein) agents. Although the protective mechanisms of probiotic treatments differ between various neurotoxic agents, several key mechanisms at both the intestinal and brain levels seem inherent to all of them. Specifically, probiotic-induced improvement in gut microbiota diversity and taxonomic characteristics results in modulation of gut-derived metabolite production with increased secretion of SFCA. Moreover, modulation of gut microbiota results in inhibition of intestinal absorption of neurotoxic agents and their deposition in brain. Probiotics also maintain gut wall integrity and inhibit intestinal inflammation, thus reducing systemic levels of LPS. Centrally, probiotics ameliorate neurotoxin-induced neuroinflammation by decreasing LPS-induced TLR4/MyD88/NF-κB signaling and prevention of microglia activation. Neuroprotective mechanisms of probiotics also include inhibition of apoptosis and oxidative stress, at least partially by up-regulation of SIRT1 signaling. Moreover, probiotics reduce inhibitory effect of neurotoxic agents on BDNF expression, on neurogenesis, and on synaptic function. They can also reverse altered neurotransmitter metabolism and exert an antiamyloidogenic effect. The latter may be due to up-regulation of ADAM10 activity and down-regulation of presenilin 1 expression. Therefore, in view of the multiple mechanisms invoked for the neuroprotective effect of probiotics, as well as their high tolerance and safety, the use of probiotics should be considered as a therapeutic strategy for ameliorating adverse brain effects of various endogenous and exogenous agents.

Role of vitamins beyond vitamin D3 in bone health and osteoporosis (Review)

The objective of the present review was to summarize the molecular mechanisms associated with the effects of the vitamins A, C, E and K, and group B vitamins on bone and their potential roles in the development of osteoporosis. Epidemiological findings have demonstrated an association between vitamin deficiency and a higher risk of developing osteoporosis; vitamins are positively related to bone health upon their intake at the physiological range. Excessive vitamin intake can also adversely affect bone formation, as clearly demonstrated for vitamin A. Vitamins E (tocopherols and tocotrienols), K2 (menaquinones 4 and 7) and C have also been shown to promote osteoblast development through bone morphogenetic protein (BMP)/Smad and Wnt/β‑catenin signaling, as well as the TGFβ/Smad pathway (α‑tocopherol). Vitamin A metabolite (all‑trans retinoic acid) exerts both inhibitory and stimulatory effects on BMP‑ and Wnt/β‑catenin‑mediated osteogenesis at the nanomolar and micromolar range, respectively. Certain vitamins significantly reduce receptor activator of nuclear factor kappa‑B ligand (RANKL) production and RANKL/RANK signaling, while increasing the level of osteoprotegerin (OPG), thus reducing the RANKL/OPG ratio and exerting anti‑osteoclastogenic effects. Ascorbic acid can both promote and inhibit RANKL signaling, being essential for osteoclastogenesis. Vitamin K2 has also been shown to prevent vascular calcification by activating matrix Gla protein through its carboxylation. Therefore, the maintenance of a physiological intake of vitamins should be considered as a nutritional strategy for the prevention of osteoporosis.

Identification of the bacterial metabolite aerugine as potential trigger of human dopaminergic neurodegeneration

The causes of nigrostriatal cell death in idiopathic Parkinson's disease are unknown, but exposure to toxic chemicals may play some role. We followed up here on suggestions that bacterial secondary metabolites might be selectively cytotoxic to dopaminergic neurons. Extracts from Streptomyces venezuelae were found to kill human dopaminergic neurons (LUHMES cells). Utilizing this model system as a bioassay, we identified a bacterial metabolite known as aerugine (C10H11NO2S; 2-[4-(hydroxymethyl)-4,5-dihydro-1,3-thiazol-2-yl]phenol) and confirmed this finding by chemical re-synthesis. This 2-hydroxyphenyl-thiazoline compound was previously shown to be a product of a wide-spread biosynthetic cluster also found in the human microbiome and in several pathogens. Aerugine triggered half-maximal dopaminergic neurotoxicity at 3-4 µM. It was less toxic for other neurons (10-20 µM), and non-toxic (at <100 µM) for common human cell lines. Neurotoxicity was completely prevented by several iron chelators, by distinct anti-oxidants and by a caspase inhibitor. In the Caenorhabditis elegans model organism, general survival was not affected by aerugine concentrations up to 100 µM. When transgenic worms, expressing green fluorescent protein only in their dopamine neurons, were exposed to aerugine, specific neurodegeneration was observed. The toxicant also exerted functional dopaminergic toxicity in nematodes as determined by the "basal slowing response" assay. Thus, our research has unveiled a bacterial metabolite with a remarkably selective toxicity toward human dopaminergic neurons in vitro and for the dopaminergic nervous system of Caenorhabditis elegans in vivo. These findings suggest that microbe-derived environmental chemicals should be further investigated for their role in the pathogenesis of Parkinson's disease.

Mitochondria in the Spotlight: C. elegans as a Model Organism to Evaluate Xenobiotic-Induced Dysfunction

Mitochondria play a crucial role in cellular respiration, ATP production, and the regulation of various cellular processes. Mitochondrial dysfunctions have been directly linked to pathophysiological conditions, making them a significant target of interest in toxicological research. In recent years, there has been a growing need to understand the intricate effects of xenobiotics on human health, necessitating the use of effective scientific research tools. Caenorhabditis elegans (C. elegans), a nonpathogenic nematode, has emerged as a powerful tool for investigating toxic mechanisms and mitochondrial dysfunction. With remarkable genetic homology to mammals, C. elegans has been used in studies to elucidate the impact of contaminants and drugs on mitochondrial function. This review focuses on the effects of several toxic metals and metalloids, drugs of abuse and pesticides on mitochondria, highlighting the utility of C. elegans as a model organism to investigate mitochondrial dysfunction induced by xenobiotics. Mitochondrial structure, function, and dynamics are discussed, emphasizing their essential role in cellular viability and the regulation of processes such as autophagy, apoptosis, and calcium homeostasis. Additionally, specific toxins and toxicants, such as arsenic, cadmium, and manganese are examined in the context of their impact on mitochondrial function and the utility of C. elegans in elucidating the underlying mechanisms. Furthermore, we demonstrate the utilization of C. elegans as an experimental model providing a promising platform for investigating the intricate relationships between xenobiotics and mitochondrial dysfunction. This knowledge could contribute to the development of strategies to mitigate the adverse effects of contaminants and drugs of abuse, ultimately enhancing our understanding of these complex processes and promoting human health.

Association between Heavy Metals, Metalloids and Metabolic Syndrome: New Insights and Approaches

Metabolic syndrome (MetS) is an important public health issue that affects millions of people around the world and is growing to pandemic-like proportions. This syndrome is defined by the World Health Organization (WHO) as a pathologic condition characterized by abdominal obesity, insulin resistance, hypertension, and hyperlipidemia. Moreover, the etiology of MetS is multifactorial, involving many environmental factors, including toxicant exposures. Several studies have associated MetS with heavy metals exposure, which is the focus of this review. Environmental and/or occupational exposure to heavy metals are a major risk, contributing to the development of chronic diseases. Of particular note, toxic metals such as mercury, lead, and cadmium may contribute to the development of MetS by altering oxidative stress, IL-6 signaling, apoptosis, altered lipoprotein metabolism, fluid shear stress and atherosclerosis, and other mechanisms. In this review, we discuss the known and potential roles of heavy metals in MetS etiology as well as potential targeted pathways that are associated with MetS. Furthermore, we describe how new approaches involving proteomic and transcriptome analysis, as well as bioinformatic tools, may help bring about an understanding of the involvement of heavy metals and metalloids in MetS.

Toxic Effects Induced by Diuron and Its Metabolites in Caenorhabditis elegans

The toxicity of diuron herbicide and its metabolites has been extensively investigated; however, their precise toxic mechanisms have yet to be fully appreciated. In this context, we evaluated the toxic mechanism of diuron, 3,4-dichloroaniline (DCA) and 3-(3,4-dichlorophenyl)-1-methylurea (DCPMU), using Caenorhabditis elegans (C. elegans) in the L1 larval stage. For this purpose, worms were acutely exposed to the test chemicals with a preliminary concentration range of 0.5 to 500 μM and first analyzed for lethality (%). Next, the highest concentration (500 μM) was considered for survival (%), reactive oxygen and nitrogen species (RONS), glutathione (GSH) and ATP levels, autophagy index, behavior, and dopaminergic neurodegeneration parameters. Interestingly, increased lethality (%) was found for all chemicals at the higher concentrations tested (100 and 500 μM), with significant differences at 500 μM DCA (p < 0.05). A decrease in the median survival was observed mainly for DCA. Although no changes were observed in RONS production, GSH levels were significantly increased upon diuron and DCA treatment, likely reflecting an attempt to restore the redox status. Moreover, diuron and its metabolites impaired ATP levels, suggesting an alteration in mitochondrial function. The latter may trigger autophagy as an adaptive survival mechanism, but this was not observed in C. elegans. Dopaminergic neurotoxicity was observed upon treatment with all the tested chemicals, but only diuron induced alterations in the worms' locomotor behavior. Combined, these results indicate that exposure to high concentrations of diuron and its metabolites elicit distinct adverse outcomes in C. elegans, and DCA in particular, plays an important role in the overall toxicity observed in this experimental model.

Caenorhabditis elegans as a Model to Study Manganese-Induced Neurotoxicity

Caenorhabditis elegans (C. elegans) is a nematode present worldwide. The worm shows homology to mammalian systems and expresses approximately 40% of human disease-related genes. Since Dr. Sydney Brenner first proposed C. elegans as an advantageous experimental worm-model system for genetic approaches, increasing numbers of studies using C. elegans as a tool to investigate topics in several fields of biochemistry, neuroscience, pharmacology, and toxicology have been performed. In this regard, C. elegans has been used to characterize the molecular mechanisms and affected pathways caused by metals that lead to neurotoxicity, as well as the pathophysiological interrelationship between metal exposure and ongoing neurodegenerative disorders. Several toxic metals, such as lead, cadmium, and mercury, are recognized as important environmental contaminants, and their exposure is associated with toxic effects on the human body. Essential elements that are required to maintain cellular homeostasis and normal physiological functions may also be toxic when accumulated at higher concentrations. For instance, manganese (Mn) is a trace essential element that participates in numerous biological processes, such as enzymatic activities, energy metabolism, and maintenance of cell functions. However, Mn overexposure is associated with behavioral changes in C. elegans, which are consistent with the dopaminergic system being the primary target of Mn neurotoxicity. Caenorhabditis elegans has been shown to be an important tool that allows for studies on neuron morphology using fluorescent transgenic worms. Moreover, behavioral tests may be conducted using worms, and neurotransmitter determination and related gene expression are likely to change after Mn exposure. Likewise, mutant worms may be used to study molecular mechanisms in Mn toxicity, as well as the expression of proteins responsible for the biosynthesis, transport, storage, and uptake of dopamine. Furthermore, this review highlights some advantages and limitations of using the experimental model of C. elegans and provides guidance for potential future applications of this model in studies directed toward assessing for Mn neurotoxicity and related mechanisms.

Developmental lead exposure affects dopaminergic neuron morphology and modifies basal slowing response in Caenorhabditis elegans: effects of ethanol

Lead (Pb) and ethanol (EtOH) are neurotoxicants that affect the dopaminergic (DAergic) system. We first sought to assess the morphology of the DAergic neurons in the Caenorhabditis elegans BY200 strain. The results demonstrated dose-dependent damage in these neurons induced by developmental Pb exposure. Secondly, transgenic worms exposed to 24μM Pb and administered with 200mM EtOH were evaluated in the basal slowing response (BSR). Pb induced impairment in the BSR in the wild-type strain that did not improve in response to EtOH, an effect also observed in strains that lack the DOP-1, DOP-2, and DOP-3 receptors. The animals that overexpress tyrosine hydroxylase (TH), or lack the vesicular transport (VMAT) showed a Pb-induced impairment in the BSR that seemed to improve after EtOH. Interestingly, a dramatic impairment in the BSR was observed in the Pb group in strains lacking the DOP-4 receptor, resembling the response of the TH-deficient strain, an effect that in both cases showed a non-significant reversal by EtOH. These results suggest that the facilitatory effect of EtOH on the impaired BSR observed in Pb-exposed null mutant strains may be the result of a compensatory effect in the altered DAergic synapse present in these animals.

Iron overload and neurodegenerative diseases: What can we learn from Caenorhabditis elegans?

Iron (Fe) is an essential trace element required for several physiological processes. It plays important roles in mitochondrial function, synthesis, and metabolism of the neurotransmitter, as well as oxygen transport. However, excess Fe can cause toxicity. Particularly, Fe overload may result in neurotoxicity, contributing to the development and progression of neurodegenerative diseases, although the molecular mechanisms underlying Fe-induced neurodegeneration have yet to be entirely understood. Alternative (non-rodent) experimental models have been pointed as important approaches to elucidate molecular and physiological events mediating Fe-induced pathology. Among such alternative strategies, an advantageous experimental worm-model system, Caenorhabditis elegans ( C. elegans), has been used to investigate Fe-induced neurotoxicity and neurodegenerative disorders. Its genome has been fully sequenced, corroborating that it shares significant homology with mammalians, and has approximately 40% of human disease-related genes. As part of this review, we discuss studies using the C. elegans model to study molecular mechanisms such as oxidative stress, mitochondrial dysfunction, disturbed homeostasis, and its potential contribution to the study of metal-induced neurodegenerative diseases such as Parkinson’s disease (PD) and Alzheimer’s disease (AD).

One-year follow-up of continuous aspiration mechanical thrombectomy for the management of intermediate-high and high-risk pulmonary embolism: what is the line between utility and futility?

Introduction

Percutaneous catheter-directed treatments have emerged at the last decade for the management of acute high- or intermediate-high-risk pulmonary embolism (PE). Good short-term efficacy and safety have been published, but there are limited data regarding medium- to long-term outcomes.

Purpose

This study aimed to evaluate 1-year all-cause mortality of acute high- and intermediate-high-risk PE patients (pts) treated with continuous aspiration mechanical thrombectomy.

Methods

Twenty-nine consecutive pts with acute central PE (mean age 67.2±14.4 years; 72.4% female; 24.1% active cancer; Charlson comorbidity index 4.5±2.1; 82.8% in class&gt;III of original PESI score; 44.8% high-risk PE) were treated with the Indigo Mechanical Thrombectomy System (Penumbra, Inc) between 03/2018 and 03/2020. Clinical success was defined as improvement in hemodynamic and/or oxygenation parameters or pulmonary hypertension or right heart strain at 48 hours after intervention plus survival to hospital discharge. Data regarding severe adverse events potentially related to the procedure, in-hospital and 1-year all-cause mortality were collected.

Results

Clinical success was 75.9%, with a significant improvement in mean paO2/fiO2 ratio (+77.1±103.2; p&lt;0.01), shock index (−0.4±0.4, p&lt;0.01), need for aminergic support (−75.0%, p&lt;0.01), right ventricular function (66.6%, p&lt;0.01) and systolic pulmonary arterial pressure (−10.2±11.5mmHg, p&lt;0.01) at 48 hours after procedure. In-hospital survival rate was 82.8% but severe adverse events potentially related to the procedure occurred in 3 pts (10.3%). One-year follow-up was completed in 93.1% of cases and all-cause mortality rate was 34.5% (n=10 of which half occurred during the index hospital stay). Higher scores of Charlson comorbidity index (5.8±1.9 vs 3.7±1.9, p=0.01) and de novo atrial fibrillation at admission (40% vs 0%, p&lt;0.01) were associated with higher 1-year all-cause mortality occurrence and were identified as 2 independent risk predictors by multivariate Cox regression. Kaplan-Meier curves confirmed its significant influence in 1-year survival free of adverse event (Figure). Time among diagnosis and percutaneous treatment (p=0.99), PESI score (p=0.24) and other clinical, haemodynamic and echocardiographic features did not influence mortality and suggest similarity of the PE severity at baseline. Technical characteristics were also not associated with mortality.

Conclusions

Aspiration thrombectomy for acute high- and intermediate-high-risk PE was feasible with a high clinical success rate. One-year all-cause mortality rate was elevated and predicted by high comorbidity index and de novo atrial fibrillation at admission. This data support the national expansion of this new PE treatment, but probably and as similar to other invasive techniques, we need to take into account comorbidities and avoid futility in multimorbidity pts.

Funding Acknowledgement

Type of funding sources: None.

Gut Microbiota as a Potential Player in Mn-Induced Neurotoxicity

Manganese (Mn) is an essential metal, which at high exposures causes neurotoxic effects and neurodegeneration. The neurotoxic effects of Mn are mediated by neuroinflammation, oxidative and endoplasmic reticulum stress, mitochondrial dysfunction, and other mechanisms. Recent findings have demonstrated the potential impact of Mn overexposure on gut microbiota dysbiosis, which is known to contribute to neurodegeneration via secretion of neuroactive and proinflammatory metabolites. Therefore, in this review, we discuss the existing data on the impact of Mn exposure on gut microbiota biodiversity, bacterial metabolite production, and gut wall permeability regulating systemic levels. Recent data have demonstrated that Mn exposure may affect gut microbiota biodiversity by altering the abundance of Shiegella, Ruminococcus, Dorea, Fusicatenibacter, Roseburia, Parabacteroides, Bacteroidetes, Firmicutes, Ruminococcaceae, Streptococcaceae, and other bacterial phyla. A Mn-induced increase in Bacteroidetes abundance and a reduced Firmicutes/Bacteroidetes ratio may increase lipopolysaccharide levels. Moreover, in addition to increased systemic lipopolysaccharide (LPS) levels, Mn is capable of potentiating LPS neurotoxicity. Due to the high metabolic activity of intestinal microflora, Mn-induced perturbations in gut microbiota result in a significant alteration in the gut metabolome that has the potential to at least partially mediate the biological effects of Mn overexposure. At the same time, a recent study demonstrated that healthy microbiome transplantation alleviates Mn-induced neurotoxicity, which is indicative of the significant role of gut microflora in the cascade of Mn-mediated neurotoxicity. High doses of Mn may cause enterocyte toxicity and affect gut wall integrity through disruption of tight junctions. The resulting increase in gut wall permeability further promotes increased translocation of LPS and neuroactive bacterial metabolites to the systemic blood flow, ultimately gaining access to the brain and leading to neuroinflammation and neurotransmitter imbalance. Therefore, the existing data lead us to hypothesize that gut microbiota should be considered as a potential target of Mn toxicity, although more detailed studies are required to characterize the interplay between Mn exposure and the gut, as well as its role in the pathogenesis of neurodegeneration and other diseases.

Evaluating the risk of manganese-induced neurotoxicity of parenteral nutrition: review of the current literature

INTRODUCTION

Several diseases and clinical conditions can affect enteral nutrition and adequate gastrointestinal uptake. In this respect, parenteral nutrition (PN) is necessary for the provision of deficient trace elements. However, some essential elements, such as manganese (Mn) may be toxic to children and adults when parenterally administered in excess, leading to toxic, especially neurotoxic effects.

AREAS COVERED

Here, we briefly provide an overview on Mn, addressing its sources of exposure, the role of Mn in the etiology of neurodegenerative diseases, and focusing on potential mechanisms associated with Mn-induced neurotoxicity. In addition, we discuss the potential consequences of overexposure to Mn inherent to PN.

EXPERT OPINION

In this critical review, we suggest that additional research is required to safely set Mn levels in PN, and that eliminating Mn as an additive should be considered by physicians and nutritionists on a case by case basis in the meantime to avoid the greater risk of neurotoxicity by its presence. There is a need to better define clinical biomarkers for Mn toxicity by PN, as well as identify new effective agents to treat Mn-neurotoxicity. Moreover, we highlight the importance of the development of new guidelines and practice safeguards to protect patients from excessive Mn exposure and neurotoxicity upon PN administration.

Molecular Targets of Manganese-Induced Neurotoxicity: A Five-Year Update

Understanding of the immediate mechanisms of Mn-induced neurotoxicity is rapidly evolving. We seek to provide a summary of recent findings in the field, with an emphasis to clarify existing gaps and future research directions. We provide, here, a brief review of pertinent discoveries related to Mn-induced neurotoxicity research from the last five years. Significant progress was achieved in understanding the role of Mn transporters, such as SLC39A14, SLC39A8, and SLC30A10, in the regulation of systemic and brain manganese handling. Genetic analysis identified multiple metabolic pathways that could be considered as Mn neurotoxicity targets, including oxidative stress, endoplasmic reticulum stress, apoptosis, neuroinflammation, cell signaling pathways, and interference with neurotransmitter metabolism, to name a few. Recent findings have also demonstrated the impact of Mn exposure on transcriptional regulation of these pathways. There is a significant role of autophagy as a protective mechanism against cytotoxic Mn neurotoxicity, yet also a role for Mn to induce autophagic flux itself and autophagic dysfunction under conditions of decreased Mn bioavailability. This ambivalent role may be at the crossroad of mitochondrial dysfunction, endoplasmic reticulum stress, and apoptosis. Yet very recent evidence suggests Mn can have toxic impacts below the no observed adverse effect of Mn-induced mitochondrial dysfunction. The impact of Mn exposure on supramolecular complexes SNARE and NLRP3 inflammasome greatly contributes to Mn-induced synaptic dysfunction and neuroinflammation, respectively. The aforementioned effects might be at least partially mediated by the impact of Mn on α-synuclein accumulation. In addition to Mn-induced synaptic dysfunction, impaired neurotransmission is shown to be mediated by the effects of Mn on neurotransmitter systems and their complex interplay. Although multiple novel mechanisms have been highlighted, additional studies are required to identify the critical targets of Mn-induced neurotoxicity.

Review of the mechanism underlying mefloquine-induced neurotoxicity

Mefloquine, a potent blood schizontocide, is effective against drug-resistant Plasmodium falciparum. This property, along with its unique pharmacokinetic profile, makes mefloquine a widely prescribed antimalarial drug. However, several epidemiological studies have raised concerns on the safety of mefloquine as prophylaxis for malaria. Well-documented side-effects of mefloquine include abnormal dreams, insomnia, anxiety, and depressed mood, as well as nausea and dizziness (the last two most frequent effects). The mechanisms that underlie the neurological/psychiatric complications of mefloquine are poorly understood. The aim of this study was to review the literature on the neurotoxic mechanisms of action of mefloquine to better understand its potential toxicity in the central nervous system, highlighting the mechanisms that lead to its psychiatric disorders. Experimental studies on the neurotoxic effects of mefloquine discussed herein include brain transporters of mefloquine, alteration in neurotransmitters, disruption on calcium (Ca²⁺) homeostasis and neuroinflammation, generation of oxidative stress response in neurons (involving glutathione, increased F2-isoprostanes, accumulation of cytosolic lipid globules), and alteration of voltage-dependent channels, as well as gap junction intercellular communications. Although several hypotheses have been proposed for the mechanisms that mediate mefloquine-induced brain damage, they are not fully understood, necessitating additional studies in the future.

New insights on mechanisms underlying methylmercury-induced and manganese-induced neurotoxicity

Toxic and essential elements are widely distributed in the Earth's crust and individuals may be exposed to several of them. Indeed, exposure to toxic elements such as mercury (Hg) can be a potential health risk factor of health, mainly by ingestion of fish containing methylmercury (MeHg). On the other hand, essential elements such as manganese (Mn) play an important role in physiological process in human body. However, Mn overexposure may cause toxic effects. In this respect, the neurotoxic effects of MeHg and Mn on the developing brain are well recognized. Therefore, in this critical review, we address the effects of MeHg and Mn on cell signaling pathways which may contribute to molecular mechanisms involved in MeHg- and Mn-induced neurotoxicity.

Assessing the neurotoxicity of the carbamate methomyl in Caenorhabditis elegans with a multi-level approach

The neurotoxicity and developmental effects of a widely applied insecticide (methomyl) was investigated by a multi-level approach (behavior and biometry, biochemical alterations and neurodegeneration) in Caenorhabditis elegans upon a short-term exposure (1 h) and a post-exposure period (48 h). The 1-h exposure to sub-lethal concentrations of methomyl (lower than 0.320 g L^-1; i.e. below the estimated LC₁₀) triggered significant changes on motor behavior and development impairment. The type of movement was significantly altered in methomyl-exposed worms, as well as biometric parameters (worms frequently idle and moving more backwards than controls; small body area, length and wavelength). These effects were followed by an increase of acetylcholine levels. Interestingly, after the 48-h recovery period, movement of previously exposed worms was similar to controls, and a concentration-dependent reversion of biometric endpoints was recorded, pointing out the transient action of the carbamate in line with an apparent absence of cholinergic neurons damage. This study provided new insight on the neurotoxicity of methomyl by showing that effects on movement and development were transient, and apparently did not result in neurodegeneration in cholinergic neurons. Moreover, these findings reinforced the advantages of using C. elegans in a multi-level approach for pesticide effects assessment.

Endothelial Dysfunction Induced by Cadmium and Mercury and its Relationship to Hypertension

Hypertension is an important public health concern that affects millions globally, leading to a large number of morbidities and fatalities. The etiology of hypertension is complex and multifactorial, and it involves environmental factors, including heavy metals. Cadmium and mercury are toxic elements commonly found in the environment, contributing to hypertension. We aimed to assess the role of cadmium and mercury-induced endothelial dysfunction in the development of hypertension. A narrative review was carried out through database searches. In this review, we discussed the critical roles of cadmium and mercury in the etiology of hypertension and provided new insights into potential mechanisms of their effect, focusing primarily on endothelial dysfunction. Although the mechanisms by which cadmium and mercury induce hypertension have yet to be completely elucidated, evidence for both implicates impaired nitric oxide signaling in their hypertensive etiology.

An updated systematic review on the association between Cd exposure, blood pressure and hypertension

BACKGROUND

Since the first report by Perry et al. (1955), most studies affirmed the hypertensive effects of cadmium (Cd) in humans. Nonetheless, conclusions between studies remain inconsistent.

OBJECTIVE

The aim of this study was to reevaluate the evidence for a potential relationship between Cd exposure and altered blood pressure and/or hypertension, focusing on studies published between January 2010 and March 2020.

METHODS

We reviewed all observational studies from database searches (PubMed and SCOPUS) on Cd exposure and blood pressure or hypertension. We extracted information from studies that provided sufficient data on population characteristics, smoking status, exposure, outcomes, and design.

RESULTS

Thirty-eight studies met our inclusion criteria; of those, twenty-nine were cross sectional, three case control, five cohort and one interventional study. Blood or urinary Cd levels were the most commonly used biomarkers.

CONCLUSIONS

A positive association between blood Cd levels and blood pressure and/or hypertension was identified in numerous studies at different settings. Limited number of representative population-based studies of never-smokers was observed, which may have confounded our conclusions. The association between urinary Cd and blood pressure and/or hypertension remains uncertain due to conflicting results, including inverse relationships with lack of strong mechanistic support. We point to the urgent need for additional longitudinal studies to confirm our findings.

Manganese in the Diet: Bioaccessibility, Adequate Intake, and Neurotoxicological Effects

Manganese (Mn) is an essential element that participates in several biological processes. Mn serves as a cofactor for several enzymes, such as glutamine synthetase and oxidoreductases, that have an important role in the defense of the organisms against oxidative stress. The diet is the main source of Mn intake for humans, and adequate daily intake levels for this metal change with age. Moreover, in higher amounts, Mn may be toxic, mainly to the brain. Here, we provide an overview of Mn occurrence in food, addressing its bioaccessibility and discussing the dietary standard and recommended intake of Mn consumption. In addition, we review some mechanisms underlying Mn-induced neurotoxicity.

Manganese-induced neurodegenerative diseases and possible therapeutic approaches

INTRODUCTION

Neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis and prion disease represent important public health concerns. Exposure to high levels of  heavy metals such as manganese (Mn) may contribute to their development.

AREAS COVERED

In this critical review, we address the role of Mn in the etiology of neurodegenerative diseases and discuss emerging treatments of Mn overload, such as chelation therapy. In addition, we discuss natural and synthetic compounds under development as prospective therapeutics. Moreover, bioinformatic approaches to identify new potential targets and therapeutic substances to reverse the neurodegenerative diseases are discussed.

EXPERT OPINION

Here, the authors highlight the importance of better understanding the molecular mechanisms of toxicity associated with neurodegenerative diseases, and the role of Mn in these diseases. Additional emphasis should be directed to the discovery of new agents to treat Mn-induced diseases, since present day chelator therapies have limited bioavailability. Furthermore, the authors encourage the scientific community to develop research using libraries of compounds to screen those compounds that show efficacy in regulating brain Mn levels. In addition, bioinformatics may provide novel insight for pathways and clinical treatments associated with Mn-induced neurodegeneration, leading to a new direction in Mn toxicological research.

Haloperidol Interactions with the dop-3 Receptor in Caenorhabditis elegans

Haloperidol is a typical antipsychotic drug commonly used to treat a broad range of psychiatric disorders related to dysregulations in the neurotransmitter dopamine (DA). DA modulates important physiologic functions and perturbations in Caenorhabditis elegans (C. elegans) and, its signaling have been associated with alterations in behavioral, molecular, and morphologic properties in C. elegans. Here, we evaluated the possible involvement of dopaminergic receptors in the onset of these alterations followed by haloperidol exposure. Haloperidol increased lifespan and decreased locomotor behavior (basal slowing response, BSR, and locomotion speed via forward speed) of the worms. Moreover, locomotion speed recovered to basal conditions upon haloperidol withdrawal. Haloperidol also decreased DA levels, but it did not alter neither dop-1, dop-2, and dop-3 gene expression, nor CEP dopaminergic neurons' morphology. These effects are likely due to haloperidol's antagonism of the D2-type DA receptor, dop-3. Furthermore, this antagonism appears to affect mechanistic pathways involved in the modulation and signaling of neurotransmitters such as octopamine, acetylcholine, and GABA, which may underlie at least in part haloperidol's effects. These pathways are conserved in vertebrates and have been implicated in a range of disorders. Our novel findings demonstrate that the dop-3 receptor plays an important role in the effects of haloperidol.

Blood cadmium levels and sources of exposure in an adult urban population in southern Brazil

BACKGROUND

Cadmium (Cd) is a toxic metal that is widely present in the environment due to geologic and anthropogenic sources. Exposures to high Cd levels may cause nephrotoxicity, carcinogenicity, pulmonary and cardiovascular disease, among others. The goal of this study was to investigate in an adult urban population whether an association exists between sources and levels of Cd exposure and blood Cd concentrations.

METHODS

Using a census-based design, a total of 959 adults, aged 40 years or older, were randomly selected. Information on socio-demographics, dietary, and lifestyle background was obtained by household interviews. Blood Cd levels were measured by inductively coupled-plasma mass spectrometry. Geometric means (GM) (95% CI) and the 50th percentile were determined, stratified by sex, age, race, education, income class, smoking status, consumption of vegetables, red meat and milk, occupation and blood pressure. To assess the association between Cd exposure and the aforementioned variables, we estimated the geometric mean ratio (GMR) (95%CI) of blood Cd concentrations.

RESULTS AND CONCLUSION

The geometric mean (95%CI) of blood Cd levels in the total population was 0.25 (0.22, 0.27) ug/dL. In a univariate analysis, significantly higher blood Cd levels were found in men (p < 0.001), current and former smokers (p < 0.001), alcohol drinkers (p < 0.001), those who never or almost never consumed milk (p < 0.001), and in subjects with higher diastolic blood pressure (p = 0.03). Significant correlations were found between the number of cigarettes consumed daily and blood Cd levels. Multivariate analysis confirmed higher blood Cd concentrations were associated with alcohol consumption (GMR 95%CI = 1.28, 1.04-1.59) and in former and current smokers (GMR 95% IC = 1.33, 1.06-1.67 and 4.23, 3.24-5.52, respectively). Our results shed novel information on variables associated with blood Cd levels in an urban Brazilian population, and should encourage additional research to prevent environmental Cd exposure, both in Brazil and globally.

New perspectives for physiotherapy education concerning assistive technology solutions as valid options to enhance functioning and quality of life

Introduction Recognizing that AT service characteristics, including knowledge and reasoning of providers, play a potential role in the appropriated selection and training, with impact on the psychosocial domains of QoL. In Portugal, AT services are detected to be ineffective concerning evaluation, recommendation, advocacy, training and outcome measuring, what could be a reason for these findings.

Objectives To investigate the relationship between AT services characteristics and psychosocial impact of the wheelchairs on users QoL to get insights to new approach models in physiotherapy.

Methodology Procedures included answering to self-administered questionnaires at their own. The dependent variable was the psychosocial impact of assistive devices (PIADS) and the independent variables were satisfaction with AT (QUEST) and AT service characteristics.

Results Participants were 184 wheelchair users for more than one year with diverse diagnosis; age M = 37.3 years, recruited at physiotherapy/rehabilitation settings in Portugal. Wheelchair users are more satisfied with devices than with AT services. Correlations between psychosocial impact of wheelchair are moderate regarding the satisfaction of device dimension, measured by QUEST. No corrections were found to satisfaction with service dimension Manual wheelchair users scored lower psychosocial impact than motorized wheelchair users and that difference was statistically significant.

Conclusion PT should be aware of the newest high technology devices introduced on the market, payment sources and state AT programs as well as destigmatize dependence associated to AT. We got significant insights to AT field and to the development of PT curriculum; PT students need more than the basic level of knowledge and training they achieved at school to feel prepared to provide AT services. After graduation, PTs need continuing education on AT. Strategies are discussed on this report.

Wearable Sensor-Based Exercise Biofeedback for Supporting Fall Prevention at Physiotherapy

Introduction Exercise interventions focused on strength and balance are effective for falls prevention in older people. Several fall prevention programs were developed with this intent, however there is often a lack of personalization in these solutions. Technological interventions namely biofeedback systems have been shown recently to have the ability to objectively assess therapeutic exercise in real time to improve quality performance.

Objectives To describe a technological solution with biofeedback system to be used by physiotherapists at the clinic, to assist the learning process of a personalized and progressive strength and balance exercise program.

Methodology The exercises are monitored by two wearable inertial sensors and a pressure platform for mobility, strength and balance measurements. In order to validate the system, a set of five exercises, from the Otago Exercise Program, were tested with a group of 16 older adults during several sessions. Spatial, temporal and balance metrics were extracted during the exercises, providing quantitative biofeedback during the exercise.

Results Inertial and pressure sensors are suitable for exercise tracking during fall prevention exercises. Range of motion, weight distribution and shifting, balance and cycle identification were successfully monitored for all exercises. This system successfully automated the process of creating individualized and personalized exercise biofeedback systems to fall prevention programs.

Conclusion This study demonstrates this technological solution holds promise in falls prevention. FallSensing Clinic is a feasible monitor and biofeedback tool that can be applied to clinical practice allowing people to better perform the exercise program.

Effect of wearable sensor-based Otago Exercise Program biofeedback in older adults with moderate to high risk of falling

Introduction Falls remain a major public health issue. The ageing process is characterized by a progressive decrease in muscle strength, reaction time, postural control and changes in sensory systems. Wearable sensor-based biofeedback systems used in physiotherapy, particularly incorporated in exercise programs, are promising strategies to enhance the learning of strength and balance exercises and improve self-efficacy.

Objectives To evaluate the effect of the wearable sensor-based Otago Exercise Program (OTAGO) biofeedback in older adults with moderate to high risk.

Methodology Sixty participants (84.35 years) were distributed to the experimental group (26) and a control group (34). The EG underwent the OTAGO incorporated in a technological system using pressure and inertial sensors and biofeedback in real-time, administered by a physiotherapist for 5 weeks, with a frequency of 2 times a week. The CG kept doing their regular activities. Outcome measures included handgrip strength (HG), Time Up and Go (TUG), 30 seconds Sit to Stand, 10 meters Walking Speed (10m WS), 4 Stage Balance Test “Modified”, Step test and Questionnaire of Self-efficacy for exercise.

Results At baseline, significant differences were observed regarding the 10m WS (p &lt; 0.001), TUG (p = 0.036) and HG (p = 0.001). Relatively to 4SBTM, in post-intervention was seen significant difference (p = 0.008) and in EG there was also substantial results (p &lt; 0.001). The same happens in SEE (p = 0.013 and p = 0.020, respectively). A significant increase was found in EG so that the post-intervention 10m WS was statistically higher compared with the CG (EG: 0.42±0.29; CG: 1.10±0.51; p = 0.003). In the CG worst results were observed in some of the functional tests.

Conclusion Biofeedback in real-time facilitates the self-learning of the exercise program, and it is a useful tool for training strength, balance and self-efficacy for exercise, contributing to reducing the risk of falls.

Exergaming as a tool to enhance strength, balance, gait, mobility, participation, self-efficacy for exercise and adherence in older adults

Introduction It is projected that the number of adults aged 60 or above will be 1.4 billion in 2030 and 2.1 billion in 2050. With aging, mobility limitations can cause severe difficulties on being independent during activities of daily living. Exercise has been shown as effective to counteract the impact of aging, although it is hard to create adherence. Exergames, as they increase the appeal of exercise, show promising results in terms of participation and promotion of healthy behaviours.

Objectives This study aimed at assessing the effectiveness of the Otago Exercise Program incorporated in FallSensing Exergames.

Methodology Community-dwelling older adults aged 60 or over, were recruited from facilities in Coimbra, Portugal and randomized in two groups, 27 allocated to the intervention (IG) and 34 to the control (CG). Regular activities of daily living (CG) were compared to an Exergame program (IG). Assessments were made at baseline and re-assessments at 8 weeks/16 sessions, regarding strength, balance, walking speed, participation and self-efficacy for exercise.

Results 61 older adults (77% female), mean ages were 82.22 (IG) and 87.26 (CG) years. After 8 weeks, CG demonstrated a decrease in functional ability. IG got improvement in Step test (p = 0.001), 4 Stage Balance Modified test (p = 0.001), Self-Efficacy for Exercise (p = 0.009) and Activities and Participation Profile Related to Mobility (p &lt; 0.001) questionnaires.

Conclusion Exergaming was safe and effective in improving functional ability, participation and self-efficacy. Nevertheless, some considerations are necessary when prescribing an Exergames, mainly concerning frequency and intensity of the exercise program and participants’ age.

Avaliação da Resistência de União de Pinos de Fibra de Vidro à Dentina Radicular Utilizando Diferentes Cimentos e Compósitos Preaquecidos

Este estudo avaliou a resistência de união (RU) de pinos de fibra de vidro (PFV) à dentina radicular utilizando cimentos resinosos convencional e autoadesivo, e compósitos preaquecidos a 68 °C. Quarenta dentes bovinos foram distribuídos em quatro grupos (n10), de acordo com o agente cimentante utilizado: G1 – RelyX ARC G2 – RelyX U200 G3 – Filtek Z100 preaquecido e G4 – Filtek Bulkfill preaquecido. Os PFVs foram condicionados com H2O2 24%/1min e em seguida silanizados. Em G1, G3 e G4, os canais foram condicionados com H3PO4 37%/15s, lavados por 30s e secos com sucção a vácuo/5s e um cone de papel absorvente. Posteriormente, foi aplicado um adesivo quimicamente ativado. Em G2, os canais foram apenas lavados e secos conforme descrito anteriormente. Os agentes cimentantes foram introduzidos no interior do canal com seringa Centrix, os pinos foram inseridos e o conjunto fotoativado (1050mW/cm²/40s). Os espécimes foram seccionados e submetidos ao teste de push-out em máquina universal de ensaios. O padrão de falha ocorrido foi observado com estereomicroscópio. Os dados obtidos foram submetidos à ANOVA de dois fatores e teste de Tukey para contraste entre as médias (5%). Os valores da RU foram estatisticamente semelhantes entre os grupos. Em relação aos terços radiculares, os valores foram maiores no terço cervical que nos terços médio e apical, os quais foram semelhantes entre si. As falhas adesivas entre o agente cimentante e a dentina predominaram. Nestes termos, concluiu-se que os compósitos preaquecidos podem ser agentes cimentantes alternativos para a fixação de PFVs.Palavras-chave: Resistência de União. Pino de Fibra de Vidro. Resina Composta.

Avaliação de Retentores Intrarradiculares Confeccionados em Compósito Restaurador: Estudo Piloto

Este estudo objetivou avaliar a resistência à fratura (RF) de dentes tratados endodonticamente e restaurados com retentores intrarradiculares (RIR) cimentados em distintas profundidades. As coroas de 18 dentes humanos (CEO: 850846) unirradiculares foram seccionadas e, após o preparo das raízes para receberem os RIR, estas foram divididas, aleatoriamente, em 6 grupos (n3), de acordo com o tipo de RIR e a profundidade do preparo do canal: Grupo PFV10 – Pino de fibra de vidro (PFV) / 10mm Grupo PFV5 – PFV / 5mm Grupo PC10 – Pino de compósito (PC) / 10mm Grupo PC5 – PC / 5mm Grupo CC5 – Compósito Compactado (CC) / 5mm Grupo CC2 – CC / 2mm. Os PFV foram condicionados com H2O2 24% / 1min e silnaizadas. Após o embutimento das raízes, a dentina radicular foi hibridizada e um cimento resinoso dual empregado para fixação dos PFV e dos PC. Nos grupos CC5 e CC2, o compósito foi inserido no conduto em incrementos de 2,0mm³ e fotoativado (1050mW/cm2/40s). Após o teste de compressão a 135 °C para análise da RF, os espécimes foram levados à máquina de ensaios (1,0mm/min) e os dados colhidos foram submetidos à ANOVA (a5%). Verificou-se que a RF dos espécimes não foi influenciada pelo tipo de RIR empregado. Nos grupos PFV, o padrão de falha predominante foi adesiva entre o núcleo e a raiz nos demais predominaram as fraturas da cervical radicular. Dentro das limitações deste estudo, pode-se concluir que, embora a resistência à fratura não tenha sido influenciada pelos grupos testados, o tipo de falha verificado foi desfavorável para os pinos de compósito.Palavras-chave: Retentor Intrarradicular. Pinos de Fibra. Compósito.

Evolution of Socioeconomic Conditions and Its Relation to Spatial-Temporal Changes of Giardiasis and Helminthiasis in Amazonian Children

This study analyzed the evolution of socioeconomic, sanitary, and personal factors as well as spatiotemporal changes in the prevalence of helminthiasis and giardiasis in urban Amazonian children between 2003 and 2011. Child age, lack of sanitation, and lack of access to bottled water were identified as significant associated factors for helminthiasis and giardiasis. There was an overall improvement in socioeconomic and sanitary conditions in the city resulting in decreased helminth prevalences from 12.42 to 9.63% between 2003 and 2010, but the prevalence increased to 15.03% in 2011 due to migratory movement and unstable sanitary conditions. As for Giardiasis, socioeconomic and environmental changes were not enough to reduce prevalence (16% in 2003 and 23% in 2011). Spatial analysis identified a significant cluster for helminthiasis in an area of poor housing conditions. Control programs in the Amazon need to target high-risk areas focusing changes in sanitation, water usage, and health education.

Comparative study of the in situ immune response in oral and nasal mucosal leishmaniasis

Mucosal Leishmaniasis (ML) may occur in both nasal and oral mucosa. However, despite the impressive tissue destruction, little is known about the oral involvement. To compare some changes underlying inflammation in oral and nasal ML, we performed immunohistochemistry on mucosal tissue of 20 patients with ML (nasal [n = 12]; oral [n = 8] lesions) and 20 healthy donors using antibodies that recognize inflammatory markers (CD3, CD4, CD8, CD22, CD68, neutrophil elastase, CD1a, CLA, Ki67, Bcl-2, NOS2, CD62E, Fas and FasL). A significantly larger number of cells, mainly T cells and macrophages, were observed in lesions than in healthy tissue. In addition, high nitric oxide synthase 2 (NOS2) expression was associated with a reduced detection of parasites, highlighting the importance of NOS2 for parasite elimination. Oral lesions had higher numbers of neutrophils, parasites, proliferating cells and NOS2 than nasal lesions. These findings, together with the shorter duration of oral lesions and more intense symptoms, suggest a more recent inflammatory process. It could be explained by lesion-induced oral cavity changes that lead to eating difficulties and social stigma. In addition, the frequent poor tooth conservation and gingival inflammation tend to amplify tissue destruction and symptoms and may impair and confuse the correct diagnosis, thus delaying the onset of specific treatment.

Effects of decrease of extracellular sodium in carbachol-evoked catecholamine secretion in isolated adrenal medullae of rats

The effect of extracellular Na(+) deprivation on the carbachol-evoked catecholamine secretion was evaluated in chromaffin cells. Isolated adrenal medullae of male Wistar rats were incubated in solutions with different sodium concentrations (144,0; 75,0; 25,0 and psi mM). Catecholamine secretions inversely increased as a response to fall of extracellular concentration of sodium. The magnitude of response to cholinergic stimulus (carbachol 100 microM) was decreased in low extracellular sodium concentration. Atropine (100 microM) inhibited secretion of catecholamine induced by carbachol in the presence and in the absence of extracellular sodium. Results suggest that in isolated adrenal medullae of rats (1) decrease in concentration of extracellular sodium increases secretion of catecholamines, perhaps by a greater influx of calcium from the extracellular environment through reversal of Na(+) /Ca(2+) exchanger; (2) intensity of catecholamine secretion induced by cholinergic stimulus seems to depend on extracellular sodium.

Safety and efficacy of sildenafil in postmenopausal women with sexual dysfunction

OBJECTIVES

Sildenafil has been demonstrated to be safe and effective in the treatment of men with erectile dysfunction. The role of sildenafil in treating women with sexual dysfunction has heretofore not been reported. The purpose of this preliminary study was to ascertain the response of postmenopausal women with self-described sexual dysfunction treated with sildenafil for 3 months.

METHODS

Thirty-three consecutive postmenopausal women with sexual dysfunction based on history were entered in this open-label, nonrandomized study. All patients received 50 mg of sildenafil. Efficacy was assessed at weeks 4, 8, and 12 using a newly developed 9-item, self-administered Index of Female Sexual Function (IFSF) and a global efficacy question ([GEQ] Did treatment improve your sexual function?). The IFSF quantifies the domains of desire, quality of sexual intercourse, overall satisfaction with sexual function, orgasm, lubrication, and clitoral sensation.

RESULTS

Of the group, 30 women (91 %) completed the study and were available for follow-up at 3 months. Mean baseline IFSF score before therapy was 24.8+/-9.8. Mean usage of sildenafil was 3.1+/-1.4 times per week for the duration of the study. The IFSF score improved to 29.5+/-7.6, 30.3+/-8.5, and 31.4+/-10.4 at 4, 8, and 12 weeks, respectively (P = 0.25). Mean scores for questions 2 (lubrication), 8 (orgasm), and 9 (clitoral sensation) improved by 23.2%, 7.4%, and 31.3%, respectively, at 12 weeks. Seven women (21%) noted improvement on the GEQ. Overall, only 6 (18.1%) of 33 patients had a significant (more than 60% improvement in IFSF score) therapeutic response. Clitoral discomfort and "hypersensitivity" occurred in 7 women (21%), 3 of whom withdrew from the study. Other side effects, which did not result in withdrawal from the study, included headache (n = 5), dizziness (n = 4) and dyspepsia (n = 3).

CONCLUSIONS

The data suggest that sildenafil is well tolerated in postmenopausal women with sexual dysfunction. Overall sexual function did not improve significantly, although there were changes in vaginal lubrication and clitoral sensitivity. The role of sildenafil in treating sexual dysfunction in various cohorts of women remains to be determined.

Intermittent alpha-blocker therapy in the treatment of men with lower urinary tract symptoms

OBJECTIVES

To determine the safety and efficacy of intermittent alpha-blocker therapy in men with lower urinary tract symptoms (LUTS) in a prospective study. Alpha-blockers have been demonstrated to be safe and effective in the treatment of men with LUTS. To date, the role of varying dosing regimens in responding patients has not been well studied.

METHODS

Men with LUTS were entered into this prospective open label, parallel, randomized trial. In phase 1, patients were treated with alfuzosin, 2.5 mg three times daily for 3 months. In phase 2, those patients who had a significant therapeutic response were randomized into one of the following three groups: (1) maintenance of alfuzosin; (2) alfuzosin every other day; and (3) discontinuation of alfuzosin (ie, no treatment). Patients were followed up for a total of 6 months. Parameters of evaluation included the International Prostate Symptom Score (IPSS), global satisfaction, peak urinary flow rate (Qmax), and adverse events.

RESULTS

At 3 months, there were 79 patients who were categorized as having obtained a therapeutic response: IPSS decreased to 7.6 +/- 3.2 and Qmax increased to 11.3 +/- 2.9 mL/s. After randomization, IPSS was 7.1 +/- 2.9 and 6.5 +/- 2.5 for group 1; 6.5 +/- 3.2 and 6.7 +/- 2.1 for group 2; and 11.4 +/- 4.8 and 12.3 +/- 4.9 for group 3 at 3 and 6 months, respectively. Qmax was 12.7 +/- 4.8 and 11.7 +/- 5.2 mL/s for group 1; 12.2 +/- 3.9 and 11.9 +/- 3.7 mL/s for group 2; and 9.7 +/- 2.5 and 9.3 +/- 2.1 mL/s for group 3 at 3 and 6 months, respectively. Global satisfaction at 6 months was the same for groups 1 and 2. There were no differences in adverse events among the three groups.

CONCLUSIONS

In men with LUTS who responded to alfuzosin, changing the dosing regimen from daily to once every other day resulted in similar efficacy and safety at 3 and 6 months. By contrast, complete cessation of alfuzosin resulted in recurrence of both symptoms and impaired urinary flow. These data provide evidence that in responding patients, intermittent alpha-blocker therapy may be a reasonable therapeutic regimen. The role of intermittent alpha-blocker therapy using other agents, as well as in a large cohort of men with LUTS, remains to be determined.

[Cutaneous vesicostomy in children]

OBJECTIVE

In this report we assessed the results obtained with cutaneous vesicostomy for the temporary diversion of urine in small children.

PATIENTS AND METHODS

We analyzed the medical records of 20 patients (17 boys and 3 girls) that underwent this type of diversion at our institution. Cutaneous vesicostomy was done due to severe hydronephrosis with low renal function and/or urinary tract infection with metabolic acidosis.

RESULTS

The urinary tract anomalies were posterior urethral valves in 12 children, vesicoureteral reflux in 7 and anterior urethral valve in one. Elevated levels of serum urea and creatinine were found in 16 patients during pre-operative evaluation. During the follow-up there was a reduction of hydronephrosis in all patients, and 5 progressed to chronic renal failure. These patients had worse development of weight and body lenght when compared to those with normal renal function. The post-operative complications were prolapse in 2 patients and stenosis of the stoma in 2.

CONCLUSION

cutaneous vesicostomy has proved to be an useful form of urinary diversion. In our experience it is an effective and easily reversible temporary treatment for infants and children with severe hydronephrosis associated with urinary tract infection due to infravesical obstruction or vesicoureteral reflux.

[Placenta: a barrier for renotrophic factor?]

BACKGROUND

To evaluate if the renotrophic factor can pass through the placenta and act on the fetal kidney.

MATERIAL AND METHODS

Twenty pregnant rats were divided into 4 groups of 5 animals: 1-control; 2-sham operated animals; 3-right nephfrectomy; 4-right nephrectomy--left polar nephrectomy. All rats were operated on during the 14 or 15 day of pregnancy. Maternal weight, serum urea and creatinine, number of fetal rats, fetal body and renal weight; DNA, RNA, protein and the amount of water in fetal kidneys were evaluated.

RESULTS

Fetal kidneys showed a fall in weight in groups 3 and 4. In these groups tissue water concentration was lesser than groups 1 and 2. Fetal kidneys amounts of DNA, RNA and protein were similar in all groups.

CONCLUSIONS

This study suggest that renotrophin could be a multifactorial system that can cross the placenta. The fall in renal fetal weight following maternal nephrectomy was consequent to a lesser tissue water content. Hypoplasia or hypotrophy did not play a role in this event. However, the fall in fetal kidney water was independent of the amount of maternal renal tissue that was removed.

Program design for adult learners

The voice of adult learners is often overlooked in the design of programs that are specifically constructed to meet their learning needs. This article portrays the design of a midwifery re-registration program that commenced with a survey of non-practising midwives. The organisation of the course, together with the processes involved in curriculum building are explained. The adult learner, particularly in a situation where previous knowledge, skills and experience are vital inputs to the design of programs, have been highlighted.

Antibody titers to Toxoplasma gondii in renal transplant patients

Of 70 renal transplant patients submitted to the indirect immunofluorescence reaction test for toxoplasmosis, 16 (23%) had titers higher than 1/4,000, as compared to 0/41 for chronic hemodialysis patients and 0/50 for blood donors. The indirect immunofluorescence reaction titers in the renal transplant patients correlated with time since initiation of immunosuppressive therapy. Six percent (2/33) of the patients had been on immunosuppressors for less than one year, 30.7% (4/13) for 1 to 2 years, and 41.6% (10/24) for 2 or more years. The frequency of negative titers among the immunosuppressed patients was similar to that observed for blood donors and chronic hemodialysis patients. Fifty percent (8/16) of the patients with higher immunofluorescence reaction titers also had significantly high (greater than or equal to 320) positive titers in the complement fixation test. The results indicate that: 1) the immunosuppressive scheme used for the transplant patients may favor the reactivation of infection from latent Toxoplasma gondii foci, and 2) even though the patients were immunosuppressed, their antitoxoplasma antibody levels were high enough to be detected by the serologic test.

The Doppler flowmeter as an aid in the diagnosis of the hyperstomy syndrome

A new aid in the diagnosis of the hyperstomy syndrome by non-invasive procedure using the Doppler flowmeter is presented. Several studies prove that there is an increased venous saturation and increased venous pressure in the hyperstomy syndrome, i.e., various degrees of arterialization of the venous system as well as an increase in the venous flow. Based on these studies the authors detected changes of this flow with the Doppler flowmeter interpreted as being the results of the activation of arteriolo-venular communications. In addition, in the first ten cases in which these have been found, serial arteriography confirmed the diagnosis of hyperstomy syndrome.

[Influence of the cryopreservation at nitrogen temperature on the vaccinic ability of the "PF" strain of Trypanosoma cruzi (author's transl)]

The cryopeservation of the "PF" strain of T. cruzi at -196 degree C has not changed its effectiveness in protecting mice against a posterior infection with a virulent Trypanosoma cruzi strain. The cryopeservation technique utilized seems to be efficient and of practical and rapid examination.