scholarly journals Evidence Implicating Non-Dioxin-Like Congeners as the Key Mediators of Polychlorinated Biphenyl (PCB) Developmental Neurotoxicity

2020 ◽  
Vol 21 (3) ◽  
pp. 1013 ◽  
Author(s):  
Carolyn Klocke ◽  
Pamela J. Lein
Keyword(s):  
Animal Studies ◽  
Polychlorinated Biphenyl ◽  
Significant Proportion ◽  
Significant Risk ◽  
Epidemiological Studies ◽  
Experimental Models ◽  
Developmental Neurotoxicity ◽  
Relative Role ◽  
Neurodevelopmental Outcomes ◽  
Critical Data

Despite being banned from production for decades, polychlorinated biphenyls (PCBs) continue to pose a significant risk to human health. This is due to not only the continued release of legacy PCBs from PCB-containing equipment and materials manufactured prior to the ban on PCB production, but also the inadvertent production of PCBs as byproducts of contemporary pigment and dye production. Evidence from human and animal studies clearly identifies developmental neurotoxicity as a primary endpoint of concern associated with PCB exposures. However, the relative role(s) of specific PCB congeners in mediating the adverse effects of PCBs on the developing nervous system, and the mechanism(s) by which PCBs disrupt typical neurodevelopment remain outstanding questions. New questions are also emerging regarding the potential developmental neurotoxicity of lower chlorinated PCBs that were not present in the legacy commercial PCB mixtures, but constitute a significant proportion of contemporary human PCB exposures. Here, we review behavioral and mechanistic data obtained from experimental models as well as recent epidemiological studies that suggest the non-dioxin-like (NDL) PCBs are primarily responsible for the developmental neurotoxicity associated with PCBs. We also discuss emerging data demonstrating the potential for non-legacy, lower chlorinated PCBs to cause adverse neurodevelopmental outcomes. Molecular targets, the relevance of PCB interactions with these targets to neurodevelopmental disorders, and critical data gaps are addressed as well.

Prenatal exposure to persistent organic pollutants as a risk factor of offspring metabolic syndrome development during childhood

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Marlene Cervantes González
Keyword(s):  
Metabolic Syndrome ◽  
Organic Pollutants ◽  
Prenatal Exposure ◽  
Persistent Organic Pollutants ◽  
Animal Studies ◽  
Polychlorinated Biphenyl ◽  
Environmental Pollutants ◽  
Epidemiological Studies ◽  
Experimental Findings

Abstract Persistent Organic Pollutants (POPs) are exogenous, artificially made chemicals that can disrupt the biological system of individuals and animals. POPs encompass a variety of chemicals including, dioxins, organochlorines (OCs), polychlorinated biphenyl (PCBs), and perfluoroalkyl substances (PFASs) that contain a long half-life and highly resistant to biodegradation. These environmental pollutants accumulate over time in adipose tissues of living organisms and alter various insulin function-related genes. Childhood Metabolic Syndrome (MetS) consists of multiple cardiovascular risk factors, insulin function being one of them. Over the years, the incidence of the syndrome has increased dramatically. It is imperative to explore the role of persistent organic pollutants in the development of Childhood Metabolic Syndrome. Some epidemiological studies have reported an association between prenatal exposure to POPs and offspring MetS development throughout childhood. These findings have been replicated in animal studies in which these pollutants exercise negative health outcomes such as obesity and increased waist circumference. This review discusses the role of prenatal exposure to POPs among offspring who develop MetS in childhood, the latest research on the MetS concept, epidemiological and experimental findings on MetS, and the POPs modes of action. This literature review identified consistent research results on this topic. Even though the studies in this review had many strengths, one major weakness was the usage of different combinations of MetS criteria to measure the outcomes. These findings elucidate the urgent need to solidify the pediatric MetS definition. An accurate definition will permit scientists to measure the MetS as a health outcome properly and allow clinicians to diagnose pediatric MetS and provide individualized treatment appropriately.

Hearing and Neurodevelopmental Outcomes of Young Infants with Parechovirus-A and Enterovirus Meningitis: Cohort Study in Singapore Children and Literature Review

2020 ◽  
Author(s):  
Elis Yuexian Lee ◽  
Jessica Hui Yin Tan ◽  
Chew Thye Choong ◽  
Nancy Wen Sim Tee ◽  
Chia Yin Chong ◽  
...  
Keyword(s):  
Developmental Delay ◽  
Oropharyngeal Dysphagia ◽  
Significant Risk ◽  
Developmental Outcomes ◽  
Autism Spectrum ◽  
Clinical Findings ◽  
Cortical Blindness ◽  
Speech Delay ◽  
Neurodevelopmental Outcomes ◽  
Young Infants

Abstract Parechovirus-A (PeV-A) and Enterovirus (EV) commonly cause childhood aseptic meningitis. Bacterial meningitis in children has been associated with devastating long-term sequelae. However, developmental outcomes are unclear in Parechovirus meningitis. This study aims to review the clinical findings and developmental outcomes of infants with PeV-A and EV meningitis. We performed a retrospective study of infants aged 90 days or younger being admitted to our hospital with PeV-A meningitis between November 2015 and July 2017, with positive cerebrospinal fluid (CSF) PeV-A PCR and negative blood and CSF bacterial cultures. Hearing and neurodevelopmental outcomes were compared with a previous cohort of infants aged 90 days or younger with EV meningitis admitted from January 2015 to December 2015. A total of 161 infants were included in our study, of which 68 infants (42.2%) had PeV-A meningitis and 93 infants (57.8%) had EV meningitis. We assessed their developmental outcome at 6 months, 1 year, and 2 years post-meningitis. At 2 years post-meningitis, three infants with PeV-A meningitis had developmental delay (5.5%), whereas none with EV meningitis had developmental delay. One patient had speech delay and autism spectrum disorder, while two had mild speech delay. When compared with our cohort of EV meningitis ≤90 days old, children with PeV-A meningitis ≤90 days old were more likely to have developmental delay 2 years post-meningitis (odds ratio 2.4, 95% confidence interval 2.0–3.0, p = 0.043). None of the patients with PeV-A or EV meningitis had sensorineural hearing loss or neurological sequelae, such as cortical blindness, oropharyngeal dysphagia, hydrocephalus, epilepsy, or cerebral palsy. Infants with PeV-A meningitis had a significant risk of developmental delay 2 years post-meningitis compared with those with EV meningitis. It is important to follow-up the developmental milestones of infants diagnosed with PeV-A meningitis for at least 2 years; and when they develop developmental delay, to ensure that they receive appropriate intervention.

scholarly journals High susceptibility to varicella among urban and rural pregnant women in South India: a brief report

2021 ◽  
Vol 149 ◽  
Author(s):  
Leeberk Raja Inbaraj ◽  
Sindhulina Chandrasingh ◽  
Nalini Arun Kumar ◽  
Jothi Suchitra ◽  
Abi Manesh
Keyword(s):  
Pregnant Women ◽  
South India ◽  
Significant Proportion ◽  
Prevalence Ratio ◽  
Epidemiological Studies ◽  
Lethal Outcome ◽  
Factors Associated ◽  
Rural And Urban ◽  
History Of ◽  
Secondary Hospital

Abstract Varicella infection during pregnancy has serious and/or difficult implications and in some cases lethal outcome. Though epidemiological studies in developing countries reveal that a significant proportion of patients may remain susceptible during pregnancy, such an estimate of susceptible women is not known in India. We designed this study to study the prevalence and factors associated with susceptibility to varicella among rural and urban pregnant women in South India. We prospectively recruited 430 pregnant women and analysed their serum varicella IgG antibodies as surrogates for protection. We estimated seroprevalence, the validity of self-reported history of chickenpox and factors associated with varicella susceptibility. We found 23 (95% CI 19.1–27.3) of women were susceptible. Nearly a quarter (22.2%) of the susceptible women had a history of exposure to chickenpox anytime in the past or during the current pregnancy. Self-reported history of varicella had a positive predictive value of 82.4%. Negative history of chickenpox (adjusted prevalence ratio (PR) 1.85, 95% CI 1.15–3.0) and receiving antenatal care from a rural secondary hospital (adjusted PR 4.08, 95% CI 2.1–7.65) were significantly associated with susceptibility. We conclude that high varicella susceptibility rates during pregnancy were noted and self-reported history of varicella may not be a reliable surrogate for protection.

scholarly journals Antidiabetic Properties of Naringenin: A Citrus Fruit Polyphenol

Biomolecules ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 99 ◽  
Author(s):  
Danja J. Den Hartogh ◽  
Evangelia Tsiani
Keyword(s):  
Insulin Resistance ◽  
Animal Studies ◽  
Citrus Fruit ◽  
Epidemiological Studies ◽  
Personal Health ◽  
Current Review ◽  
Vegetables And Fruits

Type 2 diabetes mellitus (T2DM) is a metabolic disease characterized by insulin resistance and hyperglycemia and is associated with personal health and global economic burdens. Current strategies/approaches of insulin resistance and T2DM prevention and treatment are lacking in efficacy resulting in the need for new preventative and targeted therapies. In recent years, epidemiological studies have suggested that diets rich in vegetables and fruits are associated with health benefits including protection against insulin resistance and T2DM. Naringenin, a citrus flavanone, has been reported to have antioxidant, anti-inflammatory, hepatoprotective, nephroprotective, immunomodulatory and antidiabetic properties. The current review summarizes the existing in vitro and in vivo animal studies examining the anti-diabetic effects of naringenin.

scholarly journals Treatment-resistant schizophrenia characterised by dopamine supersensitivity psychosis and efficacy of asenapine

2021 ◽  
Vol 14 (4) ◽  
pp. e242495
Author(s):  
Nagara Takao ◽  
Toshiya Murai ◽  
Hironobu Fujiwara
Keyword(s):  
Animal Studies ◽  
Significant Proportion ◽  
Antipsychotic Treatment ◽  
High Dose ◽  
Receptor Density ◽  
Treatment Resistant ◽  
Psychomotor Activity ◽  
Receptor Blockers ◽  
Dopamine Supersensitivity

Dopamine supersensitivity psychosis (DSP) frequently arises with long-term antipsychotic treatment and accounts for a significant proportion of treatment-resistant schizophrenia. The mechanism underlying DSP is thought to be a compensatory increase in dopamine receptor density in the striatum caused by long-term antipsychotic treatment. Previous animal studies have reported that antipsychotics increase serotonin 5-HT2A receptor density in the striatum and that 5-HT2A receptor blockers suppress dopamine-sensitive psychomotor activity, which may be linked to the pathophysiology of DSP. In this paper, we describe a patient who was hospitalised with treatment-resistant schizophrenia. Following treatment with high-dose antipsychotic polypharmacy for 10 weeks, the patient experienced worsening of psychotic and extrapyramidal symptoms. The patient was then started on second-generation antipsychotic asenapine while other antipsychotics were tapered off, resulting in improvement of these symptoms. Retrospectively, we presumed that the high-dose antipsychotic polypharmacy caused DSP, which was effectively treated by the potent 5-HT2A receptor antagonism of asenapine.

Effect of routine iron–folic acid supplementation among rural pregnant women living in low- and high-groundwater-iron areas in Bangladesh

2019 ◽  
Vol 22 (15) ◽  
pp. 2844-2855 ◽  
Author(s):  
Faruk Ahmed ◽  
Moududur Rahman Khan ◽  
Ireen Akhtar Chowdhury ◽  
Rubhana Raqib ◽  
Anjan Kumar Roy ◽  
...  
Keyword(s):  
Folic Acid ◽  
Pregnant Women ◽  
Significant Proportion ◽  
Significant Risk ◽  
Folic Acid Supplementation ◽  
Fe Deficiency ◽  
Prospective Longitudinal Study ◽  
Iron Folic Acid ◽  
Hb Concentration ◽  
Prospective Longitudinal

AbstractObjective:The present study investigated the risks and benefits of routine Fe–folic acid (IFA) supplementation in pregnant women living in low- and high-groundwater-Fe areas in Bangladesh.Design:A case-controlled prospective longitudinal study design was used to compare the effect of daily Fe (60 mg) and folic acid (400 μg) supplementation for 3·5 months.Setting:A rural community in Bangladesh.Participants:Pregnant women living in low-groundwater-Fe areas (n 260) and high-groundwater-Fe areas (n 262).Results:Mean Hb and serum ferritin concentrations at baseline were significantly higher in pregnant women in the high-groundwater-Fe areas. After supplementation, the mean change in Hb concentration in the women in the low-groundwater-Fe areas (0·10 mg/dl) was higher than that in the pregnant women in the high-groundwater-Fe areas (–0·08 mg/dl; P = 0·052). No significant changes in the prevalence of anaemia or Fe deficiency (ID) in either group were observed after IFA supplementation; however, the prevalence of Fe-deficiency anaemia (IDA) decreased significantly in the women in the low-groundwater-Fe areas. The risk of anaemia, ID and IDA after supplementation did not differ significantly between the groups. None of the participants had Fe overload. However, a significant proportion of the women in the high- and low-groundwater-Fe areas remained anaemic and Fe-deficient after supplementation.Conclusion:IFA supplementation significantly increased the Hb concentration in pregnant women living in the low-groundwater-Fe areas. Routine supplementation with 60 mg Fe and 400 μg folic acid does not pose any significant risk of haemoconcentration or Fe overload. Further research to identify other nutritional and non-nutritional contributors to anaemia is warranted to prevent and treat anaemia.

scholarly journals The Relative Role of Toxins A and B in the Virulence of Clotridioides difficile

2020 ◽  
Vol 10 (1) ◽  
pp. 96
Author(s):  
Andrew M. Skinner ◽  
S. Tyler Phillips ◽  
Michelle M. Merrigan ◽  
Kevin J. O’Leary ◽  
Susan P. Sambol ◽  
...  
Keyword(s):  
Animal Studies ◽  
Specific Treatment ◽  
Restriction Endonuclease Analysis ◽  
Natural Occurrence ◽  
Relative Role ◽  
Intestinal Epithelial ◽  
Large Molecular Weight ◽  
Stool Samples ◽  
Serious Disease ◽  
Isogenic Mutants

Most pathogenic strains of C. difficile possess two large molecular weight single unit toxins with four similar functional domains. The toxins disrupt the actin cytoskeleton of intestinal epithelial cells leading to loss of tight junctions, which ultimately manifests as diarrhea in the host. While initial studies of purified toxins in animal models pointed to toxin A (TcdA) as the main virulence factor, animal studies using isogenic mutants demonstrated that toxin B (TcdB) alone was sufficient to cause disease. In addition, the natural occurrence of TcdA−/TcdB+ (TcdA−/B+)mutant strains was shown to be responsible for cases of C. difficile infection (CDI) with symptoms identical to CDI caused by fully toxigenic (A+/B+) strains. Identification of these cases was delayed during the period when clinical laboratories were using immunoassays that only detected TcdA (toxA EIA). Our hospital laboratory at the time performed culture as well as toxA EIA on patient stool samples. A total of 1.6% (23/1436) of all clinical isolates recovered over a 2.5-year period were TcdA−/B+ variants, the majority of which belonged to the restriction endonuclease analysis (REA) group CF and toxinotype VIII. Despite reports of serious disease due to TcdA−/B+ CF strains, these infections were typically mild, often not requiring specific treatment. While TcdB alone may be sufficient to cause disease, clinical evidence suggests that both toxins have a role in disease.

scholarly journals Nutritional programming of gastrointestinal tract development. Is the pig a good model for man?

2010 ◽  
Vol 23 (1) ◽  
pp. 4-22 ◽  
Author(s):  
Paul Guilloteau ◽  
Romuald Zabielski ◽  
Harald M. Hammon ◽  
Cornelia C. Metges
Keyword(s):  
Gastrointestinal Tract ◽  
Animal Models ◽  
Animal Studies ◽  
Reference Model ◽  
Human Subjects ◽  
Mammalian Species ◽  
Epidemiological Studies ◽  
Long Term Effects ◽  
Nutritional Programming ◽  
The Impact

The consequences of early-life nutritional programming in man and other mammalian species have been studied chiefly at the metabolic level. Very few studies, if any, have been performed in the gastrointestinal tract (GIT) as the target organ, but extensive GIT studies are needed since the GIT plays a key role in nutrient supply and has an impact on functions of the entire organism. The possible deleterious effects of nutritional programming at the metabolic level were discovered following epidemiological studies in human subjects, and confirmed in animal models. Investigating the impact of programming on GIT structure and function would need appropriate animal models due to ethical restrictions in the use of human subjects. The aim of the present review is to discuss the use of pigs as an animal model as a compromise between ethically acceptable animal studies and the requirement of data which can be interpolated to the human situation. In nutritional programming studies, rodents are the most frequently used model for man, but GIT development and digestive function in rodents are considerably different from those in man. In that aspect, the pig GIT is much closer to the human than that of rodents. The swine species is closely comparable with man in many nutritional and digestive aspects, and thus provides ample opportunity to be used in investigations on the consequences of nutritional programming for the GIT. In particular, the ‘sow–piglets’ dyad could be a useful tool to simulate the ‘human mother–infant’ dyad in studies which examine short-, middle- and long-term effects and is suggested as the reference model.

scholarly journals Developmental Neurotoxicity of Environmentally Relevant Pharmaceuticals and Mixtures Thereof in a Zebrafish Embryo Behavioural Test

2021 ◽  
Vol 18 (13) ◽  
pp. 6717
Author(s):  
Alessandro Atzei ◽  
Ingrid Jense ◽  
Edwin P. Zwart ◽  
Jessica Legradi ◽  
Bastiaan J. Venhuis ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Animal Studies ◽  
Zebrafish Embryo ◽  
Cumulative Effect ◽  
Developmental Neurotoxicity ◽  
Limited Information ◽  
Behavioural Phenotype ◽  
Chemically Induced ◽  
Behavioural Test

Humans are exposed daily to complex mixtures of chemical substances via food intake, inhalation, and dermal contact. Developmental neurotoxicity is an understudied area and entails one of the most complex areas in toxicology. Animal studies for developmental neurotoxicity (DNT) are hardly performed in the context of regular hazard studies, as they are costly and time consuming and provide only limited information as to human relevance. There is a need for a combination of in vitro and in silico tests for the assessment of chemically induced DNT in humans. The zebrafish (Danio rerio) embryo (ZFE) provides a powerful model to study DNT because it shows fast neurodevelopment with a large resemblance to the higher vertebrate, including the human system. One of the suitable readouts for DNT testing in the zebrafish is neurobehaviour (stimulus-provoked locomotion) since this provides integrated information on the functionality and status of the entire nervous system of the embryo. In the current study, environmentally relevant pharmaceuticals and their mixtures were investigated using the zebrafish light-dark transition test. Zebrafish embryos were exposed to three neuroactive compounds of concern, carbamazepine (CBZ), fluoxetine (FLX), and venlafaxine (VNX), as well as their main metabolites, carbamazepine 10,11-epoxide (CBZ 10,11E), norfluoxetine (norFLX), and desvenlafaxine (desVNX). All the studied compounds, except CBZ 10,11E, dose-dependently inhibited zebrafish locomotor activity, providing a distinct behavioural phenotype. Mixture experiments with these pharmaceuticals identified that dose addition was confirmed for all the studied binary mixtures (CBZ-FLX, CBZ-VNX, and VNX-FLX), thereby supporting the zebrafish embryo as a model for studying the cumulative effect of chemical mixtures in DNT. This study shows that pharmaceuticals and a mixture thereof affect locomotor activity in zebrafish. The test is directly applicable in environmental risk assessment; however, further studies are required to assess the relevance of these findings for developmental neurotoxicity in humans.

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