77 results on '"Njau S"'
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2. A DIALLEL CROSS-BASED ANALYSIS OF THE GENETIC BASIS OF POD QUALITY AND POD YIELD IN SNAP BEAN.
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Njau, S. N., Arunga, E. E., and Otsyula, R.
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GREEN bean , *SUSTAINABLE agriculture , *GENE expression , *COMMON bean , *INCOME , *BEANS , *CULTIVARS - Abstract
Snap bean (Phaseolus vulgaris L.) is among the leading vegetables in Kenya that is mainly grown for export with the potential to increase household income. There are few programs in Kenya that focus on breeding new cultivars for increased production. The development of snap bean varieties that are resilient to the changing climate is crucial for sustainable agriculture in Kenya. To achieve this, knowledge of gene action, trait expression, and heritability is vital in effective breeding for quantitative traits like pod quality and yield. A study was conducted to investigate the inheritance of pod quality and yield traits in snap beans, which can inform the breeding of snap beans. A half diallel cross involving two indeterminate dry beans (G2333 and MCM 5001) and five determinate snap beans (Amy, Moonstone, Seagull, Serengeti and Vanilla) varieties was conducted. Data on pod traits (pod weight per plant, pod number per plant, pod length, pod diameter, pod wall fiber and pod suture string) were collected from 21 F1s and 7 parents grown in two locations (Embu and Kirinyaga Counties) in Kenya. The results showed significant genotypic and environmental effects (P < 0.001) for all traits, with significant genotype by environment (G × E) interactions for most traits. Additionally, general combining abilities (GCA) and specific combining abilities (SCA) were significant for all traits evaluated. The significance of GCA and SCA indicated the importance of both additive and non-additive gene effects in controlling the traits, although the additive gene effects were predominant. The study revealed that Vanilla and Serengeti had the highest GCA estimate for pod quality traits, while G2333 and MCM5001 had the highest GCA estimate for pod yield traits. Snap bean pod yield and quality are quantitative traits controlled by multiple genes and influenced by the environment. Therefore, the predominance of additive gene effects suggests that selection for these traits in segregating generations could yield satisfactory gains. The results of this study could impact the development of snap bean varieties that are more resilient to the effects of climate change. Thus, improving the sustainability and productivity of the agriculture sector in Kenya. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Electroconvulsive therapy and structural neuroplasticity in neocortical, limbic and paralimbic cortex.
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Pirnia, T, Joshi, SH, Leaver, AM, Vasavada, M, Njau, S, Woods, RP, Espinoza, R, and Narr, KL
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Limbic System ,Gyrus Cinguli ,Parahippocampal Gyrus ,Entorhinal Cortex ,Neocortex ,Temporal Lobe ,Humans ,Image Interpretation ,Computer-Assisted ,Magnetic Resonance Imaging ,Treatment Outcome ,Dominance ,Cerebral ,Electroconvulsive Therapy ,Neuronal Plasticity ,Reference Values ,Adult ,Middle Aged ,Female ,Male ,Neurosciences ,Depression ,Mental Health ,Brain Disorders ,Image Interpretation ,Computer-Assisted ,Dominance ,Cerebral ,Psychology ,Clinical Sciences ,Public Health and Health Services - Abstract
Electroconvulsive therapy (ECT) is a highly effective and rapidly acting treatment for severe depression. To understand the biological bases of therapeutic response, we examined variations in cortical thickness from magnetic resonance imaging (MRI) data in 29 patients scanned at three time points during an ECT treatment index series and in 29 controls at two time points. Changes in thickness across time and with symptom improvement were evaluated at high spatial resolution across the cortex and within discrete cortical regions of interest. Patients showed increased thickness over the course of ECT in the bilateral anterior cingulate cortex (ACC), inferior and superior temporal, parahippocampal, entorhinal and fusiform cortex and in distributed prefrontal areas. No changes across time occurred in controls. In temporal and fusiform regions showing significant ECT effects, thickness differed between patients and controls at baseline and change in thickness related to therapeutic response in patients. In the ACC, these relationships occurred in treatment responders only, and thickness measured soon after treatment initiation predicted the overall ECT response. ECT leads to widespread neuroplasticity in neocortical, limbic and paralimbic regions and changes relate to the extent of antidepressant response. Variations in ACC thickness, which discriminate treatment responders and predict response early in the course of ECT, may represent a biomarker of overall clinical outcome. Because post-mortem studies show focal reductions in glial density and neuronal size in patients with severe depression, ECT-related increases in thickness may be attributable to neuroplastic processes affecting the size and/or density of neurons and glia and their connections.
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- 2016
4. Assessing sustainability factors of farmer seed production: a case of the Good Seed Initiative project in Tanzania
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Kansiime, M. K., Bundi, M., Nicodemus, J., Ochieng, J., Marandu, D., Njau, S. S., Kessy, R. F., Williams, F., Karanja, D., Tambo, J. A., and Romney, D.
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- 2021
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5. Properties of CA3 Dendritic Excrescences in Alzheimerʼs Disease
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Tsamis, K. I., Mytilinaios, D. G., Njau, S. N., Fotiou, D. F., Glaftsi, S., Costa, V., and Baloyannis, S. J.
- Published
- 2010
6. COMPARISON OF COOKING TIME OF COMMERCIAL BEAN VARIETIES AND NEW BREEDING LINES DEVELOPED IN EASTERN AFRICA
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Kimani, P. M., Komu, P., Njau, S. N., Kimani, P. M., Komu, P., and Njau, S. N.
- Abstract
INTRODUCTION Long cooking time is a major constraint to domestic bean consumers and the processing industry in eastern Africa because it requires more energy, time and increases the cost of production of processed dry bean products, and reduces their competitiveness with other grain legumes. Cooking time of dry beans can vary from 1½ to 8 hours depending on variety (Miles and Sonde, 2004; Kimani et al, 2005). However, little has been done to develop fast cooking bean varieties in eastern Africa (Kimani et al, 2005). Breeding fast cooking bean is now critical due to strong preference for fast cooking and processed foods especially in urban communities. Cooking time of commercial bean varieties grown in eastern Africa under controlled or comparable conditions is not known. Such information will provide a baseline against which improvement in cooking time can be measured. Our objective was to compare the cooking time of commercial varieties and new advanced bean lines selected for fast cooking at the University of Nairobi. MATERIALS AND METHODS Cooking time of 34 bean genotypes were determined using a Mattson cooker in the Food Science laboratory, Upper Kabete campus, University of Nairobi. The genotypes included 10 popular commercial varieties, seven recently released biofortified varieties and 17 advanced lines of diverse market classes selected for fast cooking (Table 1). The study genotypes represented the Andean and Mesoamerican gene pools and the major market classes grown in east, central and southern Africa. Beans were for soaked for 16 hours before cooking. Each trial was replicated three times. Data was analysed using Genstat software (v15).
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- 2017
7. Long-term safety and efficiency of endovascular repair in an adolescent patient with post-traumatic aortic pseudoaneurysm
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Leda Kovatsi, Bintoudi A, Njau S, Vasiliadis N, and Tsitouridis I
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Letters - Published
- 2011
8. Disposable pipette extraction for gas chromatographic determination of codeine, morphine, and 6-monoacetylmorphine in vitreous humor
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Kovatsi, L., Rentifis, K., Giannakis, D., Njau, S., and Samanidou, V.
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Vitreous Body/*chemistry ,Chromatography, Gas ,Morphine/analysis/*isolation & purification ,Diagnosis ,Codeine/analysis/*isolation & purification ,Humans ,Autopsy ,Solid Phase Extraction/*methods ,Forensic Toxicology/*methods ,Morphine Derivatives/analysis/*isolation & purification - Abstract
The availability of a sensitive and rapid analytical method for the determination of opiates, and other substances of forensic interest, in a variety of biological specimens is of utmost importance to forensic laboratories. Solid-phase extraction is very popular in the pre-treatment of forensic samples. Nevertheless, a new approach, disposable pipette extraction (DPX), is gaining increasing interest in sample preparation. DPX has already been applied to the analysis of drugs of abuse in common biological matrices, such as urine and blood, but has not yet been evaluated on alternative biological samples, such as vitreous humor. The objective of this study was to evaluate the applicability of DPX on the analysis of opiates in vitreous humor. The currently developed method is fast, reliable, and easy to perform. The sensitivity, precision, and accuracy are satisfactory. Recoveries obtained are within the range of 72-91%, whereas the sample volume of vitreous humor required is only 100 muL. J Sep Sci
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- 2011
9. Endosulfan-induced lipid oxidation in Wistar rats: the protective action of vitamins C and E
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Njau S
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Pharmacology ,chemistry.chemical_compound ,chemistry ,Lipid oxidation ,Pharmacology (medical) ,Endosulfan - Published
- 2010
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10. Effect of chronic heroin and cocaine administration on global DNA methylation in brain and liver
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Fragou, D, Zanos, P, Kouidou, S, Njau, S, Kitchen, I, Bailey, A, Kovatsi, L, Fragou, D, Zanos, P, Kouidou, S, Njau, S, Kitchen, I, Bailey, A, and Kovatsi, L
- Published
- 2013
11. Drugs of Abuse: Epigenetic Mechanisms in Toxicity and Addiction
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Kovatsi, L., primary, Fragou, D., additional, Samanidou, V., additional, Njau, S., additional, and Kouidou, S., additional
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- 2011
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12. Lethal Hemorrhage Induced by A Pet Cat Scratch on Varicose Veins~!2010-01-06~!2010-01-23~!2010-04-21~!
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Apostolidou, C., primary, Koletsa, T., additional, Chatzinikolaou, F., additional, Psaroulis, D., additional, Njau, S. N., additional, and Kostopoulos, I., additional
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- 2010
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13. Mother-fetus postmortem toxicologic analysis in a fatal overdose with mecarbam.
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Tsoukali-Papadopoulou, H. and Njau, S.
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Self-poisoning -- Investigations ,Fetus ,Forensic toxicology -- Methods ,Drugs -- Overdose - Published
- 1987
14. THE COMBINATION OF SILVER TECHNIQUES FOR STUDYING THE PATHOLOGY OF ALZHEIMER'S DISEASE
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TSAMIS, K., primary, MYTILINAIOS, D., additional, NJAU, S. N., additional, PSAROULIS, D., additional, MAVROUDIS, J., additional, COSTA, V., additional, and BALOYANNIS, S. J., additional
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- 2008
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15. REELIN IMMUNOREACTIVITY AND MORPHOLOGICAL ANALYSIS OF THE HUMAN VISUAL CORTEX
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TSAMIS, K., primary, MYTILINAIOS, D., additional, PSAROULIS, D., additional, NJAU, S. N., additional, COSTA, V., additional, and BALOYANNIS, S. J., additional
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- 2007
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16. Evaluation of prooxidant-antioxidant balance in chronic heroin users in a single assay: an identification criterion for antioxidant supplementation.
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Kovatsi L, Njau S, Nikolaou K, Topouridou K, Papamitsou T, and Koliakos G
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- 2010
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17. Determination of opiates in postmortem bone and bone marrow
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Raikos, N., Tsoukali, H., and Njau, S. N.
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- 2001
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18. Magnesium, calcium and zinc fluctuations on skin induced injuries in correlation with time of induction
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Njau, S
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- 1991
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19. Loss of pod strings in common bean is associated with gene duplication, retrotransposon insertion and overexpression of PvIND.
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Parker TA, Cetz J, de Sousa LL, Kuzay S, Lo S, Floriani TO, Njau S, Arunga E, Duitama J, Jernstedt J, Myers JR, Llaca V, Herrera-Estrella A, and Gepts P
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- Domestication, Gene Duplication, Phenotype, Retroelements genetics, Phaseolus genetics
- Abstract
Fruit development has been central in the evolution and domestication of flowering plants. In common bean (Phaseolus vulgaris), the principal global grain legume staple, two main production categories are distinguished by fibre deposition in pods: dry beans, with fibrous, stringy pods; and stringless snap/green beans, with reduced fibre deposition, which frequently revert to the ancestral stringy state. Here, we identify genetic and developmental patterns associated with pod fibre deposition. Transcriptional, anatomical, epigenetic and genetic regulation of pod strings were explored through RNA-seq, RT-qPCR, fluorescence microscopy, bisulfite sequencing and whole-genome sequencing. Overexpression of the INDEHISCENT ('PvIND') orthologue was observed in stringless types compared with isogenic stringy lines, associated with overspecification of weak dehiscence-zone cells throughout the pod vascular sheath. No differences in DNA methylation were correlated with this phenotype. Nonstringy varieties showed a tandemly direct duplicated PvIND and a Ty1-copia retrotransposon inserted between the two repeats. These sequence features are lost during pod reversion and are predictive of pod phenotype in diverse materials, supporting their role in PvIND overexpression and reversible string phenotype. Our results give insight into reversible gain-of-function mutations and possible genetic solutions to the reversion problem, of considerable economic value for green bean production., (© 2022 The Authors. New Phytologist © 2022 New Phytologist Foundation.)
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- 2022
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20. Morphological alterations of the pyramidal and stellate cells of the visual cortex in schizophrenia.
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Mavroudis I, Petrides F, Kazis D, Chatzikonstantinou S, Karantali E, Ciobica A, Iordache AC, Dobrin R, Trus C, Njau S, Costa V, and Baloyannis S
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Schizophrenia is a severe brain disorder characterized by certain types of delusion, hallucination and thought disorder. Studies have revealed impaired synaptic plasticity and reduced gamma-aminobutyric acid levels of the visual cortex in patients with schizophrenia. While previous work established a critical role for interneurons and cortical connectivity in the generation of hallucinations, the present study set out to examine the morphology of pyramidal cells and interneurons from layers 3 and 4 in the primary visual cortex from schizophrenic brains and to identify any dendritic and spinal alterations in comparison to normal control brains. The morphological and morphometric changes of the pyramidal cells and the interneurons of the visual cortices of 10 brains obtained from patients with schizophrenia, in comparison to 10 age-matched controls, were studied using the Golgi method and 3D neuronal reconstruction techniques. Analysis using the Golgi impregnation technique revealed a significant loss of distal dendritic segments, tortuous branches and varicosities and an overall restriction of the dendritic field in the brains of schizophrenic patients in both pyramidal cells and in aspiny interneurons. The present results may explain certain clinical phenomena associated with the visual cortex usually encountered in schizophrenia., Competing Interests: The authors declare that they have no competing interests., (Copyright: © Mavroudis et al.)
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- 2021
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21. Subcallosal Cingulate Structural Connectivity Differs in Responders and Nonresponders to Electroconvulsive Therapy.
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Tsolaki E, Narr KL, Espinoza R, Wade B, Hellemann G, Kubicki A, Vasavada M, Njau S, and Pouratian N
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- Adult, Diffusion Magnetic Resonance Imaging, Female, Gyrus Cinguli, Humans, Magnetic Resonance Imaging, Male, Depressive Disorder, Major therapy, Electroconvulsive Therapy
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Background: Subcallosal cingulate (SCC) activity is associated with treatment response in major depressive disorder (MDD). Using electroconvulsive therapy (ECT) as a treatment model in this exploratory study, we addressed whether pretreatment SCC structural connectivity with corticolimbic-striatal circuitry relates to therapeutic outcome and whether these connectivity patterns change with treatment., Methods: Diffusion magnetic resonance imaging scans were acquired in 43 patients with MDD (mean [SD] age = 41 [13] years; men/women: 18/25) before and within 1 week of completing an ECT index series and in 31 healthy control subjects scanned twice (mean [SD] age = 38 [11] years; men/women: 17/18). Probabilistic tractography from subject-specific anatomically defined SCC seed regions to the ventral striatum (VS), anterior cingulate cortex (ACC), and bilateral medial prefrontal cortex (mPFC) was used to estimate structural connectivity in the target network., Results: SCC-mPFC connectivity was lower in responders (>50% symptom improvement) than nonresponders both before (p < .014) (difference 37%-96% left and right hemispheres) and after (p = .023) (difference 100% right hemisphere) treatment. SCC-mPFC connectivity in responders was also decreased compared with control subjects both at baseline (p = .012) and after ECT (p = .006), whereas nonresponders had SCC-right mPFC connectivity similar to that of control subjects. Subjects with MDD also showed decreased SCC-ACC connectivity compared with control subjects (baseline: p < .003, after ECT: p = .001), although SCC-ACC connectivity did not distinguish responders from nonresponders. Bilateral SCC-VS connectivity decreased (11%) with ECT (p = .021) regardless of treatment response., Conclusions: While SCC-ACC connectivity may be a hallmark of MDD compared with control subjects, lower pretreatment SCC-mPFC connectivity in ECT responders (compared with nonresponders and control subjects) suggests that connectivity in this pathway may serve as a potential biomarker of therapeutic outcome and be relevant for treatment selection., (Copyright © 2020 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)
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- 2021
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22. Acute changes in cerebral blood flow after single-infusion ketamine in major depression: a pilot study.
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Gonzalez S, Vasavada M, Njau S, Sahib AK, Espinoza R, Narr KL, and Leaver AM
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Background: Ketamine provides rapid antidepressant response in those struggling with major depressive disorder (MDD). This study measured acute changes in brain activity over 24 hours after a single infusion of ketamine using arterial spin labeled (ASL) functional magnetic resonance imaging (fMRI) in patients with MDD. ASL is a novel technique that provides quantitative values to measure cerebral blood flow (CBF)., Methods: A single sub-anesthetic dose (0.5 mg/kg) of ketamine was delivered intravenously. Treatment-refractory patients (n=11) were assessed at: Baseline (pre-infusion), and approximately 1hr, 6hrs, and 24hrs post-infusion. Linear mixed-effects models detected changes in CBF with respect to treatment outcome, and results were corrected for false discovery rate (FDR)., Results: After ketamine infusion, increased CBF was observed in the thalamus, while decreased CBF was observed in lateral occipital cortex in all patients. Time-by-response interactions were noted in ventral basal ganglia and medial prefrontal cortex, where CBF change differed according to antidepressant response., Limitations: Modest sample size is a limitation of this pilot study; strict statistical correction and visualization of single-subject data attempted to ameliorate this issue., Conclusion: In this pilot study, a sub-anesthetic dose of ketamine was associated with acute neurofunctional changes that may be consistent with altered attention, specifically increased thalamus activity coupled with decreased cortical activity. By contrast, antidepressant response to ketamine was associated with changes in reward-system regions, specifically ventral basal ganglia and medial prefrontal cortex. Further work is needed to determine whether these results generalize to larger samples and/or serial ketamine infusions associated with longer-lasting clinical effects., Competing Interests: DISCLOSURES The authors declare no conflicts of interest.
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- 2020
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23. Neural Subtypes of Euthymic Bipolar I Disorder Characterized by Emotion Regulation Circuitry.
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Njau S, Townsend J, Wade B, Hellemann G, Bookheimer S, Narr K, and Brooks JO 3rd
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- Amygdala, Cyclothymic Disorder, Humans, Prefrontal Cortex, Bipolar Disorder, Emotional Regulation
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Background: Current diagnostic strategy for bipolar disorders relies on symptomological classification. Yet, responses to both pharmacological and psychotherapeutic treatments vary widely, suggesting that underlying neuropathological differences are not well defined by current nosology. Classifying patients with bipolar disorder based on emotion regulation network (ERN) activation may account for some of the heterogeneity within the disorder., Methods: Euthymic participants diagnosed with bipolar I disorder (n = 86) and healthy subjects (n = 80) underwent functional magnetic resonance imaging scans while engaged in emotional reappraisal of negative stimuli. After determining average regional activations in key network regions, we applied agglomerative hierarchical clustering to identify subtypes of bipolar disorder. Next, we examined relations among neural subtypes, demographic variables, and mood symptoms., Results: Analyses revealed two primary neural subtypes of euthymic bipolar I disorder participants. The first subtype, ERN cluster 1, was characterized by increased amygdala activation and slightly increased ventrolateral prefrontal and subgenual cingulate activation, whereas ERN cluster 2 was defined by decreased amygdala activation with wider-spread prefrontal activation. Cluster 1 was associated with a higher number of hospitalizations for depression (odds ratio = 1.30, 95% confidence interval = 1.02-1.64) and later onset of manic episodes (odds ratio = 1.06, 95% confidence interval = 1.00-21.13) than cluster 2. ERN clusters of healthy subjects differed from bipolar disorder clusters and were defined by differential activation of the prefrontal cortex. ERN clusters of healthy subjects, which differed from bipolar disorder clusters, were defined by differential activation of the prefrontal cortex., Conclusions: Emotion regulation circuitry can distinguish neurobiological subtypes of bipolar disorder in the euthymic state. These subtypes, which are differentially associated with indices of illness severity and subsyndromal affective symptoms, may help to inform relapse risk and more personalized treatment approaches., (Copyright © 2020 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)
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- 2020
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24. Variations in Hippocampal White Matter Diffusivity Differentiate Response to Electroconvulsive Therapy in Major Depression.
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Kubicki A, Leaver AM, Vasavada M, Njau S, Wade B, Joshi SH, Loureiro J, Hellemann G, Woods RP, Espinoza R, and Narr KL
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- Adult, Diffusion Magnetic Resonance Imaging, Female, Humans, Male, Middle Aged, Treatment Outcome, Depressive Disorder, Major pathology, Depressive Disorder, Major therapy, Electroconvulsive Therapy, Hippocampus pathology, White Matter pathology
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Background: Electroconvulsive therapy (ECT) is an effective treatment for severe depression and is shown to increase hippocampal volume and modulate hippocampal functional connectivity. Whether variations in hippocampal structural connectivity occur with ECT and relate to clinical response is unknown., Methods: Patients with major depression (n = 36, 20 women, age 41.49 ± 13.57 years) underwent diffusion magnetic resonance imaging at baseline and after ECT. Control subjects (n = 32, 17 women, age 39.34 ± 12.27 years) underwent scanning twice. Functionally defined seeds in the left and right anterior hippocampus and probabilistic tractography were used to extract tract volume and diffusion metrics (fractional anisotropy and axial, radial, and mean diffusivity). Statistical analyses determined effects of ECT and time-by-response group interactions (>50% change in symptoms before and after ECT defined response). Differences between baseline measures across diagnostic groups and in association with treatment outcome were also examined., Results: Significant effects of ECT (all p < .01) and time-by-response group interactions (all p < .04) were observed for axial, radial, and mean diffusivity for right, but not left, hippocampal pathways. Follow-up analyses showed that ECT-related changes occurred in responders only (all p < .01) as well as in relation to change in mood examined continuously (all p < .004). Baseline measures did not relate to symptom change or differ between patients and control subjects. All measures remained stable across time in control subjects. No significant effects were observed for fractional anisotropy and volume., Conclusions: Structural connectivity of hippocampal neural circuits changed with ECT and distinguished treatment responders. The findings suggested neurotrophic, glial, or inflammatory response mechanisms affecting axonal integrity., (Copyright © 2018 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)
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- 2019
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25. Inflammation and Improvement of Depression Following Electroconvulsive Therapy in Treatment-Resistant Depression.
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Kruse JL, Congdon E, Olmstead R, Njau S, Breen EC, Narr KL, Espinoza R, and Irwin MR
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- Adult, Female, Humans, Interleukin-6 blood, Interleukin-8 blood, Male, Middle Aged, Severity of Illness Index, Tumor Necrosis Factor-alpha blood, C-Reactive Protein, Cytokines blood, Depressive Disorder, Major blood, Depressive Disorder, Major physiopathology, Depressive Disorder, Major therapy, Depressive Disorder, Treatment-Resistant blood, Depressive Disorder, Treatment-Resistant physiopathology, Depressive Disorder, Treatment-Resistant therapy, Electroconvulsive Therapy methods, Inflammation blood, Outcome Assessment, Health Care
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Objective: Electroconvulsive therapy (ECT) is the most robust acute treatment for severe major depressive disorder, yet clinical response is variable. Inflammation is associated with depression, especially in women, and levels of C-reactive protein (CRP) and interleukin (IL)-6 predict response to antidepressant medications. This study evaluated whether markers of inflammation predicted response to electroconvulsive therapy (ECT) in patients with treatment-resistant depression and to what extent this association differed between men and women., Methods: In patients (N = 29) who had a current major depressive episode diagnosed using DSM-IV-TR criteria and were scheduled to undergo ECT at an academic referral center, levels of CRP, IL-6, IL-8, and tumor necrosis factor-α and severity of depressive symptoms (Montgomery-Asberg Depression Rating Scale [MADRS]) were prospectively evaluated before ECT treatment, after the second ECT session, and again at the completion of the index treatment series. Data were collected between December 2011 and December 2014. The primary outcome was end-of-treatment MADRS score., Results: In multivariate analyses, higher levels of IL-6 at baseline, but not other inflammatory markers or clinical variables, were associated with lower end-of-treatment MADRS score (P = .01). When stratified by sex, IL-6 remained a significant predictor of end-of-treatment MADRS for women (P = .02) but not men (P = .1), and CRP emerged as a significant predictor for women (P = .04) but not men (P = .66). CRP and IL-6 increased from baseline to the second ECT session (P values < .01) and returned to baseline levels at end of treatment; these changes did not relate to MADRS score over the course of ECT., Conclusions: Levels of IL-6 prior to ECT treatment may be useful in identifying those depressed patients most likely to benefit from ECT treatment. In contrast, acute changes in IL-6 and CRP may reflect spikes in inflammatory response related to the initiation of seizure therapy, but not mood. Assessment of pretreatment inflammatory biomarkers, especially in women, might be useful in guiding treatment decision-making in treatment-resistant depression., (© Copyright 2018 Physicians Postgraduate Press, Inc.)
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- 2018
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26. Short- and Long-term Cognitive Outcomes in Patients With Major Depression Treated With Electroconvulsive Therapy.
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Vasavada MM, Leaver AM, Njau S, Joshi SH, Ercoli L, Hellemann G, Narr KL, and Espinoza R
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- Adult, Aged, Attention, Executive Function, Female, Humans, Male, Memory, Middle Aged, Neuropsychological Tests, Psychiatric Status Rating Scales, Recurrence, Treatment Outcome, Cognition, Depressive Disorder, Major psychology, Depressive Disorder, Major therapy, Electroconvulsive Therapy adverse effects, Electroconvulsive Therapy methods, Electroconvulsive Therapy psychology
- Abstract
Objectives: The risk of cognitive impairment is a concern for patients with major depressive disorder receiving electroconvulsive therapy (ECT). Here, we evaluate the acute, short-term and long-term effects of ECT on tests of processing speed, executive function, memory, and attention., Methods: Forty-four patients with major depressive disorder receiving ECT (61% right unilateral, 39% mixed right unilateral-bitemporal, left unilateral, and/or bitemporal lead placement) underwent a cognitive battery prior to ECT (T1), after 2 sessions (T2), and at the end of the index (T3). Thirty-two patients returned for a 6-month follow-up (T4). Thirty-three control subjects were assessed at 2 times approximately 4 weeks apart (C1 and C2)., Results: At baseline, patients showed deficits in processing speed, executive function, and memory compared with control subjects. Including depression severity and lead placement covariates, linear mixed-model analysis showed significant improvement in only processing speed between T1 and T3 and between T1 and T4 in patients. An acute decline in attention and verbal memory was observed at T2, but performance returned to baseline levels at T3. Longitudinal cognitive outcomes did not differ in patients defined as ECT responders/nonresponders., Limitations: Episodic memory was not measured, and medications were not controlled between T3 and T4. Control subjects also showed improvements in processing speed, suggesting practice effects for some measures., Conclusions: In this naturalistic ECT treatment study, results show that the initiation of ECT may transiently affect memory and executive function, but cognition is largely unaffected during and after ECT. Whereas some functions might improve, others will at least remain stable up to 6 months following the ECT index.
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- 2017
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27. DATA-DRIVEN CLUSTER SELECTION FOR SUBCORTICAL SHAPE AND CORTICAL THICKNESS PREDICTS RECOVERY FROM DEPRESSIVE SYMPTOMS.
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Wade BSC, Sui J, Njau S, Leaver AM, Vasvada M, Gutman BA, Thompson PM, Espinoza R, Woods RP, Abbott CC, Narr KL, and Joshi SH
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Patients with major depressive disorder (MDD) who do not achieve full symptomatic recovery after antidepressant treatment have a higher risk of relapse. Compared to pharmacotherapies, electroconvulsive therapy (ECT) more rapidly produces a greater extent of response in severely depressed patients. However, prediction of which candidates are most likely to improve after ECT remains challenging. Using structural MRI data from 42 ECT patients scanned prior to ECT treatment, we developed a random forest classifier based on data-driven shape cluster selection and cortical thickness features to predict remission. Right hemisphere hippocampal shape and right inferior temporal cortical thickness was most predictive of remission, with the predicted probability of recovery decreasing when these regions were thicker prior to treatment. Remission was predicted with an average 73% balanced accuracy. Classification of MRI data may help identify treatment-responsive patients and aid in clinical decision-making. Our results show promise for the development of personalized treatment strategies.
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- 2017
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28. Neurochemical correlates of rapid treatment response to electroconvulsive therapy in patients with major depression.
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Njau S, Joshi SH, Espinoza R, Leaver AM, Vasavada M, Marquina A, Woods RP, and Narr KL
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- Adult, Biomarkers cerebrospinal fluid, Bipolar Disorder diagnostic imaging, Bipolar Disorder metabolism, Bipolar Disorder therapy, Cross-Sectional Studies, Depressive Disorder, Major diagnostic imaging, Female, Follow-Up Studies, Gyrus Cinguli diagnostic imaging, Hippocampus diagnostic imaging, Humans, Longitudinal Studies, Male, Proton Magnetic Resonance Spectroscopy, Psychiatric Status Rating Scales, Regression Analysis, Treatment Outcome, Depressive Disorder, Major metabolism, Depressive Disorder, Major therapy, Electroconvulsive Therapy, Gyrus Cinguli metabolism, Hippocampus metabolism
- Abstract
Background: Electroconvulsive therapy (ECT) is a highly effective brain stimulation treatment for severe depression. Identifying neurochemical changes linked with ECT may point to biomarkers and predictors of successful treatment response., Methods: We used proton magnetic resonance spectroscopy (1H-MRS) to measure longitudinal changes in glutamate/glutamine (Glx), creatine (Cre), choline (Cho) and N -acetylaspartate (NAA) in the dorsal (dACC) and subgenual anterior cingulate cortex (sgACC) and bilateral hippocampus in patients receiving ECT scanned at baseline, after the second ECT session and after the ECT treatment series. Patients were compared with demographically similar controls at baseline. Controls were assessed twice to establish normative values and variance., Results: We included 50 patients (mean age 43.78 ± 14 yr) and 33 controls (mean age 39.33 ± 12 yr) in our study. Patients underwent a mean of 9 ± 4.1 sessions of ECT. At baseline, patients showed reduced Glx in the sgACC, reduced NAA in the left hippocampus and increased Glx in the left hippocampus relative to controls. ECT was associated with significant increases in Cre in the dACC and sgACC and decreases in NAA in the dACC and right hippocampus. Lower NAA levels in the dACC at baseline predicted reductions in depressive symptoms. Both ECT and symptom improvement were associated with decreased Glx in the left hippocampus and increased Glx in the sgACC., Limitations: Attrition and clinical heterogeneity may have masked more subtle findings., Conclusion: ECT elicits robust effects on brain chemistry, impacting Cre, NAA and Glx, which suggests restorative and neurotrophic processes. Differential effects of Glx in the sgACC and hippocampus, which approach control values with treatment, may reflect previously implicated underactive cortical and overactive subcortical limbic circuitry in patients with major depression. NAA levels at baseline are predictive of therapeutic outcome and could inform future treatment strategies.
- Published
- 2017
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29. Desynchronization and Plasticity of Striato-frontal Connectivity in Major Depressive Disorder.
- Author
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Leaver AM, Espinoza R, Joshi SH, Vasavada M, Njau S, Woods RP, and Narr KL
- Abstract
Major depressive disorder (MDD) is associated with dysfunctional corticolimbic networks, making functional connectivity studies integral for understanding the mechanisms underlying MDD pathophysiology and treatment. Resting-state functional connectivity (RSFC) studies analyze patterns of temporally coherent intrinsic brain activity in "resting-state networks" (RSNs). The default-mode network (DMN) has been of particular interest to depression research; however, a single RSN is unlikely to capture MDD pathophysiology in its entirety, and the DMN itself can be characterized by multiple RSNs. This, coupled with conflicting previous results, underscores the need for further research. Here, we measured RSFC in MDD by targeting RSNs overlapping with corticolimbic regions and further determined whether altered patterns of RSFC were restored with electroconvulsive therapy (ECT). MDD patients exhibited hyperconnectivity between ventral striatum (VS) and the ventral default-mode network (vDMN), while simultaneously demonstrating hypoconnectivity with the anterior DMN (aDMN). ECT influenced this pattern: VS-vDMN hyperconnectivity was significantly reduced while VS-aDMN hypoconnectivity only modestly improved. RSFC between the salience RSN and dorsomedial prefrontal cortex was also reduced in MDD, but was not affected by ECT. Taken together, our results support a model of ventral/dorsal imbalance in MDD and further suggest that the VS is a key structure contributing to this desynchronization., (© The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2016
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30. Variations in myo-inositol in fronto-limbic regions and clinical response to electroconvulsive therapy in major depression.
- Author
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Njau S, Joshi SH, Leaver AM, Vasavada M, Van Fleet J, Espinoza R, and Narr KL
- Subjects
- Adult, Cross-Sectional Studies, Depressive Disorder, Major diagnostic imaging, Female, Frontal Lobe diagnostic imaging, Humans, Limbic System diagnostic imaging, Linear Models, Magnetic Resonance Spectroscopy, Male, Middle Aged, Tritium metabolism, Depressive Disorder, Major pathology, Depressive Disorder, Major therapy, Electroconvulsive Therapy methods, Frontal Lobe metabolism, Inositol metabolism, Limbic System metabolism
- Abstract
Though electroconvulsive therapy (ECT) is an established treatment for severe depression, the neurobiological factors accounting for the clinical effects of ECT are largely unknown. Myo-inositol, a neurometabolite linked with glial activity, is reported as reduced in fronto-limbic regions in patients with depression. Whether changes in myo-inositol relate to the antidepressant effects of ECT is unknown. Using magnetic resonance spectroscopy ((1)H-MRS), we measured dorsomedial anterior cingulate cortex (dmACC) and left and right hippocampal myo-inositol in 50 ECT patients (mean age: 43.78, 14 SD) and 33 controls (mean age: 39.33, 12 SD) to determine cross sectional effects of diagnosis and longitudinal effects of ECT. Patients were scanned prior to treatment, after the second ECT and at completion of the ECT index series. Controls were scanned twice at intervals corresponding to patients' baseline and end of treatment scans. Myo-inositol increased over the course of ECT in the dmACC (p = 0.042). A significant hemisphere by clinical response effect was observed for the hippocampus (p = 0.003) where decreased myo-inositol related to symptom improvement in the left hippocampus. Cross-sectional differences between patients and controls at baseline were not detected. Changes in myo-inositol observed in the dmACC in association with ECT and in the hippocampus in association with ECT-related clinical response suggest the mechanisms of ECT could include gliogenesis or a reversal of gliosis that differentially affect dorsal and ventral limbic regions. Change in dmACC myo-inositol diverged from control values with ECT suggesting compensation, while hippocampal change suggested normalization., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
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31. Effect of Electroconvulsive Therapy on Striatal Morphometry in Major Depressive Disorder.
- Author
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Wade BS, Joshi SH, Njau S, Leaver AM, Vasavada M, Woods RP, Gutman BA, Thompson PM, Espinoza R, and Narr KL
- Subjects
- Adult, Area Under Curve, Corpus Striatum diagnostic imaging, Cross-Sectional Studies, Depressive Disorder, Major diagnostic imaging, Female, Humans, Image Processing, Computer-Assisted, Longitudinal Studies, Magnetic Resonance Imaging, Male, Middle Aged, Psychiatric Status Rating Scales, Time Factors, Treatment Outcome, Corpus Striatum pathology, Depressive Disorder, Major pathology, Depressive Disorder, Major therapy, Electroconvulsive Therapy methods
- Abstract
Patients with major depression show reductions in striatal and paleostriatal volumes. The functional integrity and connectivity of these regions are also shown to change with antidepressant response. Electroconvulsive therapy (ECT) is a robust and rapidly acting treatment for severe depression. However, whether morphological changes in the dorsal and ventral striatum/pallidum relate to or predict therapeutic response to ECT is unknown. Using structural MRI, we assessed cross-sectional effects of diagnosis and longitudinal effects of ECT for volume and surface-based shape metrics of the caudate, putamen, pallidum, and nucleus accumbens in 53 depressed patients (mean age: 44.1 years, 13.8 SD; 52% female) and 33 healthy controls (mean age: 39.3 years, 12.4 SD; 57% female). Patients were assessed before ECT, after their second ECT, and after completing an ECT treatment index. Controls were evaluated at two time points. Support vector machines determined whether morphometric measures at baseline predicted ECT-related clinical response. Patients showed smaller baseline accumbens and pallidal volumes than controls (P<0.05). Increases in left putamen volume (P<0.03) occurred with ECT. Global increases in accumbens volume and local changes in pallidum and caudate volume occurred in patients defined as treatment responders. Morphometric changes were absent across time in controls. Baseline volume and shape metrics predicted overall response to ECT with up to 89% accuracy. Results support that ECT elicits structural plasticity in the dorsal and ventral striatum/pallidum. The morphometry of these structures, forming key components of limbic-cortical-striatal-pallidal-thalamic circuitry involved in mood and emotional regulation, may determine patients likely to benefit from treatment.
- Published
- 2016
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32. The effect of opioid dependence on conventional and novel biochemical parameters of bone metabolism.
- Author
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Balodimos S, Nikolaou K, Njau S, Karamouzis M, and Kovatsi L
- Subjects
- Adult, Biomarkers blood, Case-Control Studies, Hepatitis C blood, Hepatitis C complications, Hepatitis C Antibodies blood, Humans, Male, Opioid-Related Disorders complications, Young Adult, Alkaline Phosphatase blood, Bone and Bones metabolism, Calcium blood, Opioid-Related Disorders blood, Parathyroid Hormone blood, Peptide Fragments blood, Phosphorus blood, Procollagen blood
- Abstract
Background: Opioids influence bone metabolism in several ways and osteoporosis associated with the long-term use of opioids is believed to be multifactorial., Objectives: To investigate the effect of opioid dependence on conventional and novel biochemical parameters of bone metabolism. To evaluate whether the concomitant HCV infection affects these parameters., Methods: Fifty-nine opioid-dependent subjects and 23 healthy volunteers participated in the study. Parameters of bone metabolism were determined in serum. The determined parameters were procollagen type I N-terminal propeptide (PINP), serum Beta-Crosslaps Ι (β-CTX), total calcium (Ca), inorganic phosphorus (P), parathormone (PTH) and alkaline phosphatase bone isoenzyme (ALP)., Results: The results of our study show that opioid-dependent subjects exhibit higher values in those biochemical markers that are indicative of increased osteoclast activity, such as β-CTX and ALP, compared to healthy subjects. Furthermore, in opioid-dependent subjects the values of PTH were lower, while those of PINP were higher, in comparison to healthy individuals. No significant difference in the studied parameters was found when opioid-dependent subjects positive for anti-HCV antibodies were compared with opioid-dependent subjects negative for anti-HCV antibodies., Conclusion: Our findings show that there is increased bone turnover (bone metabolism) in opioid-dependent subjects, compared to healthy individuals. Future research on bone mineral density in these patients will help us evaluate whether the bone remodeling process is balanced or not.
- Published
- 2015
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33. Recent advances in the bioanalysis of modified nucleotides in epigenetic studies.
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Fragou D, Fragou A, Samanidou V, Kouidou S, Njau S, and Kovatsi L
- Subjects
- 5-Methylcytosine analogs & derivatives, Animals, Chromatography, High Pressure Liquid methods, Cytosine analogs & derivatives, Cytosine analysis, DNA genetics, Humans, Immunohistochemistry methods, In Situ Hybridization, Fluorescence methods, DNA chemistry, DNA Methylation, Epigenesis, Genetic, Nucleotides analysis, Nucleotides genetics
- Abstract
Epigenetic alterations, such as DNA methylation, are involved in the pathogenesis of various diseases, the toxicity of diverse agents, the process of aging, the development of stem cells and numerous other mechanisms. DNA methylation is one of the most well-studied epigenetic alterations in mammals. Nevertheless, the scientific interest is now focusing on novel modified nucleotides with potential regulatory roles, such as 5-hydroxymethylcytosine. We currently present and discuss novel bioanalytical strategies developed for the determination of various modified nucleotides in epigenetic studies.
- Published
- 2013
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34. Alterations in serum MMP and TIMP concentrations following chronic heroin abuse.
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Kovatsi L, Batzios S, Nikolaou K, Fragou D, Njau S, Tsatsakis A, Karakiulakis G, and Papakonstantinou E
- Subjects
- Adult, Chronic Disease, Humans, Male, Middle Aged, Prospective Studies, Young Adult, Heroin Dependence blood, Matrix Metalloproteinases blood, Tissue Inhibitor of Metalloproteinases blood
- Abstract
Unlabelled: Abstract Context: Although opiate abuse is known to affect matrix metalloproteinases (MMPs), data on these enzymes and their tissue inhibitors in heroin addicts are scarce., Objective: In the present study, we determined serum concentrations of MMP-2, MMP-9, tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2 in heroin users, and compared them with healthy individuals. We evaluated whether 21 d of abstinence are adequate to reverse the effect of opiates and we compared seropositive with seronegative, for anti-HCV antibodies, heroin users., Materials and Methods: Twenty-six heroin-dependent male volunteers and an equal number of healthy individuals participated in this study. ELISA was used to assess the serum levels of MMP-2, MMP-9, TIMP-1 and TIMP-2. Heroin users were assessed both upon admission and upon completion of a 21-d detoxification program., Results: Serum TIMP-1 concentrations were significantly lower and the ratios MMP-2/TIMP-1, MMP-9/TIMP-1 and MMP-2/TIMP-2 were significantly higher in heroin users compared to healthy individuals. Heroin users who were seropositive had lower MMP concentrations, as well as lower MMP/TIMP ratios, compared to those who were seronegative., Discussion: Our results showed that in heroin-addicted individuals, and especially those who are positive for anti-HCV antibodies, the balance between MMPs and TIMPs in serum is disrupted and this disruption cannot be restored within 21 d of abstinence., Conclusion: Chronic heroin abuse disrupts the balance between MMPs and TIMPs in serum and this effect is not reversible within 21 d of abstinence.
- Published
- 2013
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35. Effect of chronic heroin and cocaine administration on global DNA methylation in brain and liver.
- Author
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Fragou D, Zanos P, Kouidou S, Njau S, Kitchen I, Bailey A, and Kovatsi L
- Subjects
- Animals, Biomarkers metabolism, Brain metabolism, Brain pathology, Chromatography, High Pressure Liquid, Cocaine-Related Disorders pathology, Deoxycytidine analogs & derivatives, Deoxycytidine metabolism, Disease Models, Animal, Heroin Dependence pathology, Liver metabolism, Liver pathology, Male, Mice, Mice, Inbred C57BL, Spectrophotometry, Ultraviolet, Time Factors, Brain drug effects, Cocaine toxicity, Cocaine-Related Disorders genetics, DNA Methylation drug effects, Heroin toxicity, Heroin Dependence genetics, Liver drug effects
- Abstract
Drug abuse is associated with epigenetic changes, such as histone modifications and DNA methylation. The purpose of the present study was to examine the effect of chronic cocaine and heroin administration on global DNA methylation in brain and liver. Male, 8 week old, C57BL/6J mice received heroin in a chronic 'intermittent' escalating dose paradigm, or cocaine in a chronic escalating dose 'binge' paradigm, which mimic the human pattern of opioid or cocaine abuse respectively. Following sacrifice, livers and brains were removed and DNA was extracted from them. The extracted DNA was hydrolyzed and 2'-deoxycytidine and 5-methyl-2'-deoxycytidine were determined by HPLC-UV. The % 5-methyl-2'-deoxycytidine content of DNA was significantly higher in the brain compared to the liver. There were no differences between the control animals and the cocaine or heroin treated animals in neither of the tissues examined, which is surprising since cocaine administration induced gross morphological changes in the liver. Moreover, there was no difference in the % 5-methyl-2'-deoxycytidine content of DNA between the cocaine and the heroin treated animals. The global DNA methylation status in the brain and liver of mice chronically treated with cocaine or heroin remains unaffected, but this finding cannot exclude the existence of anatomical region or gene-specific methylation differences. This is the first time that global DNA methylation in the liver and whole brain has been studied following chronic cocaine or heroin treatment., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2013
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36. Disposable pipette extraction for the simultaneous determination of biperiden and three antipsychotic drugs in human urine by GC-nitrogen phosphorus detection.
- Author
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Samanidou V, Stathatos C, Njau S, and Kovatsi L
- Subjects
- Antipsychotic Agents chemistry, Biperiden chemistry, Chromatography, Gas, Humans, Nitrogen analysis, Phosphorus analysis, Reproducibility of Results, Time Factors, Analytic Sample Preparation Methods instrumentation, Antipsychotic Agents isolation & purification, Antipsychotic Agents urine, Biperiden isolation & purification, Biperiden urine, Disposable Equipment, Urinalysis instrumentation
- Abstract
Background: Disposable pipette extraction with reversed-phase sorbent is proposed for the fast and simple GC determination of the antipsychotic drugs chlorpromazine, olanzapine, clozapine and biperiden - an anticholinergic drug - in human urine. The method was validated and successfully applied to postmortem urine samples. The analytical run was 11 min and lidocaine was used as the internal standard., Results: The developed method showed good linearity, over the range of 0.34 to 5 ng/µl, for all compounds. The within-day and between-day precision and accuracy assays revealed values ≤15%, while the recoveries ranged from 85 to 120%. LOD and LOQ ranged from 0.28 to 0.42 ng/µl and from 0.85 to 3.58 ng/µl, respectively., Conclusion: The developed method is a user-friendly technique, which is simple and fast.
- Published
- 2013
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37. Atypical antipsychotics: trends in analysis and sample preparation of various biological samples.
- Author
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Fragou D, Dotsika S, Sarafidou P, Samanidou V, Njau S, and Kovatsi L
- Subjects
- Antipsychotic Agents pharmacology, Chemistry Techniques, Analytical trends, Humans, Antipsychotic Agents analysis, Antipsychotic Agents chemistry, Chemistry Techniques, Analytical methods
- Abstract
Atypical antipsychotics are increasingly popular and increasingly prescribed. In some countries, they can even be obtained over-the-counter, without a prescription, making their abuse quite easy. Although atypical antipsychotics are thought to be safer than typical antipsychotics, they still have severe side effects. Intoxications are not rare and some of them have a fatal outcome. Drug interactions involving atypical antipsychotics complicate patient management in clinical settings and the determination of the cause of death in fatalities. In view of the above, analytical strategies that can efficiently isolate atypical antipsychotics from a variety of biological samples and quantify them accurately, sensitively and reliably, are of utmost importance both for the clinical, as well as for the forensic toxicologist. In this review, we will present and discuss novel analytical strategies that have been developed from 2004 to the present day for the determination of atypical antipsychotics in various biological samples.
- Published
- 2012
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38. A simple HPLC method for the simultaneous determination of two selective serotonin reuptake inhibitors and two serotonin-norepinephrine reuptake inhibitors in hair, nail clippings, and cerebrospinal fluid.
- Author
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Samanidou V, Pantazidou K, Kovatsi L, Njau S, and Livanos A
- Subjects
- Biological Transport, Cyclohexanols analysis, Duloxetine Hydrochloride, Fluoxetine analysis, Humans, Norepinephrine metabolism, Paroxetine analysis, Selective Serotonin Reuptake Inhibitors cerebrospinal fluid, Thiophenes analysis, Venlafaxine Hydrochloride, Adrenergic Uptake Inhibitors analysis, Cerebrospinal Fluid chemistry, Chromatography, High Pressure Liquid methods, Hair chemistry, Nails chemistry, Selective Serotonin Reuptake Inhibitors analysis
- Abstract
A novel and simple high-performance liquid chromatography method has been developed for the simultaneous determination of two selective serotonin reuptake inhibitors (fluoxetine and paroxetine) and two serotonin-norepinephrine reuptake inhibitors (venlafaxine and duloxetine) in alternative samples of toxicological interest such as hair, nail clippings, and cerebrospinal fluid (CSF). The separation was achieved on a Hichrom Kromasil 100-5C(18) (250 × 4.6 mm) 5 μm column by using ammonium acetate (0.05 M)-acetonitrile (59:41% v/v) as the mobile phase, delivered isocratically at a flow rate of 1.3 mL/min, within ca. 10 min. Ultraviolet detection at 235 nm was used for monitoring the eluting analytes. Validation was performed in terms of linearity, selectivity, accuracy, precision, and stability. Correlation coefficients were greater than 0.9954. The limits of quantitation ranged between 0.3 and 2.1 ng/μL for all analytes in the liquid matrix (CSF), while the respective values were in the range of 0.3-3.6 ng/mg for solid matrices (hair and nail clippings), with an injection volume of 20 μL. Repeatability and intermediate precision (relative standard deviation, RSD%) were less than 16.6%. The method was successfully applied to actual hair and nail samples from a patient under fluoxetine treatment., (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2012
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39. Evaluation of 5-methyl-2'-deoxycytidine stability in hydrolyzed and nonhydrolyzed DNA by HPLC-UV.
- Author
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Kovatsi L, Fragou D, Samanidou V, Njau S, Kouidou S, and Bailey A
- Subjects
- Animals, Cattle, Chromatography, High Pressure Liquid methods, DNA Methylation, Epigenomics, Freezing, Humans, Hydrolysis, Regression Analysis, Solutions, Specimen Handling, Spectrophotometry, Ultraviolet, DNA chemistry, Deoxycytidine analogs & derivatives, Deoxycytidine analysis
- Abstract
Background: Although the determination of 5-methyl-2'-deoxycytidine (5-MedC) in various biological samples is gaining increasing scientific interest, there are no data available regarding its stability., Results: We have currently evaluated the stability of 5-MedC and 2'-deoxycytidine (dC) at -20°C, both in hydrolyzed and nonhydrolyzed calf thymus DNA (CT DNA), as well as following repetitive freeze-thaw cycles. HPLC-UV was used for the accurate determination of the two 2'-deoxynucleosides. Statistical evaluation of the results revealed that 5-MedC and dC were stable in hydrolyzed CT DNA for at least 7 days and in nonhydrolyzed CT DNA for at least 65 days, when these were stored at -20°C. Furthermore, both 2'-deoxynucleosides were stable for at least three repetitive freeze-thaw cycles., Conclusion: By using HPLC-UV, we have evaluated the stability of 5-MedC and dC under storage conditions and repetitive freeze-thaw cycles. Our results are informative about the way samples should be handled and stored in epigenetic studies.
- Published
- 2012
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40. Dendritic and spinal alterations of the spiny stellate cells of the human visual cortex during normal aging.
- Author
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Mavroudis I, Petrides F, Manani M, Theocharides C, Ciobica A, Padurariu M, Kiourexidou M, Njau S, Costa V, and Baloyannis S
- Subjects
- Adult, Aged, Aged, 80 and over, Aging pathology, Animals, Dendrites pathology, Humans, Macaca mulatta, Male, Middle Aged, Rats, Synapses pathology, Synapses physiology, Visual Cortex pathology, Aging physiology, Dendrites physiology, Visual Cortex cytology, Visual Cortex physiology
- Abstract
The visual cortex undergoes age related changes that have been studied mainly in rats Maccaca Mulata, and human beings. Despite the fact that there is no extensive neuronal loss in aged brains, a lot of important pathological changes are found in the morphology of the neurons. The present study describes the morphological alterations of the spiny stel-late cells of the human primary visual cortex during normal aging, using Golgi method, Golgi-Nissl staining and Nissl staining. Two types of spiny stellate cells have been studied. the first one located at layer 4Cβ and the second one located at layer 4Cβ. Even if some spiny stel-late cells retain high number of primary dendrites in the aged group there seems to be important spine loss, and extensive dendrite pathology. Age-related changes were more significant in spiny stellate cells of layer 4Cβ. Dendritic and spinal alterations described in the present study could explain the decline in visual functions during normal aging.
- Published
- 2012
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41. Launching the Greek forensic DNA database. The legal framework and arising ethical issues.
- Author
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Voultsos P, Njau S, Tairis N, Psaroulis D, and Kovatsi L
- Subjects
- Greece, Humans, DNA genetics, Databases, Genetic, Ethics, Forensic Genetics
- Abstract
Since the creation of the first national DNA database in Europe in 1995, many European countries have legislated laws for initiating and regulating their own databases. The Greek government legislated a law in 2008, by which the National DNA Database of Greece was founded and regulated. According to this law, only DNA profiles from convicted criminals were recorded. Nevertheless, a year later, in 2009, the law was amended to permit the creation of an expanded database including innocent people and children. Unfortunately, the new law is very vague in many aspects and does not respect the principle of proportionality. Therefore, according to our opinion, it will soon need to be re-amended. Furthermore, prior to legislating the new law, there was no debate with the community itself in order to clarify what system would best suit Greece and what the citizens would be willing to accept. We present the current legal framework in Greece, we highlight issues that need to be clarified and we discuss possible ethical issues that may arise., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2011
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42. Long-term safety and efficiency of endovascular repair in an adolescent patient with post-traumatic aortic pseudoaneurysm.
- Author
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Kovatsi L, Bintoudi A, Njau S, Vasiliadis N, and Tsitouridis I
- Published
- 2011
43. Disposable pipette extraction for gas chromatographic determination of codeine, morphine, and 6-monoacetylmorphine in vitreous humor.
- Author
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Kovatsi L, Rentifis K, Giannakis D, Njau S, and Samanidou V
- Subjects
- Autopsy, Chromatography, Gas, Codeine analysis, Diagnosis, Humans, Morphine analysis, Morphine Derivatives analysis, Codeine isolation & purification, Forensic Toxicology methods, Morphine isolation & purification, Morphine Derivatives isolation & purification, Solid Phase Extraction methods, Vitreous Body chemistry
- Abstract
The availability of a sensitive and rapid analytical method for the determination of opiates, and other substances of forensic interest, in a variety of biological specimens is of utmost importance to forensic laboratories. Solid-phase extraction is very popular in the pre-treatment of forensic samples. Nevertheless, a new approach, disposable pipette extraction (DPX), is gaining increasing interest in sample preparation. DPX has already been applied to the analysis of drugs of abuse in common biological matrices, such as urine and blood, but has not yet been evaluated on alternative biological samples, such as vitreous humor. The objective of this study was to evaluate the applicability of DPX on the analysis of opiates in vitreous humor. The currently developed method is fast, reliable, and easy to perform. The sensitivity, precision, and accuracy are satisfactory. Recoveries obtained are within the range of 72-91%, whereas the sample volume of vitreous humor required is only 100 μL., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2011
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44. Epigenetic mechanisms in metal toxicity.
- Author
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Fragou D, Fragou A, Kouidou S, Njau S, and Kovatsi L
- Subjects
- Animals, DNA Methylation drug effects, DNA Methylation genetics, Histones genetics, Humans, Epigenesis, Genetic drug effects, Metals, Heavy toxicity
- Abstract
The true understanding of epigenetics evolved over time as our knowledge on DNA methylation and chromatin modifications and their effects on gene expression increased. The current flurry of research on epigenetics and the increasing documentation of the effects of various environmental factors on DNA methylation, chromatin modification, as well as on the expression of small non-coding RNAs (ncRNAs) have expanded the scope of research on the etiology of various diseases including cancer. The current review briefly discusses various molecular mechanisms of epigenetic regulation of gene expression, and expands the discussion with examples of heavy metal-induced alterations of gene expression and the associated epigenetic changes.
- Published
- 2011
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45. Isoprostane as a marker of oxidative stress in chronic heroin users: correlation with duration of heroin use or concomitant hepatitis C infection.
- Author
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Kovatsi L, Njau S, Nikolaou K, Tsolakidou A, Karamouzis I, and Thisiadou K
- Subjects
- Adult, Biomarkers blood, Case-Control Studies, Chronic Disease, Hepatitis C blood, Hepatitis C Antibodies blood, Heroin Dependence blood, Humans, Male, Time Factors, F2-Isoprostanes blood, Hepatitis C complications, Heroin Dependence complications, Oxidative Stress
- Abstract
Background: Although chronic heroin abuse has been extensively linked to oxidative stress, and while plasma 15-F(2t)-IsoP is considered a good indicator of oxidative stress, there remain few references in the literature about the plasma concentration of this marker in heroin dependent subjects., Objectives: To determine plasma 15-F(2t)-IsoP, as a marker of oxidative stress, in chronic heroin users, and to examine whether the values of this marker correlate with the duration of heroin use or with the presence of anti-HCV antibodies., Methods: Forty-two chronic heroin users and twenty two healthy control subjects were recruited for this study. An enzyme-immunoassay method was used for the determination of 15-F(2t)-IsoP in plasma., Results: Plasma 15-F(2t)-IsoP values were significantly higher in chronic heroin users compared to healthy controls. No correlation was found between the values of plasma 15-F(2t)-IsoP and the duration of heroin use. Heroin dependent subjects positive for anti-HCV antibodies had significantly lower values of plasma 15-F(2t)-IsoP as compared to those without a history of HCV infection., Conclusions: The elevated plasma 15-F(2t)-IsoP values in heroin dependent subjects, compared to healthy individuals, indicate a shift of the balance between oxidants and antioxidants towards the former and suggest that heroin dependent subjects could benefit from an antioxidant therapy.
- Published
- 2010
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46. Multiple variations in the branching pattern of the abdominal aorta.
- Author
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Raikos A, Paraskevas GK, Natsis K, Tzikas A, and Njau SN
- Subjects
- Cadaver, Humans, Male, Middle Aged, Aorta, Abdominal abnormalities
- Abstract
We report on a unique clinically and surgically significant case of multiple abdominal aorta variations. Specifically, the left inferior phrenic, left gastric and splenic artery arose in common from the left aspect of the aorta constituting a common phrenogastrosplenic trunk, while the common hepatic artery originated separately from the midline of the anterior aspect of the aorta just inferiorly to the trunk. An accessory right hepatic artery arises from the right-anterior aspect of the abdominal aorta adjacent to superior mesenteric artery origin. On the left side, two renal arteries were observed. Moreover, the left gonadal artery exhibited a high origin, arising inferiorly to the upper left renal artery. We discuss about the embryological development of abdominal aorta arterial abnormalities and we attempt to sort the noticed variations according to existing classification in the literature. It is highlighted that the thorough knowledge of these arterial variations is important for the success of upper abdomen surgical operations such as liver and kidney transplantation, kidney preservation, abdominal aorta related vascular surgery, treatment of hepatocellular carcinoma by transcatheter arterial chemoembolizations as well as imaging interpretation of the region. Preoperative selective angiography or other abdominal aorta imaging studies are helpful for arterial variation demonstration and a precious tool for appropriate surgery planning.
- Published
- 2010
47. DNA repair enables sex identification in genetic material from human teeth.
- Author
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Kovatsi L, Nikou D, Triantaphyllou S, Njau SN, Voutsaki S, and Kouidou S
- Abstract
Background: The purpose of this study was to test the effectiveness of a DNA repair protocol in improving genetic testing in compromised samples, frequently encountered in Forensic Medicine., Methods: In order to stretch the experiment conditions to the limits, as far as quality of samples and DNA is concerned, we tried the repair protocol on ten ancient human teeth obtained from an equal number of skeletons from a burial site in Lerna, Middle Helladic Greece (2100-1700 BC). For these samples, sex was previously determined morphologically, serving as a reference to compare our molecular data with. The samples were analysed using the DNA amelogenin sex test assay prior and after DNA polymerase repair. For every individual, two molecular sex determinations were obtained by visualising PCR products on an agarose gel., Results: DNA repair enabled genetic testing in these samples. Successful amplification of the amelogenin gene was obtained only from the repaired DNA in eight out of ten samples. Prior to the repair treatment, none of these samples yielded any PCR products, thus attesting to the authenticity of the amplified sequence. The concordance between morphological and molecular analysis was in reasonable agreement (71%)., Conclusions: These results reveal the impact of the repair process in studying single copy genes from low quality DNA. This protocol could facilitate molecular analysis in compromised samples, encountered in forensic medicine, as well as enable genetic studies in ancient remnants.
- Published
- 2009
48. Adult sudden death caused by aspiration of chewing gum.
- Author
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Njau SN
- Subjects
- Adult, Eosinophils pathology, Exudates and Transudates, Foreign Bodies pathology, Humans, Male, Pulmonary Atelectasis pathology, Pulmonary Emphysema pathology, Trachea pathology, Airway Obstruction etiology, Chewing Gum adverse effects, Death, Sudden etiology, Inhalation
- Abstract
A case of a fatal foreign material aspiration is presented in the following text. A 24-year-old white male died suddenly. A piece of chewing gum lodged in a pool of frothy fluid was revealed at autopsy. Microscopic examinations revealed atelectasia emphysema, eosinophilic exudate and empty spaces. Blood and urine samples were analyzed, for alcohol and drug use by fluorescence polarization immunoassay (FPIA) on an Abbott AXSYM system. No alcohol or other drugs were detected in blood or urine.
- Published
- 2004
- Full Text
- View/download PDF
49. Amphetamine derivative related deaths in northern Greece.
- Author
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Raikos N, Tsoukali H, Psaroulis D, Vassiliadis N, Tsoungas M, and Njau SN
- Subjects
- Adult, Greece epidemiology, Humans, Male, Middle Aged, Substance-Related Disorders epidemiology, Substance-Related Disorders pathology, Amphetamines poisoning, Forensic Medicine, Substance-Related Disorders mortality
- Abstract
Until 1997, only one amphetamine related derivatives (AMPs) fatality had been reported in Greece. Since then, amphetamine (AMP) or AMPs have been found in seven out of 1,500 post-mortem toxicological cases. The cause and manner of death of these seven cases were: 3,4-methylenedioxy-N-methamphetamine (MDMA) and 3,4-methylenedioxy-N-ethylamphetamine (MDEA) poisoning (n = 1), drowning in water (n = 4), cranial injuries caused by a traffic accident (n = 1) and heart failure (n = 1). In the case where the use of AMP or AMPs was considered, the immediate cause of death post-mortem toxicological analysis revealed 2 microg/ml MDMA and 0.7 microg/ml MDEA in blood. MDMA was identified in two cases of drowning (2 microg/ml in blood in the first case and 1.7 microg/g in liver in the second case) and in the traffic accident case (0.4 microg/g in liver). Methamphetamine was detected in two cases of drowning (2.5 microg/ml in blood in the first case and 6 microg/g in liver in the second case). AMP was found in the heart failure case (0.2 microg/g in liver). Alcohol was present, together with AMP or AMPs, in four cases. These findings indicate an increase in the illegal abuse of AMPs in Greece. Because of this, we now routinely screen for AMPs.
- Published
- 2002
- Full Text
- View/download PDF
50. Bioequivalence of two tablet formulations of atenolol after single oral administration in healthy volunteers.
- Author
-
Niopas I, Daftsios AC, Xanthakis I, Nikolaidis N, and Njau SN
- Subjects
- Adolescent, Adrenergic beta-Antagonists administration & dosage, Adrenergic beta-Antagonists blood, Adult, Area Under Curve, Atenolol administration & dosage, Atenolol blood, Chromatography, High Pressure Liquid, Cross-Over Studies, Half-Life, Humans, Middle Aged, Therapeutic Equivalency, Adrenergic beta-Antagonists pharmacokinetics, Atenolol pharmacokinetics
- Abstract
The pharmacokinetic parameters of two oral formulations of 100 mg tablets of atenolol (CAS 29122-68-7; Azectol as test and another commercially available preparation as reference) were compared in an open-label, randomized, single oral dose, two-period cross-over design to 17 healthy volunteers under fasting conditions. Serial blood samples were collected prior to each administration and at 17 points within 36 h after dosing. Plasma concentrations of atenolol were measured by a validated HPLC assay with fluorometric detection. The parametric 90% confidence intervals of the geometric mean values of the test/reference ratios were 94.4% to 112.9% (point estimate: 103%) for AUC0-infinity, 93.7% to 112.8% (point estimate: 103%) for AUC0-36, and 88.3% to 112.1% (point estimate: 100%) for Cmax, within the acceptance criteria for bioequivalence (80%-125%). Tmax values were analyzed by the nonparametric Wilcoxon test and the difference was not statistically significant. Therefore, it is concluded that the test and reference atenolol formulations are bioequivalent for both the extent and the rate of absorption.
- Published
- 2000
- Full Text
- View/download PDF
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