scholarly journals A comparative study of the effects of methamphetamine on memory in existing and recovering addicts from a South African population

2012 ◽  
Vol 17 (1) ◽  
Author(s):  
Cindy Van Wyk ◽  
Anita D. Stuart

Memory is a complex of systems by which an organism registers, stores and retrieves exposure to an event or experience. Literature purports that methamphetamine users and dependents have been found to exhibits signs of memory impairment. The aim of the research was to establish the possible existence of significant differences in memory in current methamphetamine users, recovering methamphetamine users, and a matched drug naïve control group. Cognitive functioning was assessed via a neurocognitive test battery that examined the memory of 14 current methamphetamine users, 17 recovering methamphetamine addicts, and 18 drug naïve control participants who were matched according to the demographic variables of age, gender and educational status. The results indicated that recovering methamphetamine users experienced the greatest impairment in memory in comparison to both the control group and current users of methamphetamine. The current users of methamphetamine also experienced some impairment in memory functioning in visual acquisition and retention. The poor performance of the recovering addicts is explained by the juxtaposition of the stimulating and supplemental effect of methamphetamine as experienced by the current users versus the neurotransmitter depletion and structural changes in the brain experienced by the recovering addicts. The control group showed a superior performance since they did not suffer from the neurotoxic effects of methamphetamine.OpsommingGeheue is ‘n komplekse sisteem wat ‘n individu in staat stel om blootstelling aan ‘n voorval of ervarings te registreer, stoor, behou en herroep. Leer- en geheueprobleme is van die mees algemene simptome van neurosielkundige uitvalle in neurologiese en psigiatriese pasiënte. Die literatuur dui aan dat metamfetamienafhanklike verbruikers tipies geheuedisfunksie ervaar. Die doel van die navorsing was om die moontlike voorkoms van verskille in geheuefunksie in huidige gebruikers van metamfetamien, rehabiliterende gebruikers, sowel as ‘n kontrolegroep van dwelmmiddel-naïewe demografies-passende individue te bepaal. Uitvoerende funksie is gemeet met ‘n neurokognitiewe toetsbattery wat die geheuefunksies van 14 huidige gebruikers van metamfetamien, 17 rehabiliterende metamfetamienverslaafde individue en 18 dwelmmiddel-naïewe deelnemers, gepas in terme van ouderdom, geslag en opvoedkundige status, bepaal het. Die resultate dui aan dat dat die rehabiliterende metamfetamiengebruikers die grootste geheueuitvalle getoon het in vergelyking met sowel die huidige gebruikers as die kontrolegroep. Die huidige metamfetamiengebruikers het ook matige geheueuitvalle getoon, spesifiek in visuele leer en retensie. Dit is moontlik dat die geheueuitvalle wat deur metamfetamiengebruikers ervaar word, verband hou met strukturele en funksionele verandering in die breingebiede wat met geheue geassosieer word, as gevolg van metamfetamienvergiftiging. Die swak prestasie van die rehabiliterende metamfetamienverslaafde persone in vergelyking met die huidige gebruikers word verduidelik in terme van die naasmekaarstelling van die stimulerende en aanvullende effek van metamfetamien soos ervaar deur die huidige gebruikers versus die neurotransmitteruitputting en strukturele breinveranderinge in die rehabiliterende individue. Die kontrolegroep het ‘n beter resultaat getoon omdat hulle geen neurotoksiese effekte van metamfetamien gehad het nie. 

2011 ◽  
pp. 119-125
Author(s):  
Thi Thuy Hang Nguyen

Objective: Prehypertensive individuals are at increased risk for developing hypertension and their complication. Many studies show that 2/3 prehypertensive individuals develop hypertension after 4 years. ECG and echocardiography are the routine tests used to assess LV mass. The objective of the research to determine the percentage of change in left ventricular morphology in the ECG, echocardiography, which explore the characteristics of left ventricular structural changes by echocardiography in pre-hypertensive subjects. Materials and method: We studied a total of 50 prehypertensive, 30 males (60%) and 20 females (40%), mean age 48.20±8.47years. 50 normotensive volunteers as control participants. These subjects were examined for ECG and echocardiography. Results: In prehypertensive group, with 18% of left ventricular hypertrophy on electrocardiogram, 12% of left ventricular hypertrophy on echocardiography; in the control group, we did not find any subjects with left ventricular hypertrophy. In the group with left ventricular hypertrophy, mostly eccentric left ventricular hypertrophy (83.33%), concentric left ventricular hypertrophy is 16.67%. Restructuring of left ventricular concentric for 15.9% of subjects without left ventricular hypertrophy on echocardiography. Conclusion: There have been changed in left ventricular morphology even in prehypertensive


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Chu-nan Zhang ◽  
Lin-yi Zhou ◽  
Shu-jiao Qian ◽  
Ying-xin Gu ◽  
Jun-yu Shi ◽  
...  

Abstract Objectives This study aims to evaluate the ability of tantalum-coated titanium to improve human gingival fibroblasts’ adhesion, viability, proliferation, migration performance, and the potential molecular mechanisms. Materials and methods Titanium plates were divided into two groups: (1) no coating (Ti, control), (2) Tantalum-coated titanium (Ta-coated Ti). All samples were characterized by scanning electronic microscopy, surface roughness, and hydrophilicity. Fibroblasts’ performance were analyzed by attached cell number at 1 h, 4 h, and 24 h, morphology at 1 h and 4 h, viability at 1 day, 3 days, 5 days, and 7 days, recovery after wounding at 6 h, 12 h, and 24 h. RT-PCR, western blot were applied to detect attachment-related genes’ expression and protein synthesis at 4 h and 24 h. Student’s t test was used for statistical analysis. Results Tantalum-coated titanium demonstrates a layer of homogeneously distributed nano-grains with mean diameter of 25.98 (± 14.75) nm. It was found that after tantalum deposition, human gingival fibroblasts (HGFs) adhesion, viability, proliferation, and migration were promoted in comparison to the control group. An upregulated level of Integrin β1 and FAK signaling was also detected, which might be the underlying mechanism. Conclusion In the present study, adhesion, viability, proliferation, migration of human gingival fibroblasts are promoted on tantalum-coated titanium, upregulated integrin β1 and FAK might contribute to its superior performance, indicating tantalum coating can be applied in transmucosal part of dental implant. Clinical significance Tantalum deposition on titanium surfaces can promote human gingival fibroblast adhesion, accordingly forming a well-organized soft tissue sealing and may contribute to a successful osseointegration.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1602
Author(s):  
Anna Elizarova ◽  
Alexey Sokolov ◽  
Valeria Kostevich ◽  
Ekaterina Kisseleva ◽  
Evgeny Zelenskiy ◽  
...  

As shown recently, oleic acid (OA) in complex with lactoferrin (LF) causes the death of cancer cells, but no mechanism(s) of that toxicity have been disclosed. In this study, constitutive parameters of the antitumor effect of LF/OA complex were explored. Complex LF/OA was prepared by titrating recombinant human LF with OA. Spectral analysis was used to assess possible structural changes of LF within its complex with OA. Structural features of apo-LF did not change within the complex LF:OA = 1:8, which was toxic for hepatoma 22a cells. Cytotoxicity of the complex LF:OA = 1:8 was tested in cultured hepatoma 22a cells and in fresh erythrocytes. Its anticancer activity was tested in mice carrying hepatoma 22a. In mice injected daily with LF-8OA, the same tumor grew significantly slower. In 20% of animals, the tumors completely resolved. LF alone was less efficient, i.e., the tumor growth index was 0.14 for LF-8OA and 0.63 for LF as compared with 1.0 in the control animals. The results of testing from 48 days after the tumor inoculation showed that the survival rate among LF-8OA-treated animals was 70%, contrary to 0% rate in the control group and among the LF-treated mice. Our data allow us to regard the complex of LF and OA as a promising tool for cancer treatment.


Mathematics ◽  
2021 ◽  
Vol 9 (15) ◽  
pp. 1832
Author(s):  
Mariano Méndez-Suárez

Partial least squares structural equations modeling (PLS-SEM) uses sampling bootstrapping to calculate the significance of the model parameter estimates (e.g., path coefficients and outer loadings). However, when data are time series, as in marketing mix modeling, sampling bootstrapping shows inconsistencies that arise because the series has an autocorrelation structure and contains seasonal events, such as Christmas or Black Friday, especially in multichannel retailing, making the significance analysis of the PLS-SEM model unreliable. The alternative proposed in this research uses maximum entropy bootstrapping (meboot), a technique specifically designed for time series, which maintains the autocorrelation structure and preserves the occurrence over time of seasonal events or structural changes that occurred in the original series in the bootstrapped series. The results showed that meboot had superior performance than sampling bootstrapping in terms of the coherence of the bootstrapped data and the quality of the significance analysis.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sarv Priya ◽  
Tanya Aggarwal ◽  
Caitlin Ward ◽  
Girish Bathla ◽  
Mathews Jacob ◽  
...  

AbstractSide experiments are performed on radiomics models to improve their reproducibility. We measure the impact of myocardial masks, radiomic side experiments and data augmentation for information transfer (DAFIT) approach to differentiate patients with and without pulmonary hypertension (PH) using cardiac MRI (CMRI) derived radiomics. Feature extraction was performed from the left ventricle (LV) and right ventricle (RV) myocardial masks using CMRI in 82 patients (42 PH and 40 controls). Various side study experiments were evaluated: Original data without and with intraclass correlation (ICC) feature-filtering and DAFIT approach (without and with ICC feature-filtering). Multiple machine learning and feature selection strategies were evaluated. Primary analysis included all PH patients with subgroup analysis including PH patients with preserved LVEF (≥ 50%). For both primary and subgroup analysis, DAFIT approach without feature-filtering was the highest performer (AUC 0.957–0.958). ICC approaches showed poor performance compared to DAFIT approach. The performance of combined LV and RV masks was superior to individual masks alone. There was variation in top performing models across all approaches (AUC 0.862–0.958). DAFIT approach with features from combined LV and RV masks provide superior performance with poor performance of feature filtering approaches. Model performance varies based upon the feature selection and model combination.


Author(s):  
Nikita Sushentsev ◽  
Leonardo Rundo ◽  
Oleg Blyuss ◽  
Tatiana Nazarenko ◽  
Aleksandr Suvorov ◽  
...  

Abstract Objectives To compare the performance of the PRECISE scoring system against several MRI-derived delta-radiomics models for predicting histopathological prostate cancer (PCa) progression in patients on active surveillance (AS). Methods The study included AS patients with biopsy-proven PCa with a minimum follow-up of 2 years and at least one repeat targeted biopsy. Histopathological progression was defined as grade group progression from diagnostic biopsy. The control group included patients with both radiologically and histopathologically stable disease. PRECISE scores were applied prospectively by four uro-radiologists with 5–16 years’ experience. T2WI- and ADC-derived delta-radiomics features were computed using baseline and latest available MRI scans, with the predictive modelling performed using the parenclitic networks (PN), least absolute shrinkage and selection operator (LASSO) logistic regression, and random forests (RF) algorithms. Standard measures of discrimination and areas under the ROC curve (AUCs) were calculated, with AUCs compared using DeLong’s test. Results The study included 64 patients (27 progressors and 37 non-progressors) with a median follow-up of 46 months. PRECISE scores had the highest specificity (94.7%) and positive predictive value (90.9%), whilst RF had the highest sensitivity (92.6%) and negative predictive value (92.6%) for predicting disease progression. The AUC for PRECISE (84.4%) was non-significantly higher than AUCs of 81.5%, 78.0%, and 80.9% for PN, LASSO regression, and RF, respectively (p = 0.64, 0.43, and 0.57, respectively). No significant differences were observed between AUCs of the three delta-radiomics models (p-value range 0.34–0.77). Conclusions PRECISE and delta-radiomics models achieved comparably good performance for predicting PCa progression in AS patients. Key Points • The observed high specificity and PPV of PRECISE are complemented by the high sensitivity and NPV of delta-radiomics, suggesting a possible synergy between the two image assessment approaches. • The comparable performance of delta-radiomics to PRECISE scores applied by expert readers highlights the prospective use of the former as an objective and standardisable quantitative tool for MRI-guided AS follow-up. • The marginally superior performance of parenclitic networks compared to conventional machine learning algorithms warrants its further use in radiomics research.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5907 ◽  
Author(s):  
Marina Pidal-Miranda ◽  
Alberto Jacobo González-Villar ◽  
María Teresa Carrillo-de-la-Peña ◽  
Elena Andrade ◽  
Dolores Rodríguez-Salgado

BackgroundCognitive dysfunction in fibromyalgia (FM) encompasses objective cognitive difficulties, as measured in neuropsychological tests, and self-reported cognitive complaints. Although it has been suggested that FM patients display problems in working memory, the data are inconsistent, and the overall working memory status of the patients is unclear. It is also not clear whether the working memory problems are related to cognitive complaints or how the dyscognition is affected by the characteristic clinical symptoms of FM.MethodsTo clarify these aspects, we explored the neuropsychological performance for different components of working memory and the subjective self-perception of cognitive status in a sample of 38 women with FM. They were compared with a matched group of 32 healthy women.ResultsOur findings suggested that the FM patients do not differ from healthy controls in their overall working memory functioning. Only a poor performance was found in a single task of visuospatial working memory, mediated by the presence of depressive symptoms, fatigue and pain. The FM patients also displayed a higher level of perception of cognitive difficulties than healthy controls, and this difference was mediated by depression and fatigue. Furthermore, cognitive complaints in FM patients were only associated with a lower verbal WM capacity.DiscussionFM patients have a subtle specific impairment in their working memory functioning, as well as elevated concern about their cognitive status. These findings suggest a disconnection between neuropsychological performance and subjective complaints. In FM patients, clinical variables such as pain, fatigue, and depression play an important role in dyscognition, as assessed by both objective and subjective measures, and should be taken into account in future research.


2020 ◽  
Vol 9 (3) ◽  
pp. 185-197
Author(s):  
Pedro Arede ◽  
Joanna Przezdziecka-Dolyk ◽  
Fabian Debowy ◽  
Jacek Olszewski ◽  
Carla Fernandes ◽  
...  

Background: The aim of this study was to evaluate the characteristics of the macular vessel density (VD) and the foveal avascular zone (FAZ) in glaucoma quantitatively using the optical coherence tomography angiography (OCT-A). Methods: Twenty-five eyes of 13 patients with primary open angle glaucoma (POAG) and 12 eyes of 6 healthy participants were enrolled retrospectively. Functional visual field (VF) and structural Spectral-Domain optical coherence tomography (SD-OCT) Retinal Nerve Fiber Layer Thickness (RNFLT) were assessed in all participants. OCT-A was performed on a fovea centered, 15x10 degrees, macular region. OCT-A scans were processed with MATLAB software and automatically graded to define FAZ parameters. The parafoveal VD in the superficial and deep retinal vascular plexus (SVP and DVP) was analyzed by quadrant and circular segmented zones. Results: Foveal Avascular Zone -Major Axis Length (p=0.02), Area (p=0.04), Equivalent Diameter (p=0.04) and Perimeter (p=0.04) were significantly larger in glaucoma than the control group. Regarding SVP and DVP, the average macular total VD were lower in glaucoma patients compared to the control group (p<0.01; p<0.01). Additionally, the inner circular region (p=0.04; p<0.01 respectively for SVP and DVP) and all quadrants except for North had a lower VD in glaucoma group compared to the control group. Assessment of the total VD successfully predicted RNFLT (p<0.001) and was significantly associated with the probability of glaucoma (p=0.009). Conclusion: OCT-A parameters, namely the FAZ morphology and the macular VD, were associated with glaucomatous functional and structural changes. The macular VD showed a considerable diagnostic value. It may be a modern biomarker, representing microvascular network disruption of the macular perfusion in glaucoma.


2021 ◽  
Vol 27 (1) ◽  
pp. 68-73
Author(s):  
E.N. Shchurova ◽  
◽  
G.N. Filimonova ◽  
S.O. Ryabykh ◽  
◽  
...  

Introduction Morphological, biochemical and histopathological characteristics of paraspinal muscles have been well described in patients with idiopathic scoliosis. However, there is a paucity of literature on morphological picture of paraspinal muscles in patients with severe idiopathic scoliosis. Objective To explore how the magnitude of thoracic spine deformity affects morphological characteristics of paraspinal muscles in patients with severe idiopathic scoliosis. Material and methods A total 21 patients with idiopathic scoliosis were reviewed. The patients were assigned to two groups depending on magnitude of preoperative thoracic spine deformity. A major group consisted of patients with scoliosis of ≥ 60º (n = 11) and control group included patients with a curve < 60º (n=10). Biopsy samples were taken from muscle fragments (multifidus muscle) at the apex of the curve (major arc) at the Th6-Th10 level on the convex side while approaching to the posterior spinal structures during surgical correction of kyphoscoliosis using light microscope. The specimens were examined histologically with light microscope. Results Patients with severe idiopathic scoliosis (≥ 60º) showed evident muscle fiber atrophy and dystrophy of different extent. There were nucleus free areas and homogenized muscle fragments observed with connective tissue layers being swollen and frayed with multiple fibroblasts seen in nearly all the samples. Arterial walls were normally fibrotized. Structural changes ranged from minimal with a curve of 60º to degrading muscles with the fibers replaced by fat and connective tissues with a curve angle of 145º. Conclusion Morphological characteristics of paraspinal muscles have been shown to be severely affected by the magnitude of thoracic spine deformity in patients with severe idiopathic scoliosis. The findings should be considered in surgical correction of kyphoscoliosis with special focus on postoperative vascular and neurotropic therapy to allow wound healing and lower complication rate.


2020 ◽  
Vol 10 (5) ◽  
pp. 27-34
Author(s):  
Eugene V. Timofeev ◽  
Eduard G. Malev ◽  
Nina N. Parfenova ◽  
Eduard V. Zemtsovsky

For many hereditary connective tissue disorders (HCTD), especially Marfan syndrome, remodeling of the heart and main vessels is described, which is manifested by a decrease in the systolic function of the left ventricle and expansion of the thoracic aorta. Evaluation of morphometric characteristics of the heart and main vessels in patients with other HCTD, in particular marfanoid habitus (MH) has not been previously carried out. Materials and methods. Weexamined 90 young men and 74 young women between the ages of 18 to 25 years, 111 patients older age groups with stable over coronary heart disease (mean age 64.66.2 years) and 9 patients with verified Marfan syndrome (mean age 27.99.3years). All survey phenotypic and performed anthropometric survey identifying bone signs of dysembryogenesis as well as Echocardiography study on standard protocol. The results.Patients with MH as compared with control group revealed a relatively larger diameter of aortic root (30.44.7 vs 28.03.6 mm,p= 0.03) and the ascending aorta (26.64.9 vs 24.63.2 mm,p= 0.05). Also young with MH turned out to be significantly thicker myocardium of left ventricular posterior wall (8.30.8 vs 7.71.1 mm,p= 0.02) and interventricular septum (8.81.2vs 8.21.1mm,p= 0.04). When performing correlation analysis identified reliable positive correlation between such highly specialized bone signs as high palate (r= 0.31), infundibular deformation of the chest (r= 0.43), arachnodactyly (r= 0.45) andZ-test (p 0.05 for all). Expansion of the aorta (Z-criterion 2.0) have found 24% of older patients with MH. Conclusion.Inpatients with MH revealed significant structural changes of heart and main vessels which are progredient character thickening of the left ventricular myocardium and expansion of the aortic root.


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