Subversion and Transcendence in the Latin American Modern Travel Novel (1928-1976)

The focus of this dissertation is the role that travel plays in Latin American novels that stem from 1928 to 1976, specifically, Macunaíma, Los pasos perdidos, El reino de este mundo, and Mascaró, el cazador americano. Departing from the fact that this period of time in history was marked by political and cultural change and upheaval, different aspects and interpretations of travel as manifested in the novels of the corpus are explored as a means of subversion and transcendence to hegemonic discourses. Travel is viewed as a means of disruption, particularly of limits and borders, be they geographical, political, and cultural. The idea of a heightened sense of potentiality inherent in travel is also explored as part of the subversive and transcendent nature of travel. The beginning of the work delves into alternative spaces that are created by voyage. These spaces are described as differential spaces using Lefebvre’s definition of the term. Following a discussion of space, myth in travel is explained as an open system that resists particular power structures. Travel’s role in disseminating myths is also studied. Subsequently, the function of the Trickster as a mythological figure and as a peripatetic storyteller is analyzed. The final aspect considered in this study is the creation and the use of alternative semiotic systems that exist inside and outside of travel that subvert and transcend authoritative discourses of power

Analyzing AI Translation Through the Lens of Foucault’s L’archeologie du savoir

Exploring language and AI through the lens of Foucault's L'archeologie du savoir

The Role of Sodium in Diabetic Cardiomyopathy

Cardiovascular complications are the major cause of mortality and morbidity in diabetic patients. The changes in myocardial structure and function associated with diabetes are collectively called diabetic cardiomyopathy. Numerous molecular mechanisms have been proposed that could contribute to the development of diabetic cardiomyopathy and have been studied in various animal models of type 1 or type 2 diabetes. The current review focuses on the role of sodium (Na+) in diabetic cardiomyopathy and provides unique data on the linkage between Na+ flux and energy metabolism, studied with non-invasive 23Na, and 31P-NMR spectroscopy, polarography, and mass spectroscopy. 23Na NMR studies allow determination of the intracellular and extracellular Na+ pools by splitting the total Na+ peak into two resonances after the addition of a shift reagent to the perfusate. Using this technology, we found that intracellular Na+ is approximately two times higher in diabetic cardiomyocytes than in control possibly due to combined changes in the activity of Na+–K+ pump, Na+/H+ exchanger 1 (NHE1) and Na+-glucose cotransporter. We hypothesized that the increase in Na+ activates the mitochondrial membrane Na+/Ca2+ exchanger, which leads to a loss of intramitochondrial Ca2+, with a subsequent alteration in mitochondrial bioenergetics and function. Using isolated mitochondria, we showed that the addition of Na+ (1–10 mM) led to a dose-dependent decrease in oxidative phosphorylation and that this effect was reversed by providing extramitochondrial Ca2+ or by inhibiting the mitochondrial Na+/Ca2+ exchanger with diltiazem. Similar experiments with 31P-NMR in isolated superfused mitochondria embedded in agarose beads showed that Na+ (3–30 mM) led to significantly decreased ATP levels and that this effect was stronger in diabetic rats. These data suggest that in diabetic cardiomyocytes, increased Na+ leads to abnormalities in oxidative phosphorylation and a subsequent decrease in ATP levels. In support of these data, using 31P-NMR, we showed that the baseline β-ATP and phosphocreatine (PCr) were lower in diabetic cardiomyocytes than in control, suggesting that diabetic cardiomyocytes have depressed bioenergetic function. Thus, both altered intracellular Na+ levels and bioenergetics and their interactions may significantly contribute to the pathology of diabetic cardiomyopathy

Application of 23Na MRI to Monitor Chemotherapeutic Response in RIF-1 Tumors

Effects of an alkylating anticancer drug, cyclophosphamide (Cp), on 23Na signal intensity (23Na SI) and water apparent diffusion coefficient (ADC) were examined in subcutaneously - implanted radiation-induced fibrosarcoma (RIF-1) tumors by in vivo23Na and 1H magnetic resonance imaging (MRI). MRI experiments were performed on untreated control (n = 5) and Cp-treated (n = 6) C3H mice, once before Cp injection (300 mg/kg) then daily for 3 days after treatment. Tumor volumes were significantly lower in treated animals 2 and 3 days posttreatment. At the same time points, MRI experiments showed an increase in both 23Na SI and water ADC in treated tumors, whereas control tumors did not show any significant changes. The correlation between 23Na SI and water ADC changes was dramatically increased in the Cp-treated group, suggesting that the observed increases in 23Na SI and water ADC were caused by the same mechanism. Histologic sections showed decreased cell density in the regions of increased 23Na and water ADC SI. Destructive chemical analysis showed that Cp treatment increased the relative extracellular space and tumor [Na+]. We conclude that the changes in water ADC and 23Na SI were largely due to an increase in extracellular space. 23Na MRI and 1H water ADC measurements may provide valuable noninvasive techniques for monitoring chemotherapeutic responses

Uncoupled respiration stability of isolated pancreatic acini as a novel functional test for cell vitality

Background. Assessment of cell viability is crucial in cell studies. Testing plasma membrane integrity is a traditional approach of evaluating cell viability. Mitochondrial functional capacity closely correlates with plasma membrane integrity and overall cell health. This study aimed to investigate whether any aspect of mitochondrial adaptive capacity in isolated pancreatic acini is associated with the quality of isolated pancreatic acini preparations, as determined by the dye exclusion method. Materials and Methods. Experiments were carried out on male Wistar rats weig­hing 250–300 g. A suspension of isolated pancreatic acini was obtained using collagenase. The rate of oxygen consumption of rat isolated pancreatic acini was measured with Clark oxygen electrode. Basal respiration of isolated pancreatic acini was recorded for approximately 2 min. Afterwards, the mitochondrial adaptive capacity was examined using FCCP in concentrations from 0.5 to 2 μM. Uncoupled respiratory stability was calculated as a ratio of respiration rate at high and low FCCP concentrations. Plasma membrane integrity was assessed with trypan blue staining. A total of 74 preparations of isolated pancreatic acini were used in this study. Results. In all experiments, 92–99 % of pancreatic acinar cells exhibited negative trypan blue staining, indicating intact plasma membranes. The basal and maximal uncoupled respiration rates were not affected by the fraction of trypan-negative cells. However, acini preparations with <less than 95 % plasma membrane integrity had significantly lower uncoupled respiration rates when exposed to a high concentration of FCCP (2 µM), indicating reduced stability of uncoupled respiration. Conclusions. Results of the study suggest that the stability of uncoupled respiration can serve as a novel metabolic functional test to complement the existing methods for assessing cell vitality

Antineoplastic activity of novel thiazole derivatives

The development of novel efficient substances for anticancer chemotherapy is an important problem of medicinal chemistry. Aim. To evaluate the level of cytotoxic action of novel thiazole derivatives towards tumor cell lines of different origin. Methods. Four N acylated 2-amino-5-benzyl-1,3-thiazoles (5a–d) were synthesized by reaction of 2-amino-5-R-benzyl-1,3-thiazoles with acid chlorides in the presence of triethylamine in the dioxane medium. Anticancer screening of the synthesized thiazoles was performed by the MTT assay. Results. Thiazole derivatives were shown to exert antineoplastic activity towards different types of tumor cells. The anti-glioma and anti-melanoma selectivity of these derivatives action was demonstrated. The compound 5a was found to be the most toxic for human glioblastoma U251 cells and human melanoma WM793 cells. At the same time, the created compounds possessed low toxicity towards pseudo-normal cells. Conclusion. The novel thiazole derivative 5a was the most toxic against human glioblastoma and melanoma cells.Створення нових ефективних субстанцій для використання у протипухлинній хіміотерапії є актуальним напрямком медичної хімії. Мета. Дослідити цитотоксичну дію нових похідних тіазолу щодо пухлинних клітин різного тканинного походження. Мето-ди. Чо-ти-ри нові N-ацильованих 2-аміно-5-бензил-1,3-тіазолів (субстанції 5a‑d) були синтезовані взаємодією 2-аміно-5-R-бензил-1,3-тіазолів з ацилхлоридами у середовищі діоксану за наявності триетиламіну. Для дослідження протипухлинної активності похідних тіазолу використовували МТТ-тест. Результа-ти. Вста-новлено, що деякі похідні тіазолу мають антинеопластичну активність щодо пухлинних клітин різного тканинного походження. Показано селективну антигліомну та антимеланомну дію досліджуваних сполук. Речовина 5а має найбільш виражену цитотоксичну дію щодо клітин лінії U251 гліобластоми людини і лінії WM793 меланоми людини. Синтезовані сполуки мають низьку токсичність щодо псевдонормальних ембріональних клітин нирки. Висновок. Нове похідне тіазолу (речовина 5а) є перспективним цитотоксичним чинником для дії на клітини гліобластоми і меланоми.Разработка и синтез новых производных тиазола являются перспективным направлением медицинской химии и противоопухолевой терапии. Цель. Изучение цитотоксического действия новых производных тиазола в отноше-нии злокачественных клеток различного тканевого происхождения. Методы. Четыре новых N-ацилированных 2-амино-5-бензил-1,3-тиазола (5a–d) были синтезированы взаимодействием 2-амино-5-R-бензил-1,3-тиазолов с ацилхлоридами в присутствии триэтиламина в среде диоксана. Исследование противоопухолевой активности тиа-золов проводили с использованием МТТ-анализа. Результаты. Уста-нов-лено, что производные тиазола оказывают противоопухолевое действие на некоторые типы опухолей. Было подтверждено селективное антиглиомное и ан-тимеланомное действие соединений. Соединение 5а проявляет наиболее выраженное цитотоксическое действие на опухолевые клетки U251 глиобластомы человека и WM793 меланомы человека. Исследованные соединения обла-дают низкой токсичностью по отношению к псевдо-нормальным эмбриональным клеткам почек. Вывод. Соедине-ние 5а является перспективным токсическим агентом для клеток глиобластомы и меланомы

Genotoxicity and acute toxicity of 2-amino-5-benzylthiazole in complex with polymeric nanocarrier in Allium bioassay

Background. The search for optimal methods of selective and integral determination of various cytotoxic compounds in biological fluids and tissues, which would have high sensitivity and allow for quick and reliable assessment and detection of potentially cytotoxic components of substances with biologically active action, remains relevant today. It is known that chemotherapeutic agents can be released into the environment (air, surface water, sediments and soil) and cause adverse consequences (impact on the stability of ecosystems due to reduced viability of species). The aim of this work was to investigate the effect of thiazole derivative N-(5-benzyl-1,3-thiazol-2-yl)-3,5-dimethyl1-benzofuran-2-carboxamide (BF1) conjugated with PEG-based polymeric nanoparticles (PEG-PN – Th1) on genotoxicity and acute toxicity in allium bioassay. Materials and Methods. Allium cepa ana-telophase assay was applied to monitor genotoxicity of the studied compounds. The acute toxic effects such as inhibition of cell division, seed germination and growth of Allium roots were estimated. A. cepa seeds (15 per each point) were germinated on the studied solutions of BF1, Th1 and Th2 (10 μM) for 5 days at 22 °C. The root growth and the percentage of inhibition of seed germination were calculated. In order to establish cyto- and genotoxicity of the studied compounds, we have determined the mitotic index and the relative amount of chromosomal aberrations. Results. BF1 had a significant inhibitory effect on root growth and seed germination at a concentration of 10 μM. The effect was eliminated when it was influenced by BF1 complex with a polymeric carrier. The free polymer does not have a negative effect on the studied parameters either. A significant decrease in the mitotic index and increase in the percentage of chromosomal aberrations was observed under the action of BF1 at a concentration of 10 µM. There was no significant change in the value of mitoitic index and percentage of chromosomal aberrations under the action of Th2 comp­lex or polymeric carrier Th1. Conclusions. The thiazole derivative in complex with a polymeric carrier at a concentration of 10 µM did not show acute toxicity in Allium cepa bioassay. Polymer carrier based on polyethylene glycol neutralized the negative effect of BF1 on the mitotic and phase indices of Allium root meristem cells; it also decreased the percentage of chromosomal aberrations

Proton and sodium MRI assessment of emerging tumor chemotherapeutic resistance

The ultimate goal of any cancer therapy is to target the elimination of neoplastic cells. Although newer therapeutic strategies are in constant development, therapeutic assessment has been hampered by the inability to assess, rapidly and quantitatively, efficacy in vivo . Diffusion imaging and, more recently, sodium MRI have demonstrated their distinct abilities to detect therapy-induced alterations in tumor cellularity, which has been demonstrated to be indicative of therapeutic efficacy. More importantly, both imaging modalities detect tumor response much earlier than traditional methodologies that rely on macroscopic volumetric changes. In this study, the correlation between tumor sodium and diffusion was further tested to demonstrate the sensitivity of sodium imaging to gauge tumor response to therapy by using a 9L rat gliosarcoma treated with varying doses of BCNU [1,3-bis(2-chloroethyl)-1-nitrosourea]. This orthotopic model has been demonstrated to display variability in response to BCNU therapy where initial insult has been shown to lead to drug-resistance. In brief, a single 26.6 mg/kg BCNU dose yielded dramatic responses in both diffusion and sodium MRI. However, a second equivalent BCNU dose yielded a much smaller change in diffusion and sodium, suggesting a drop in tumor sensitivity to BCNU. The MRI responses of animals treated with 13.3 mg/kg BCNU were much lower and similar responses were observed after the initial and secondary applications of BCNU. Furthermore, these results were further validated using volumetric measurements of the tumor and also ex vivo determination of tumor sensitivity to BCNU. Overall, these experiments demonstrate the sensitivity and applicability of sodium and diffusion MRI as tools for dynamic assessment of tumor response to therapy. Copyright © 2006 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55899/1/1074_ftp.pd

Multiple quantum filtered ²³Na NMR in the Langendorff perfused mouse heart:Ratio of triple/double quantum filtered signals correlate with [Na]_i

AbstractWe investigate the potential of multiple quantum filtered (MQF) 23Na NMR to probe intracellular [Na]i in the Langendorff perfused mouse heart. In the presence of Tm(DOTP) shift reagent the triple quantum filtered (TQF) signal originated largely from the intracellular sodium pool with a 32±6% contribution of the total TQF signal arising from extracellular sodium, whilst the rank 2 double-quantum filtered signal (DQF), acquired with a 54.7° flip-angle pulse, originated exclusively from the extracellular sodium pool. Given the different cellular origins of the 23Na MQF signals we propose that the TQF/DQF ratio can be used as a semi-quantitative measure of [Na]i in the mouse heart. We demonstrate a good correlation of this ratio with [Na]i measured with shift reagent at baseline and under conditions of elevated [Na]i. We compare the measurements of [Na]i using both shift reagent and TQF/DQF ratio in a cohort of wild type mouse hearts and in a transgenic PLM3SA mouse expressing a non-phosphorylatable form of phospholemman, showing a modest but measurable elevation of baseline [Na]i. MQF filtered 23Na NMR is a potentially useful tool for studying normal and pathophysiological changes in [Na]i, particularly in transgenic mouse models with altered Na regulation

Apoptosis induction in human leukemia cells by novel 2-amino-5-benzylthiazole derivatives

Derivatives of 2-amino-5-benzylthiazole are heterocyclic pharmacophores that exhibit different pharmacological activities including anticancer action. The mechanisms of such action of these compounds are not clear. The aim of the present study was to investigate apoptosis induction, particularly DNA damage in human leukemia cells, by the novel synthesized thiazole derivatives ‒ 2,8-dimethyl-7-(3-trifluoromethyl-benzyl)pyrazolo[4,3-e]thiazolo[3,2-a]pyrimidin-4(2H)-one (compound 1) and 7-benzyl-8-methyl-2-propylpyrazolo[4,3-e]thiazolo[3,2-a]pyrimidin-4(2H)-one (compound 2). Western-blot analysis, DNA comet assay in alkaline conditions, diphenylamine DNA fragmentation assay, agarose gel retardation, and methyl green DNA intercalation assays were used to study the effects of the studied compounds in human leukemia cells. These compounds induced PARP1 and caspase 3 cleavage in the leukemia cells, also increased the level of pro-apoptotic Bim protein and the mitochondrion-specific EndoG nuclease, and decreased the level of the anti-apoptotic Bcl-2 protein. They caused DNA single-strand breaks and DNA fragmentation in the leukemia cells without direct DNA binding or DNA intercalation. Thus, novel 2-amino-5-benzylthiazole derivatives may be promising agents for apoptosis induction in the targeted human leukemia cells