472 research outputs found

    Dynamic specification of vowels in Hijazi Arabic

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    \ua9 2024 De Gruyter Mouton. All rights reserved.Research on various languages shows that dynamic approaches to vowel acoustics – in particular Vowel-Inherent Spectral Change (VISC) – can play a vital role in characterising and classifying monophthongal vowels compared with a static model. This study’s aim was to investigate whether dynamic cues also allow for better description and classification of the Hijazi Arabic (HA) vowel system, a phonological system based on both temporal and spectral distinctions. Along with static and dynamic F1 and F2 patterns, we evaluated the extent to which vowel duration, F0, and F3 contribute to increased/decreased discriminability among vowels. Data were collected from 20 native HA speakers (10 females and 10 males) producing eight HA monophthongal vowels in a word list with varied consonantal contexts. Results showed that dynamic cues provide further insights regarding HA vowels that are not normally gleaned from static measures alone. Using discriminant analysis, the dynamic cues (particularly the seven-point model) had relatively higher classification rates, and vowel duration was found to play a significant role as an additional cue. Our results are in line with dynamic approaches and highlight the importance of looking beyond static cues and beyond the first two formants for further insights into the description and classification of vowel systems

    COMPARATIVE BIOAVAILABILITY (BIOEQUIVALENCE) STUDY FOR FIXED DOSE COMBINATION TABLET CONTAINING AMLODIPINE, VALSARTAN, AND HYDROCHLOROTHIAZIDE USING A NEWLY DEVELOPED HPLC-MS/MS METHOD

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    Objective: The aim of the study was to evaluate the bioequivalence between a newly developed generic tablet containing fixed-dose combination of amlodipine besylate, valsartan and hydrochlorothiazide (10/160/25 mg), and the reference brand product Exforge HCT® tablet; using a newly developed HPLC-MS/MS method for simultaneous determination of these drugs in human plasma.Methods: The brand (reference) and the test (generic) products were administered to thirty-nine healthy subjects. A fasting, laboratory blind, single-dose, two-treatment, two-period, two-sequence, randomized crossover design was conducted with 14 d washout period between dosing. Serial blood samples were withdrawn from each subject immediately before dosing (zero time), and then at 0.33, 0.66, 1.0, 1.33, 1.66, 2.0, 2.5, 3.0, 3.5, 4.0, 5.0, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10, 11, 12, 14, 16, 24, 48 and eventually at 72 h post dosing. Plasma samples were analyzed for simultaneous determination of amlodipine, valsartan and hydrochlorothiazide by a newly developed HPLC coupled with MS/MS detector. The linearity of the method was established for plasma concentration ranges of 0.2-12 ng/ml, 50-8000 ng/ml, and 2-250 ng/ml for amlodipine, valsartan, and hydrochlorothiazide, respectively.Results: Plasma concentration-time data of each individual were analyzed by non-compartmental method to measure the pharmacokinetics parameters; Cmax, Tmax, AUC0-t, AUC0-¥, lZ, T1/2. For amlodipine truncated AUC72hr was calculated. The 90% confidence interval for the pharmacokinetic parameters used for bioequivalence evaluation (Cmax and AUC) for amlodipine, valsartan, and hydrochlorothiazide were well within FDA acceptable ranges of 80-125%.Conclusion: It is concluded that the newly devolved generic product is bioequivalent with the brand product Exforge HCT® tablet. Thus, both products are clinically interchangeable.Keywords: Amlodipine, Valsartan, Hydrochlorothiazide, Pharmacokinetics, Bioequivalence, HPLC-MS/M

    Chronic Toxicity Assessment of Histological Changes and Micronuclei in Fish Cyprinus carpio L. After Exposed to Copper

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    This study was conducted to assess the histological changes of (gill, liver, kidney and muscle) and The micronucleus test were applied in circulating erythrocytes of in freshwater fish common carp, Cyprinus carpio after chronic exposure to copper. For chronic tests, the fish were exposed to different concentrations (0.5, 0.9 and 1.2 mg/L) of copper for 3 and 6 weeks. Control fish were maintained in parallel with the experimental groups. Several histological alterations were observed in the gills, including the epithelium of gill filaments and secondary lamellae, degeneration and congestion of secondary lamellae and short villi. The liver showed dilation in cells hepatic, degenerative and necrosis of hepatocyte cell with mild inflammatory cell and accumulation of cholesterol inside the cell. Regarding in kidney, Renal tissue showed congestion and haemorrhage with certain degeneration and necrosis of renal tubules tissue. In the muscle, showed mild hyalinization of the skeletal muscles fibres with the loss of interstitial fibres in between the muscles fibres and focal degeneration and necrosis with mild inflammatory cell infiltration. Micronucleus test was applied to evaluate the genotoxic effects of heavy metals on Cyprinus carpio. Results of micronucleus test showed a progressive increase in the percentage of micronuclei (P≥0.001) with increases in the intensity of exposure of  copper. The obtained results showed that fish common carp, Cyprinus carpio erythrocytes are good models for cytotoxicity studies

    Therapeutic Drug Monitoring of Cyclosporine Using Single Sampling Strategy

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    Cyclosporine is mainly used as Immunosuppressant after different kinds of transplantation including bone marrow, lungs, kidneys, liver, heart, and other types of organ transplantations. Immunosuppressants diminish organ rejection and elongate the survival of the transplanted organs. Due to the narrow therapeutic ranges and significantly high interindividual and intraindividual variability in blood levels of cyclosporine, there is essential and vital need of therapeutic drug monitoring (TDM) of this drug in order to maintain the patient within the required therapeutic concentrations, which consequently lead to optimizing the clinical outcome and decrease the hazard of toxicity or rejection following organ transplantations. The current review article was aimed to present data for using a single or possibly two blood sampling strategy to be used for TDM of cyclosporine in order to assess the optimal blood levels of cyclosporine used in organ transplant recipients. The results showed that steady state blood concentration of cyclosporine obtained after 2 hours (C2) and possibly after 3 hours (C3) of drug administration are the best sampling time points which reflect total drug exposure (area under blood concentration versus time curve=AUC) and consequently reflecting the effect and the adverse effect(s) of cyclosporine. On the other hand, blood samples obtained at other time points particularly steady state trough concentration obtained before the next dose (C0) demonstrated poor correlation with total drug exposure and consequently the clinical outcome of the drug. Moreover, this study also demonstrated that for organs transplantations TDM of cyclosporine and assessing the clinical conditions of the patients should be routinely performed in order to adjust the dose to get optimal effect and to diminish the adverse effects of the drug. This review article focused on the findings which indicated that monitoring steady-state blood levels of cyclosporine after 2 hours (C2) and likely after 3 hours (C3) of drug intake may be used as ideal surrogate index in TDM of cyclosporine and for predicting the clinical outcome of the drug in all and different types of organs transplantations

    The Effect of Vitamin C and Antacid Tablets (SDI) on the Pharmacokinetics of Aspirin Tablets (SDI) in Human

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    The study explored the effect of vitamin c and antacid on the pharmacokinetics of aspirin in human subjects.  The study was conducted in 12 healthy adults volunteers who were asked to take in the first study, two tablets of aspirin (300 mg) alone. In a second study, the same subjects were given  two tablets of aspirin (300 mg) together with one tablet of vitamin c 500 mg. Eventually, in the third study,  the subjects were administered  two tablets of aspirin (300 mg) and one capsule containing NaHCO3 (500 mg). The three studies were separated by one week wash out period.  In each study, urine was collected from each individual participated in the study at specific time intervals for up to24 hours post dosing to calculate the cumulative amount of salicylate excreted in urine. The excretion rate was plotted against the mid-time sampling time to calculate the elimination rate constant (K), and the elimination half-life (T0.5).  It was found from the current investigation that administration of vitamin c tablet with aspirin tablets reduce (K) values and elongate T0.5, whereas, NaHCO3 intake elevate K values and reduce T0.5 in all subjects participated in the study.             It can be concluded from the current investigation that administration of weak acid drugs like vitamin c, or weak base drugs like antacid have considerable effect on the residence of aspirin in the body and consequently its intensity and duration of clinical effect

    Application of Gaussia luciferase in bicistronic and non-conventional secretion reporter constructs

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    Background: Secreted luciferases are highly useful bioluminescent reporters for cell-based assays and drug discovery. A variety of secreted luciferases from marine organisms have been described that harbor an N-terminal signal peptide for release along the classical secretory pathway. Here, we have characterized the secretion of Gaussia luciferase in more detail. / Results: We describe three basic mechanisms by which GLUC can be released from cells: first, classical secretion by virtue of the N-terminal signal peptide; second, internal signal peptide-mediated secretion and third, non-conventional secretion in the absence of an N-terminal signal peptide. Non-conventional release of dNGLUC is not stress-induced, does not require autophagy and can be enhanced by growth factor stimulation. Furthermore, we have identified the golgi-associated, gamma adaptin ear containing, ARF binding protein 1 (GGA1) as a suppressor of release of dNGLUC. / Conclusions: Due to its secretion via multiple secretion pathways GLUC can find multiple applications as a research tool to study classical and non-conventional secretion. As GLUC can also be released from a reporter construct by internal signal peptide-mediated secretion it can be incorporated in a novel bicistronic secretion system

    Brain herniation in a patient with apparently normal intracranial pressure: a case report

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    Introduction Intracranial pressure monitoring is commonly implemented in patients with neurologic injury and at high risk of developing intracranial hypertension, to detect changes in intracranial pressure in a timely manner. This enables early and potentially life-saving treatment of intracranial hypertension. Case presentation An intraparenchymal pressure probe was placed in the hemisphere contralateral to a large basal ganglia hemorrhage in a 75-year-old Caucasian man who was mechanically ventilated and sedated because of depressed consciousness. Intracranial pressures were continuously recorded and never exceeded 17 mmHg. After sedation had been stopped, our patient showed clinical signs of transtentorial brain herniation, despite apparently normal intracranial pressures (less than 10 mmHg). Computed tomography revealed that the size of the intracerebral hematoma had increased together with significant unilateral brain edema and transtentorial herniation. The contralateral hemisphere where the intraparenchymal pressure probe was placed appeared normal. Our patient underwent emergency decompressive craniotomy and was tracheotomized early, but did not completely recover. Conclusions Intraparenchymal pressure probes placed in the hemisphere contralateral to an intracerebral hematoma may dramatically underestimate intracranial pressure despite apparently normal values, even in the case of transtentorial brain herniation

    P04.74 Preclinical evaluation of combinations targeting the DNA damage response in 2D and 3D models of glioblastoma stem cells

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    Background Despite surgical resection followed by DNA-damaging adjuvant therapies, glioblastoma remain incurable. Increasing evidence demonstrates that aberrations within the DNA damage response (DDR) of cancer stem cells contribute to treatment resistance. We have previously shown that the Fanconi Anaemia (FA) pathway, a key DDR process, remains inactive in normal brain but is re-activated in glioblastoma, making it an appealing foundational target for cancer-specific combination therapies. Since intratumoural heterogeneity in glioblastoma and inherent capacity for functional redundancy within DDR networks are established concepts - we aimed to determine whether combined and hypothesis-driven targeting of the FA pathway along with interconnected DDR processes could form a basis for effective multimodal therapies. Material and Methods Bioinformatic analysis of mRNA expression data (REMBRANDT database) was used to confirm the relevance of FA pathway activity in glioma. Subsequently, immunofluorescence and cell viability assays were used to validate and establish the therapeutic potential of novel FA pathway inhibitors (nFAPi) and inhibition of related DDR targets in established cell models. Finally, combinations targeting the DDR were optimised using immunoblotting, and assessed using clonogenic survival in 2D and novel 3D patient-derived glioblastoma stem cell models. Results High expression of downstream FA pathway genes is strongly associated with poor survival (-17.1% 5-year OS, n=329, Log-rank, P Conclusion Simultaneously targeting the FA pathway and interconnected DDR processes in glioblastoma represents a promising therapeutic strategy. Early mechanistic studies suggest this approach augments DNA damage and enhances IR-induced cell cycle arrest in G2/M, however further preclinical evaluation is ongoing

    Combined inhibition of the Fanconi anaemia (FA) pathway and ATR promotes R-loop generation and profound radiosensitisation in glioblastoma

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    Glioblastoma is a deadly cancer in which treatment resistance is mediated through extensive intratumoural heterogeneity including difficult-to-treat glioblastoma stem cell (GSC) subpopulations. GSC eradication represents an attractive therapeutic goal, but these cells possess upregulated DNA damage response (DDR) processes, resulting in a chemo- and radioresistant phenotype. However, recent studies have demonstrated that elevated replication stress in GSCs may partially explain DDR upregulation and resistance, thus highlighting a potential therapeutically exploitable vulnerability. ATR and the FA-pathway are both fundamental to cellular DNA replication stress responses and maintaining replication fork stability. Since we have previously shown the FA-pathway is inactive in normal brain, but is re-activated in glioblastoma with potential to provide a cancer-specific foundation for combination DDR therapies, we explored the therapeutic potential of simultaneous inhibition of the FA-pathway (FAPi) and ATR (ATRi), in addition to other FA-pathway-based DDR inhibitor (DDRi) combinations. We find that compared with single agent treatments, combined inhibition of the FA-pathway and ATR in both 2D and 3D GSC ex vivo models promotes a substantial increase in conflicts between DNA replication and transcription (R-loops) which is further exacerbated by ionising radiation (IR). Molecular analyses of DNA damage indicate that FAPi+ATRi increases peak DNA damage post-IR treatments, with sustained elevation of DNA damage even at 24 hours post-treatment. In conclusion, simultaneously targeting the FA-pathway and ATR represents an appealing therapeutic strategy for glioblastoma. This approach promotes substantial R-loop generation, likely through exacerbating constitutively high levels of DNA replication stress previously observed in GSCs, with deleterious effects in these treatment resistant cells. Our findings underline the value of developing clinical FA pathway inhibitors and also support the application of current ATR inhibitors to molecularly-selected subsets of glioblastoma, namely, those with defects in one of 22 currently known FA-pathway genes which include BRCA1/FANCS and BRCA2/FANCD1
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