50 research outputs found

    Optimirana i validirana protočna injekcijska spektrofotometrijska analiza topiramata, piracetama i levetiracetama u farmaceutskim pripravcima

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    Application of a sensitive and rapid flow injection analysis (FIA) method for determination of topiramate, piracetam, and levetiracetam in pharmaceutical formulations has been investigated. The method is based on the reaction with ortho-phtalaldehyde and 2-mercaptoethanol in a basic buffer and measurement of absorbance at 295 nm under flow conditions. Variables affecting the determination such as sample injection volume, pH, ionic strength, reagent concentrations, flow rate of reagent and other FIA parameters were optimized to produce the most sensitive and reproducible results using a quarter-fraction factorial design, for five factors at two levels. Also, the method has been optimized and fully validated in terms of linearity and range, limit of detection and quantitation, precision, selectivity and accuracy. The method was successfully applied to the analysis of pharmaceutical preparations.Opisana je osjetljiva i brza protočna injekcijska analiza (FIA) za određivanje topiramata, piracetama i levetiracetama u farmaceutskim pripravcima. Metoda se temelji na reakciji ortho-ftalaldehida i 2-merkaptoetanola u bazičnom puferu i mjerenju apsorbancije na 295 nm u protočnim uvjetima. U svrhu povećanja osjetljivosti i dobivanja reproducibilnih rezultata optimirane su varijable koje utječu na određivanje kao što su volumen injektiranog uzorka, pH, ionska jakost, koncentracija reagensa, brzina protoka reagensa i drugi FIA parametri koristeći četvrt-frakcijski faktorijalni dizajn, za pet faktora na dva nivoa. Metoda je optimirana i potpuno validirana (linearnost, područje određivanja, granica detekcije i kvantifikacije, preciznost, selektivnost i točnost). Metoda je uspješno primijenjena za analizu farmaceutskih pripravaka

    Endogenous bone marrow stem cell mobilization in rats: Its potential role in homing and repair of damaged inner ear

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    AbstractThe stem cells are widely used in the last few years in different fields of medicine, either by external transplantation or endogenous mobilization, most of these studies are still experimental on animals; few were tried on humans as in the spinal cord injury or myocardial infarction. As regards its use in the inner ear, stem cell transplantation was examined in many previous studies, while the mobilization idea is a new method to be experimented in inner ear hair cell regeneration.The aim of this work was to assess the use of GCSF to induce bone marrow SC mobilization to home and repair the damaged inner ear hair cells in rats after the damage had been inflicted by Amikacin injection.First we had to develop an animal model for damaged inner ear, so we used the well known ototoxic effect of Amikacin intra-tympanic injection till we reached complete loss of hearing function. And this can be assessed by DPOAEs. Now we have an animal model of damaged inner ear hair cells and mobilization of bone marrow SCs was induced by subcutaneous injection of G-CSF for 5days.Clinical assessment was done using DPOAEs before and after G-CSF injection also histological assessment of the inner ear was done before and after G-CSF by two methods H&E staining and Scanning Electron Microscopy.The results of histological examination of the specimens showed some promising changes that may be responsible for the improvement of hearing function in some rats that was detected by OAEs

    Stability study of thymoquinone, carvacrol and thymol using HPLC-UV and LC-ESI-MS

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    The aim of this study was to investigate the stability of three major antioxidants of Nigella sativa: thymoquinone (TQ), carvacrol (CR) and thymol (THY), under different stress conditions using HPLC and LC-MS/MS. Forced degradation for each compound was performed under different conditions, including oxidation, hydrolysis, photolysis and thermal decomposition. The results showed that both CR and THY were stable under the studied conditions, whereas TQ was not affected by acidic, basic and oxidative forced conditions but the effect of light and heat was significant. The degradation products of TQ were further investigated and characterized by LC-MS/MS. HPLC-UV method has been fully validated in terms of linearity and range, the limit of detection and quantitation, precision, selectivity, accuracy and robustness. The method was successfully applied to quantitative analysis of the principal antioxidants of Nigella sativa TQ, CR and THY in different phytopharmaceuticals

    Non-manifesting AHI1 truncations indicate localized loss-of-function tolerance in a severe Mendelian disease gene

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    Determination of variant pathogenicity represents a major challenge in the era of high-throughput sequencing. Erroneous categorization may result if variants affect genes that are in fact dispensable. We demonstrate that this also applies to rare, apparently unambiguous truncating mutations of an established disease gene. By whole-exome sequencing (WES) in a consanguineous family with congenital non-syndromic deafness, we unexpectedly identified a homozygous nonsense variant, p.Arg1066*, in AHI1, a gene associated with Joubert syndrome (JBTS), a severe recessive ciliopathy. None of four homozygotes expressed any signs of JBTS, and one of them had normal hearing, which also ruled out p.Arg1066* as the cause of deafness. Homozygosity mapping and WES in the only other reported JBTS family with a homozygous C-terminal truncation (p.Trp1088Leufs*16) confirmed AHI1 as disease gene, but based on a more N-terminal missense mutation impairing WD40-repeat formation. Morpholinos against N-terminal zebrafish Ahi1, orthologous to where human mutations cluster, produced a ciliopathy, but targeting near human p.Arg1066 and p.Trp1088 did not. Most AHI1 mutations in JBTS patients result in truncated protein lacking WD40-repeats and the SH3 domain; disease was hitherto attributed to loss of these protein interaction modules. Our findings indicate that normal development does not require the C-terminal SH3 domain. This has far-reaching implications, considering that variants like p.Glu984* identified by preconception screening (‘Kingsmore panel') do not necessarily indicate JBTS carriership. Genomes of individuals with consanguineous background are enriched for homozygous variants that may unmask dispensable regions of disease genes and unrecognized false positives in diagnostic large-scale sequencing and preconception carrier screenin

    Effects of water shortage on food legume crops

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    The clamor for agricultural resources is being pushed up by global climatic change and population growth. Such consequences are huge challenges to food security, wreaking havoc on the agroecosystem and causing biotic and abiotic stresses in plants, which in turn cause metabolic and physiological problems. Food legume crops contribute to food security in underdeveloped countries by playing an essential role in conservation farming methods. Drought has, nevertheless, exhibited a negative impact on productivity in many parts of the world. While water shortage is a significant abiotic barrier to legume crop output, drought impacts differ depending on drought timing, agro-climatic area, soil texture, and legume species. To resolve these concerns, we gathered data from the recent publications that revealed drought-induced changes in the production of monoculture legumes in field circumstances and examined it using meta-analysis approaches. Research findings revealed that the water cut’s quantity was strongly associated with a decrease in yield. However, the magnitude of the effect differed depending on the phenological stage of the drought and legume species. The legumes such as groundnut and lentil exhibited the lowest yield reductions (31.2% and 19.6% for groundnut and lentil, accordingly), however, the biggest yield drop (39.8%) facing the maximum water reduction was for faba bean

    DTYMK is essential for genome integrity and neuronal survival

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    Nucleotide metabolism is a complex pathway regulating crucial cellular processes such as nucleic acid synthesis, DNA repair and proliferation. This study shows that impairment of the biosynthesis of one of the building blocks of DNA, dTTP, causes a severe, early-onset neurodegenerative disease. Here, we describe two unrelated children with bi-allelic variants in DTYMK, encoding dTMPK, which catalyzes the penultimate step in dTTP biosynthesis. The affected children show severe microcephaly and growth retardation with minimal neurodevelopment. Brain imaging revealed severe cerebral atrophy and disappearance of the basal ganglia. In cells of affected individuals, dTMPK enzyme activity was minimal, along with impaired DNA replication. In addition, we generated dtymk mutant zebrafish that replicate this phenotype of microcephaly, neuronal cell death and early lethality. An increase of ribonucleotide incorporation in the genome as well as impaired responses to DNA damage were observed in dtymk mutant zebrafish, providing novel pathophysiological insights. It is highly remarkable that this deficiency is viable as an essential component for DNA cannot be generated, since the metabolic pathway for dTTP synthesis is completely blocked. In summary, by combining genetic and biochemical approaches in multiple models we identified loss-of-function of DTYMK as the cause of a severe postnatal neurodegenerative disease and highlight the essential nature of dTTP synthesis in the maintenance of genome stability and neuronal survival

    Characterization of greater middle eastern genetic variation for enhanced disease gene discovery

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    The Greater Middle East (GME) has been a central hub of human migration and population admixture. The tradition of consanguinity, variably practiced in the Persian Gulf region, North Africa, and Central Asia1-3, has resulted in an elevated burden of recessive disease4. Here we generated a whole-exome GME variome from 1,111 unrelated subjects. We detected substantial diversity and admixture in continental and subregional populations, corresponding to several ancient founder populations with little evidence of bottlenecks. Measured consanguinity rates were an order of magnitude above those in other sampled populations, and the GME population exhibited an increased burden of runs of homozygosity (ROHs) but showed no evidence for reduced burden of deleterious variation due to classically theorized ‘genetic purging’. Applying this database to unsolved recessive conditions in the GME population reduced the number of potential disease-causing variants by four- to sevenfold. These results show variegated genetic architecture in GME populations and support future human genetic discoveries in Mendelian and population genetics

    Anthropometric craniofacial pattern profiles in microcephaly

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    Craniofacial measurements were taken in 60 cases prsenting with microcephaly. The cases were classified etiologically and morphologically and the letter was further subclassified. Craniofacial pattern profiles, cranial capasity, and the pattern vriability index were calculated and compared with normal Hungarian controls of the same age and sex. In addition, correlation analysis between cranial capacity and IQ was done. Our results show significant similarity of the craniofacial pattern profiles between isolated microcephaly (IMC) and multiple microcephaly (MMC), and between primary microcephaly (PMC) and secondary microcephaly (SMC). The pattern variability index of the microcephalic caseswas 4.77. There was no correlation between cranial capacity and IQ in the icrocephalic patients

    Anthropometric craniofacial pattern profiles in microcephaly

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    Craniofacial measurements were taken in 60 cases prsenting with microcephaly. The cases were classified etiologically and morphologically and the letter was further subclassified. Craniofacial pattern profiles, cranial capasity, and the pattern vriability index were calculated and compared with normal Hungarian controls of the same age and sex. In addition, correlation analysis between cranial capacity and IQ was done. Our results show significant similarity of the craniofacial pattern profiles between isolated microcephaly (IMC) and multiple microcephaly (MMC), and between primary microcephaly (PMC) and secondary microcephaly (SMC). The pattern variability index of the microcephalic caseswas 4.77. There was no correlation between cranial capacity and IQ in the icrocephalic patients
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