Search

The modest aim of this short article is to provide some new results for a screw dislocation in a functionally graded material within the theory of gradient elasticity. These results, based on a displacement formulation and the Fourier transform technique, complete earlier findings obtained with the stress function method and extends them to the case of the second strain gradient elasticity. Rigorous and easy-to-use analytical expressions for the displacements, strains, and stresses are obtained, which are free from singularities at the dislocation line.

The extremely rich palaeontological record of the horse family, also known as equids, has provided many examples of macroevolutionary change over the last ~55 Mya. This family is also one of the most documented at the palaeogenomic level, with hundreds of ancient genomes sequenced. While these data have advanced understanding of the domestication history of horses and donkeys, the palaeogenomic record of other equids remains limited. In this study, we have generated genome-wide data for 25 ancient equid specimens spanning over 44 Ky and spread across Anatolia, the Caucasus, Central Asia and Mongolia. Our dataset includes the genomes from two extinct species, the European wild ass, Equus hydruntinus, and the sussemione Equus ovodovi. We document, for the first time, the presence of sussemiones in Mongolia and their survival around ~3.9 Kya, a finding that should be considered when discussing the timing of the first arrival of the domestic horse in the region. We also identify strong spatial differentiation within the historical ecological range of Asian wild asses, Equus hemionus, and incomplete reproductive isolation in several groups yet considered as different species. Finally, we find common selection signatures at ANTXR2 gene in European, Asian and African wild asses. This locus, which encodes a receptor for bacterial toxins, shows no selection signal in E. ovodovi, but a 5.4-kb deletion within intron 7. Whether such genetic modifications played any role in the sussemione extinction remains unknown., (© 2024 The Author(s). Molecular Ecology published by John Wiley & Sons Ltd.)

Given the persistent global challenge presented by rapidly spreading diseases, as evidenced notably by the widespread impact of the COVID-19 pandemic on both human health and economies worldwide, the necessity of developing effective infectious disease prediction models has become of utmost importance. In this context, the utilization of online social media platforms as valuable tools in healthcare settings has gained prominence, offering direct avenues for disseminating critical health information to the public in a timely and accessible manner. Propelled by the ubiquitous accessibility of the internet through computers and mobile devices, these platforms promise to revolutionize traditional detection methods, providing more immediate and reliable epidemiological insights. Leveraging this paradigm shift, our proposed framework harnesses Twitter data associated with infectious disease symptoms, employing ontology to identify and curate relevant tweets. Central to our methodology is a hybrid model that integrates XGBoost and Bidirectional Long Short-Term Memory (BiLSTM) architectures. The integration of XGBoost addresses the challenge of handling small dataset sizes, inherent during outbreaks due to limited time series data. XGBoost serves as a cornerstone for minimizing the loss function and identifying optimal features from our multivariate time series data. Subsequently, the combined dataset, comprising original features and predicted values by XGBoost, is channeled into the BiLSTM for further processing. Through extensive experimentation with a dataset spanning multiple infectious disease outbreaks, our hybrid model demonstrates superior predictive performance compared to state-of-the-art and baseline models. By enhancing forecasting accuracy and outbreak tracking capabilities, our model offers promising prospects for assisting health authorities in mitigating fatalities and proactively preparing for potential outbreaks.

The pronounced growth in livestock populations since the 1950s has altered the epidemiological and evolutionary trajectory of their associated pathogens. For example, Marek's disease virus (MDV), which causes lymphoid tumors in chickens, has experienced a marked increase in virulence over the past century. Today, MDV infections kill >90% of unvaccinated birds, and controlling it costs more than US$1 billion annually. By sequencing MDV genomes derived from archeological chickens, we demonstrate that it has been circulating for at least 1000 years. We functionally tested the Meq oncogene, one of 49 viral genes positively selected in modern strains, demonstrating that ancient MDV was likely incapable of driving tumor formation. Our results demonstrate the power of ancient DNA approaches to trace the molecular basis of virulence in economically relevant pathogens.

Since the first report on the pharmacological activity of curcumin in 1949, enormous amounts of research have reported diverse activities for this natural polyphenol found in the dietary spice turmeric. However, curcumin has not yet been used for human application as an approved drug. The clinical translation of curcumin has been hampered due to its low solubility and bioavailability. The improvement in bioavailability and solubility of curcumin can be achieved by its formulation using drug delivery systems. Hydrogels with their biocompatibility and low toxicity effects have shown a substantial impact on the successful formulation of hydrophobic drugs for human clinical trials. This review focuses on hydrogel-based delivery systems for curcumin and describes its applications as anti-cancer as well as wound healing agents., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

What Is Known and Objective: Although antibiotics are ineffective against viral infections, epidemiological studies have revealed that the COVID-19 pandemic resulted in the overuse of antibiotics and disruption of antimicrobial stewardship programmes. We investigated the pattern of antibiotic use during the first 6 months of the COVID-19 pandemic in Iran., Methods: A multi-centre retrospective study was designed to investigate the use of 16 broad-spectrum antibiotics in 12 medical centres. The rate of antibiotic use was calculated and reported based on the Defined Daily Dose (DDD) per 100 hospital bed-days. The bacterial co-infection rate was also reported., Results and Discussion: Totally, 43,791 hospitalized COVID-19 patients were recruited in this study. It was found that 121.6 DDD of antibiotics were used per 100 hospital bed-days, which estimated that each patient received approximately 1.21 DDDs of antibiotics every day. However, the bacterial co-infections were detected only in 14.4% of the cases. A direct correlation was observed between the rate of antibiotic use and mortality (r[142] = 0.237, p = 0.004). The rate of antibiotic consumption was not significantly different between the ICU and non-ICU settings (p = 0.15)., What Is New and Conclusion: In this study, widespread antibiotic use was detected in the absence of the confirmed bacterial coinfection in COVID-19 patients. This over-consumption of broad-spectrum antibiotics may be associated with increased mortality in hospitalized COVID-19 patients, which can be an alarming finding., (© 2022 John Wiley & Sons Ltd.)

Donkeys transformed human history as essential beasts of burden for long-distance movement, especially across semi-arid and upland environments. They remain insufficiently studied despite globally expanding and providing key support to low- to middle-income communities. To elucidate their domestication history, we constructed a comprehensive genome panel of 207 modern and 31 ancient donkeys, as well as 15 wild equids. We found a strong phylogeographic structure in modern donkeys that supports a single domestication in Africa ~5000 BCE, followed by further expansions in this continent and Eurasia and ultimately returning to Africa. We uncover a previously unknown genetic lineage in the Levant ~200 BCE, which contributed increasing ancestry toward Asia. Donkey management involved inbreeding and the production of giant bloodlines at a time when mules were essential to the Roman economy and military.

Background: The aim of this study was to evaluate the rate of apical microleakage following the fracture of five types of nickel-titanium rotary file systems (ProTaper Universal, Mtwo, RaCe, Revo-s, HeroShaper) in the apical one-third of the canal., Materials and Methods: In this laboratory experiment, 49 mandibular premolars were collected and randomly divided into seven groups. Root canal treatment was performed by five different rotary file systems with different cross-sections. All files, except in the control groups, were scratched at the 3-mm end by a handpiece. After separation of the apical end of the file in the root canal, the apical seal was measured, using the fluid infiltration technique. Data were analyzed in SPSS, using one-way ANOVA and Tamhane's T2 tests at P < 0.05., Results: The Hero Shaper and RaCe files showed the highest (3.14 μL/min) and the lowest (2.51 µL/min) rates of microleakage over time, respectively. There were significant differences between the Hero Shaper and RaCe files and between Hero Shaper and ProTaper files in terms of microleakage (Tamhane's T2 tests, P < 0.05)., Conclusion: The presence of a separated file and its cross-section type affects the apical microleakage., Competing Interests: The authors of this manuscript declare that they have no conflicts of interest, real or perceived, financial or nonfinancial in this article., (Copyright: © 2022 Dental Research Journal.)

Domestication of horses fundamentally transformed long-range mobility and warfare 1 . However, modern domesticated breeds do not descend from the earliest domestic horse lineage associated with archaeological evidence of bridling, milking and corralling 2-4 at Botai, Central Asia around 3500 BC 3 . Other longstanding candidate regions for horse domestication, such as Iberia 5 and Anatolia 6 , have also recently been challenged. Thus, the genetic, geographic and temporal origins of modern domestic horses have remained unknown. Here we pinpoint the Western Eurasian steppes, especially the lower Volga-Don region, as the homeland of modern domestic horses. Furthermore, we map the population changes accompanying domestication from 273 ancient horse genomes. This reveals that modern domestic horses ultimately replaced almost all other local populations as they expanded rapidly across Eurasia from about 2000 BC, synchronously with equestrian material culture, including Sintashta spoke-wheeled chariots. We find that equestrianism involved strong selection for critical locomotor and behavioural adaptations at the GSDMC and ZFPM1 genes. Our results reject the commonly held association 7 between horseback riding and the massive expansion of Yamnaya steppe pastoralists into Europe around 3000 BC 8,9 driving the spread of Indo-European languages 10 . This contrasts with the scenario in Asia where Indo-Iranian languages, chariots and horses spread together, following the early second millennium BC Sintashta culture 11,12 ., (© 2021. The Author(s).)

Mummified remains have long attracted interest as a potential source of ancient DNA. However, mummification is a rare process that requires an anhydrous environment to rapidly dehydrate and preserve tissue before complete decomposition occurs. We present the whole-genome sequences (3.94 X) of an approximately 1600-year-old naturally mummified sheep recovered from Chehrābād, a salt mine in northwestern Iran. Comparative analyses of published ancient sequences revealed the remarkable DNA integrity of this mummy. Hallmarks of postmortem damage, fragmentation and hydrolytic deamination are substantially reduced, likely owing to the high salinity of this taphonomic environment. Metagenomic analyses reflect the profound influence of high-salt content on decomposition; its microbial profile is predominated by halophilic archaea and bacteria, possibly contributing to the remarkable preservation of the sample. Applying population genomic analyses, we find clustering of this sheep with Southwest Asian modern breeds, suggesting ancestry continuity. Genotyping of a locus influencing the woolly phenotype showed the presence of an ancestral 'hairy' allele, consistent with hair fibre imaging. This, along with derived alleles associated with the fat-tail phenotype, provides genetic evidence that Sasanian-period Iranians maintained specialized sheep flocks for different uses, with the 'hairy', 'fat-tailed'-genotyped sheep likely kept by the rural community of Chehrābād's miners.

The Aceramic Neolithic (∼9600 to 7000 cal BC) period in the Zagros Mountains, western Iran, provides some of the earliest archaeological evidence of goat ( Capra hircus ) management and husbandry by circa 8200 cal BC, with detectable morphological change appearing ∼1,000 y later. To examine the genomic imprint of initial management and its implications for the goat domestication process, we analyzed 14 novel nuclear genomes (mean coverage 1.13X) and 32 mitochondrial (mtDNA) genomes (mean coverage 143X) from two such sites, Ganj Dareh and Tepe Abdul Hosein. These genomes show two distinct clusters: those with domestic affinity and a minority group with stronger wild affinity, indicating that managed goats were genetically distinct from wild goats at this early horizon. This genetic duality, the presence of long runs of homozygosity, shared ancestry with later Neolithic populations, a sex bias in archaeozoological remains, and demographic profiles from across all layers of Ganj Dareh support management of genetically domestic goat by circa 8200 cal BC, and represent the oldest to-this-date reported livestock genomes. In these sites a combination of high autosomal and mtDNA diversity, contrasting limited Y chromosomal lineage diversity, an absence of reported selection signatures for pigmentation, and the wild morphology of bone remains illustrates domestication as an extended process lacking a strong initial bottleneck, beginning with spatial control, demographic manipulation via biased male culling, captive breeding, and subsequently phenotypic and genomic selection., Competing Interests: The authors declare no competing interest., (Copyright © 2021 the Author(s). Published by PNAS.)

Hippocampal place cells contribute to mammalian spatial navigation and memory formation. Numerous models have been proposed to explain the location-specific firing of this cognitive representation, but the pattern of excitatory synaptic input leading to place firing is unknown, leaving no synaptic-scale explanation of place coding. Here we used resonant scanning two-photon microscopy to establish the pattern of synaptic glutamate input received by CA1 place cells in behaving mice. During traversals of the somatic place field, we found increased excitatory dendritic input, mainly arising from inputs with spatial tuning overlapping the somatic field, and functional clustering of this input along the dendrites over ~10 µm. These results implicate increases in total excitatory input and co-activation of anatomically clustered synaptic input in place firing. Since they largely inherit their fields from upstream synaptic partners with similar fields, many CA1 place cells appear to be part of multi-brain-region cell assemblies forming representations of specific locations.

Introduction: The aim of this study was to determine the prevalence of exposure to hepatitis A by means of serologic markers in chronic hepatitis B patients, with the secondary aim of finding the best prevention method for hepatitis A infection in susceptible groups of our setting., Methods: During the period between 2016 and 2017, we recruited 403 hepatitis B patients aged more than 14 years and regularly attending the infectious diseases clinic at a referral university hospital, Tehran, Iran. A blood sample was collected from all the patients and tested for hepatitis A IgG. The data was analyzed by SPSS v.19., Results: Although none of the patients had previously received hepatitis A vaccine, the results for serologic level of hepatitis A IgG, demonstrated positive results in 379 (94%) cases. The mean age of patients with negative and positive IgG was 29.17 and 42.46 years, respectively; the difference was statistically significant (P≤0.001). The majority of seronegative patients were young adults aged < 25 years and 25 to 35 years (P <0.001)., Conclusion: Seroprevalence of hepatitis A in chronic HBV patients in Iran is high. As HBV infected patients younger than 35 years could be seronagative for HAV infection, evaluation of these patients for HAV infection and vaccination of seronegative patients would be a reasonable approach., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Genome-wide analysis of 67 ancient Near Eastern cattle, Bos taurus, remains reveals regional variation that has since been obscured by admixture in modern populations. Comparisons of genomes of early domestic cattle to their aurochs progenitors identify diverse origins with separate introgressions of wild stock. A later region-wide Bronze Age shift indicates rapid and widespread introgression of zebu, Bos indicus, from the Indus Valley. This process was likely stimulated at the onset of the current geological age, ~4.2 thousand years ago, by a widespread multicentury drought. In contrast to genome-wide admixture, mitochondrial DNA stasis supports that this introgression was male-driven, suggesting that selection of arid-adapted zebu bulls enhanced herd survival. This human-mediated migration of zebu-derived genetics has continued through millennia, altering tropical herding on each continent., (Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Horse domestication revolutionized warfare and accelerated travel, trade, and the geographic expansion of languages. Here, we present the largest DNA time series for a non-human organism to date, including genome-scale data from 149 ancient animals and 129 ancient genomes (≥1-fold coverage), 87 of which are new. This extensive dataset allows us to assess the modern legacy of past equestrian civilizations. We find that two extinct horse lineages existed during early domestication, one at the far western (Iberia) and the other at the far eastern range (Siberia) of Eurasia. None of these contributed significantly to modern diversity. We show that the influence of Persian-related horse lineages increased following the Islamic conquests in Europe and Asia. Multiple alleles associated with elite-racing, including at the MSTN "speed gene," only rose in popularity within the last millennium. Finally, the development of modern breeding impacted genetic diversity more dramatically than the previous millennia of human management., (Copyright © 2019 The Author(s). Published by Elsevier Inc. All rights reserved.)

Neurons in hippocampal output area CA1 are thought to exhibit redundancy across cortical and hippocampal inputs. Here we show instead that acute silencing of CA3 terminals drastically reduces place field responses for many CA1 neurons, while a smaller number are unaffected or have increased responses. These results imply that CA3 is the predominant driver of CA1 place cells under normal conditions, while also revealing heterogeneity in input dominance across cells.

Fragile X syndrome (FXS) is the most common heritable cause of intellectual disability and single-gene cause of autism spectrum disorder. The Fmr1 null mouse models much of the human disease including hyperarousal, sensory hypersensitivity, seizure activity, and hippocampus-dependent cognitive impairment. Sleep architecture is disorganized in FXS patients, but has not been examined in Fmr1 knockout (Fmr1-KO) mice. Hippocampal neural activity during sleep, which is implicated in memory processing, also remains uninvestigated in Fmr1-KO mice. We performed in vivo electrophysiological studies of freely behaving Fmr1-KO mice to assess neural activity, in the form of single-unit spiking and local field potential (LFP), within the hippocampal CA1 region during multiple differentiated sleep and wake states. Here, we demonstrate that Fmr1-KO mice exhibited a deficit in rapid eye movement sleep (REM) due to a reduction in the frequency of bouts of REM, consistent with sleep architecture abnormalities of FXS patients. Fmr1-KO CA1 pyramidal cells (CA1-PCs) were hyperactive in all sleep and wake states. Increased low gamma power in CA1 suggests that this hyperactivity was related to increased input to CA1 from CA3. By contrast, slower sharp-wave ripple events (SWRs) in Fmr1-KO mice exhibited longer event duration, slower oscillation frequency, with reduced CA1-PC firing rates during SWRs, yet the incidence rate of SWRs remained intact. These results suggest abnormal neuronal activity in the Fmr1-KO mouse during SWRs, and hyperactivity during other wake and sleep states, with likely adverse consequences for memory processes., (Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.)

Current genetic data are equivocal as to whether goat domestication occurred multiple times or was a singular process. We generated genomic data from 83 ancient goats (51 with genome-wide coverage) from Paleolithic to Medieval contexts throughout the Near East. Our findings demonstrate that multiple divergent ancient wild goat sources were domesticated in a dispersed process that resulted in genetically and geographically distinct Neolithic goat populations, echoing contemporaneous human divergence across the region. These early goat populations contributed differently to modern goats in Asia, Africa, and Europe. We also detect early selection for pigmentation, stature, reproduction, milking, and response to dietary change, providing 8000-year-old evidence for human agency in molding genome variation within a partner species., (Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

The Eneolithic Botai culture of the Central Asian steppes provides the earliest archaeological evidence for horse husbandry, ~5500 years ago, but the exact nature of early horse domestication remains controversial. We generated 42 ancient-horse genomes, including 20 from Botai. Compared to 46 published ancient- and modern-horse genomes, our data indicate that Przewalski's horses are the feral descendants of horses herded at Botai and not truly wild horses. All domestic horses dated from ~4000 years ago to present only show ~2.7% of Botai-related ancestry. This indicates that a massive genomic turnover underpins the expansion of the horse stock that gave rise to modern domesticates, which coincides with large-scale human population expansions during the Early Bronze Age., (Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Background: Mining frequent gene regulation sequential patterns in time course microarray datasets is an important mining task in bioinformatics. Although finding such patterns are of paramount important for studying a disease, most existing work do not consider gene-disease association during gene regulation sequential pattern discovery. Moreover, they consider more absent/existence effects of genes during the mining process than taking the degrees of genes expression into account. Consequently, such techniques discover too many patterns which may not represent important information to biologists to investigate the relationships between the disease and underlying reasons hidden in gene regulation sequences., Results: We propose a utility model by considering both the gene-disease association score and their degrees of expression levels under a biological investigation. We propose an efficient method called Top-HUGS, for discoverying significant high utility gene regulation sequential patterns from a time-course microarray dataset., Conclusions: In this study, the proposed methods were evaluated on a publicly available time course microarray dataset. The experimental results show higher accuracies compared to the baseline methods. Our proposed methods found that several new gene regulation sequential patterns involved in such patterns were useful for biologists and provided further insights into the mechanisms underpinning biological processes. To effectively work with the proposed method, a web interface is developed to our system using Java. To the best of our knowledge, this is the first demonstration for significant high utility gene regulation sequential pattern discovery.

As a consequence of conditioning visual cues with delayed reward, cue-evoked neural activity that predicts the time of expected future reward emerges in the primary visual cortex (V1). We hypothesized that this reward-timing activity is engendered by a reinforcement signal conveying reward acquisition to V1. In lieu of behavioral conditioning, we assessed in vivo whether selective activation of either basal forebrain (BF) or cholinergic innervation is sufficient to condition cued interval-timing activity. Substituting for actual reward, optogenetic activation of BF or cholinergic input within V1 at fixed delays following visual stimulation entrains neural responses that mimic behaviorally conditioned reward-timing activity. Optogenetically conditioned neural responses express cue-evoked temporal intervals that correspond to the conditioning intervals, are bidirectionally modifiable, display experience-dependent refinement, and exhibit a scale invariance to the encoded delay. Our results demonstrate that the activation of BF or cholinergic input within V1 is sufficient to encode cued interval-timing activity and indicate that V1 itself is a substrate for associative learning that may inform the timing of visually cued behaviors., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Using immunohistology, electron microscopy, electrophysiology and optogenetics, we found that proliferating adult mouse hippocampal neural precursors received immature GABAergic synaptic inputs from parvalbumin-expressing interneurons. Recently shown to suppress adult quiescent neural stem cell activation, parvalbumin interneuron activation promoted newborn neuronal progeny survival and development. Our results suggest a niche mechanism involving parvalbumin interneurons that couples local circuit activity to the diametric regulation of two critical early phases of adult hippocampal neurogenesis.

The cognitive symptoms of schizophrenia presumably result from impairments of information processing in neural circuits. We recorded neural activity in the hippocampus of freely behaving mice that had a forebrain-specific knockout of the synaptic plasticity-mediating phosphatase calcineurin and were previously shown to exhibit behavioral and cognitive abnormalities, recapitulating the symptoms of schizophrenia. Calcineurin knockout (KO) mice exhibited a 2.5-fold increase in the abundance of sharp-wave ripple (SWR) events during awake resting periods and single units in KO were overactive during SWR events. Pairwise measures of unit activity, however, revealed that the sequential reactivation of place cells during SWR events was completely abolished in KO. Since this relationship during postexperience awake rest periods has been implicated in learning, working memory, and subsequent memory consolidation, our findings provide a mechanism underlying impaired information processing that may contribute to the cognitive impairments in schizophrenia., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background and Purpose: Ureteral stents often cause significant patient morbidity that can be difficult to treat. Drug-eluting stent technology allows the local delivery of a drug. Our previous work demonstrated that ketorolac instilled intravesically at the time of ureteral stent insertion significantly decreased flank pain compared with controls. We sought to determine the safety of a novel ketorolac-eluting ureteral stent., Materials and Methods: A total of 92 Yorkshire pigs were randomized to 1 of 5 groups. The oral control group consisted of 12 animals with transurethrally inserted control ureteral stents and 5 days of oral ketorolac. Twenty animals in each of the remaining groups received a control stent, or 15%, 13%, or 7% ketorolac-loaded stents. Ketorolac levels were measured in plasma, urine, and tissue sampled from ureters, bladder, kidneys, and liver using high performance liquid chromatography. Necropsies were performed to evaluate tissue pathology., Results: The majority of ketorolac was released within the first 30 days. The highest levels of ketorolac in plasma, kidney, and liver occurred in the oral control group. The highest levels of ketorolac found in ureteral and bladder tissues occurred in the ketorolac-stent groups in a dose-dependent fashion. No adverse events were noted in any of the ketorolac-stent groups. Gastric ulcerations were identified only in the oral control group. No abnormalities were identified in any other internal organs in any group., Conclusions: The use of ketorolac-eluting ureteral stents has proven to be safe in a porcine model. The ketorolac-stent group had less than 12% of the ketorolac concentration in plasma, kidney, and liver tissues compared with the oral ketorolac group. Ureteral tissues displayed the highest levels of ketorolac. Clinical studies are needed to determine if ketorolac-elution reduces stent symptoms.

In this paper, a heuristic method for determining the optimal number of clusters is proposed. Four clustering algorithms, namely K-means, Growing Neural Gas, Simulated Annealing based technique, and Fuzzy C-means in conjunction with three well known cluster validity indices, namely Davies-Bouldin index, Calinski-Harabasz index, Maulik-Bandyopadhyay index, in addition to the proposed index are used. Our simulations evaluate capability of mentioned indices in some artificial and medical datasets.

A method for the analysis and characterization of therapeutic and diagnostic oligonucleotides has been developed using a combination of liquid chromatography and mass spectrometry (LC-MS). The optimized ion-pairing buffers permit a highly efficient separation of native and chemically modified antisense oligonucleotides (AS-ODNs) from their metabolites or failure synthetic products. The mobile phases were MS compatible, allowing for direct and sensitive analysis of components eluting from the column. The method was applied for the quantitation and characterization of AS-ODNs, including phosphorothioates and 2'-O-methyl-modified phosphorothioates. Tandem LC-MS analysis confirmed the identity of the oligonucleotide metabolites, failure products, the presence of protection groups not removed after synthesis, and the extent of depurination or phosphorothioate backbone oxidation.

Accurate urinary measurements of the two major metabolites of phenytoin, 5-(p-hydroxyphenyl)-5-phenylhydantoin (p-HPPH) and 5-(3,4-dihydroxy-cyclohexa-1,5-dienyl)-5-phenylhydantoin (dihydrodiol, DHD), are necessary for pharmacokinetic and drug-interaction studies of this commonly used antiepileptic drug. We describe a simple, rapid, acid hydrolysis, with liquid-liquid extraction and simultaneous isocratic reversed-phase high-performance liquid chromatography of p-HPPH and 5-(m-hydroxyphenyl)-5-phenylhydantoin (m-HPPH) (hydrolytic end product of DHD). p-HPPH and m-HPPH were quantitated against their separate respective internal standards of alphenal and tolylbarb. The mobile phase consisted of water-dioxane-tetrahydrofuran (80:15:5, v/v/v) at 2 ml/min and at 50 degrees C, with detection at 225 nm. Baseline separation was achieved by use of a 16 cm x 3.9 mm Nova-Pak C18 column and total analysis time of 12 min. p-HPPH and m-HPPH concentrations ranged from 10 to 200 and from 2 to 30 micrograms/ml, respectively, with between-day coefficients of variations of 3.3-4.5% and 2.2-5.1% for controls. All standard curves were linear with r values greater than 0.993. The DHD concentration was determined by multiplying m-HPPH concentrations by 2.3.

The relationships between magnitude of response to orally administered carbidopa/levodopa (CD/LD) and serum/cerebrospinal fluid (CSF) concentrations of levodopa (LD), 3-O-methyldopa (3-O-MD), and homovanillic acid (HVA) were studied in 15 patients with chronic LD-treated Parkinson disease. The degree of clinical benefit derived from a 25/250 tablet of CD/LD could not be correlated with absolute serum levels of LD, 3-O-MD or LD/3-O-MD ratios. CSF levels of LD and 3-O-MD were also not associated with improvement. CSF levels of HVA, however, did significantly correlate with magnitude of response to LD. Furthermore, CSF HVA levels were not dependent on previous LD dosage. Our data suggest that in chronic LD-treated patients, central factors related to the integrity of the nigrostriatal tract may be a more important determinant of magnitude of response to LD than peripheral elements affecting the amount of LD entering the central nervous system.

The bioavailability of phenytoin from ACC-9653 versus intravenously administered sodium phenytoin was determined using a crossover design for intravenous and intramuscular administration of ACC-9653 to healthy volunteers. Absolute bioavailability of phenytoin derived from ACC-9653 in each subject was calculated as the ratio of the phenytoin area under the plasma concentration time curve for time 0 to infinity [AUC(0-inf)] after ACC-9653 divided by the phenytoin AUC(0-inf) after intravenous sodium phenytoin. The mean absolute bioavailability of ACC-9653 was 0.992 after intravenous administration and 1.012 after intramuscular administration. These data establish that the bioavailability of ACC-9653 is complete following intravenous or intramuscular administration in single-dose volunteer studies. The absolute bioavailability of phenytoin derived from ACC-9653 in subjects with therapeutic plasma phenytoin concentrations is being studied in patients given simultaneous infusions of stable isotope-labeled tracer doses of ACC-0653 and sodium phenytoin.