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Journal of Natural Products Jul 2021Monosaccharides play important roles in living organisms. They are present in essential glycoproteins, nucleic acids, and glycolipids as well as cell walls and bioactive...
Monosaccharides play important roles in living organisms. They are present in essential glycoproteins, nucleic acids, and glycolipids as well as cell walls and bioactive natural product glycosides and polysaccharides. Monosaccharides are optically active, and as a routine, scientists make sure that their absolute configurations are determined when new natural glycosides are isolated. Many determination methods for the absolute configuration of monosaccharides have been reported, and thus far, taking advantage of their optical rotation differences is the most used and efficient method to distinguish enantiomers. This method, however, is not very convenient, because it requires a milligram amount of each pure sample and the availability of a polarimeter. Identification methods dealing with comparison of the retention times of the d- and l-diastereomeric monosaccharide derivatives by GC, TLC values, HPLC, or UPLC have been also reported. Although effective, these methods still require sample preparation and a few milligrams of the test compounds. A new method with simple sample preparation to distinguish enantiomers of monosaccharides by analyzing the H NMR spectra of their diastereomeric derivatives has been developed. The monosaccharide components of a commercially available saponin-rich and monoglycosides have been successfully identified using this procedure.
Topics: Biological Products; Magnetic Resonance Spectroscopy; Molecular Structure; Monosaccharides; Panax; Stereoisomerism
PubMed: 34191514
DOI: 10.1021/acs.jnatprod.0c01120 -
Pediatrics Nov 2007Stimulant medications (amphetamine and methylphenidate) are the best-documented treatments for attention-deficit/hyperactivity disorder, but their short pharmacokinetic... (Review)
Review
Stimulant medications (amphetamine and methylphenidate) are the best-documented treatments for attention-deficit/hyperactivity disorder, but their short pharmacokinetic and behavioral half-lives have historically produced irksome time-course effects. New drug-delivery systems designed to eliminate the need for frequent dosing include the methylphenidate transdermal system, in which the matrix acts as both the drug reservoir and the skin adhesive. The methylphenidate transdermal system patch, in contrast to long-acting oral preparations, requires a paradigmatic shift in clinical thinking, as well as refinement of clinical management skills. For dosing with the methylphenidate transdermal system patch, clinicians must think in terms of a retrievable form of drug delivery (in milligrams per hour) rather than a fixed nonretrievable dose (in milligrams per dose or milligrams per day). Clinicians and patients can determine the optimal clinical dose by controlling 2 variables: (1) patch size (controlling milligrams per hour) and (2) duration of patch wear. The new paradigm is worth learning, because the patch offers several advantages over oral preparations for some patients, chiefly individualized control over effect duration (determined by when the patch is applied in the morning and removed in the afternoon/evening). Taking full advantage of this treatment option requires educating the patient and parents regarding practical elements of daily use. These elements include patch-site selection, application techniques, management of wear time to optimize the daily time course of clinical benefits, and skin hygiene. This article summarizes clinical principles that physicians may find useful in managing this new addition to the attention-deficit/hyperactivity disorder treatment armamentarium.
Topics: Attention Deficit Disorder with Hyperactivity; Central Nervous System Stimulants; Delayed-Action Preparations; Drug Delivery Systems; Humans; Patient Education as Topic; Physician's Role
PubMed: 17974748
DOI: 10.1542/peds.2007-0542 -
Biodegradation Apr 20221,4-Dioxane is a pervasive and persistent contaminant in numerous aquifers. Although the median concentration in most contaminant plumes is in the microgram per liter...
1,4-Dioxane is a pervasive and persistent contaminant in numerous aquifers. Although the median concentration in most contaminant plumes is in the microgram per liter range, a subset of sites have contamination in the milligram per liter range. Most prior studies that have examined 1,4-dioxane concentrations in the hundreds of milligrams per liter range have been performed with industrial wastewater. The main objective of this study was to evaluate aerobic biodegradation of 1,4-dioxane in microcosms prepared with soil and groundwater from a site where concentrations range from ~ 1500 mg·L in the source zone, to 450 mg·L at a midpoint of the groundwater plume, and to 6 mg·L at a down-gradient location. Treatments included biostimulation with propane, addition of propane and a propanotrophic enrichment culture (ENV487), and unamended. The highest rates of biodegradation for each location in the plume occurred in the bioaugmented treatments, although indigenous propanotrophs also biodegraded 1,4-dioxane to below 25 µg·L. Nutrient additions were required to sustain biodegradation of propane and cometabolism of 1,4-dioxane. Among the unamended treatments, biodegradation of 1,4-dioxane was detected in the mid-gradient microcosms. An isolate was obtained that grows on 1,4-dioxane as a sole source of carbon and energy and identified through whole-genome sequencing as Pseudonocardia dioxivorans BERK-1. In a prior study, the same strain was isolated from an aquifer in the southeastern United States. Monod kinetic parameters for BERK-1 are similar to those for strain CB1190.
Topics: Biodegradation, Environmental; Dioxanes; Propane; Water Pollutants, Chemical
PubMed: 35102492
DOI: 10.1007/s10532-022-09971-4 -
Advances in Colloid and Interface... Jul 2016This review summarizes the current state of knowledge regarding interfacial properties of very complex biological colloids, specifically, human meibum and tear lipids,... (Review)
Review
This review summarizes the current state of knowledge regarding interfacial properties of very complex biological colloids, specifically, human meibum and tear lipids, and their interactions with proteins similar to the proteins found in aqueous part of human tears. Tear lipids spread as thin films over the surface of tear-film aqueous and play crucial roles in tear-film stability and overall ocular-surface health. The vast majority of papers published to date report interfacial properties of meibum-lipid monolayers spread on various aqueous sub-phases, often containing model proteins, in Langmuir trough. However, it is well established that natural human ocular tear lipids exist as multilayered films with a thickness between 30 and 100nm, that is very much disparate from 1 to 2nm thick meibum monolayers. We employed sessile-bubble tensiometry to study the dynamic interfacial and rheological properties of reconstituted multilayered human tear-lipid films. Small amounts (0.5-1μg) of human tear lipids were deposited on an air-bubble surface to produce tear-lipid films in thickness range 30-100nm corresponding to ocular lipid films. Thus, we were able to overcome major Langmuir-trough method limitations because ocular tear lipids can be safely harvested only in minute, sub-milligram quantities, insufficient for Langmuir through studies. Sessile-bubble method is demonstrated to be a versatile tool for assessing conventional synthetic surfactants adsorption/desorption dynamics at an air-aqueous solution interface. (Svitova T., Weatherbee M., Radke C.J. Dynamics of surfactant sorption at the air/water interface: continuous-flow tensiometry. J. Colloid Interf. Sci. 2003;261:1170-179). The augmented flow-sessile-bubble setup, with step-strain relaxation module for dynamic interfacial rheological properties and high-precision syringe pump to generate larger and slow interfacial area expansions-contractions, was developed and employed in our studies. We established that this method is uniquely suitable for examination of multilayered lipid-film interfacial properties. Recently it was compellingly proven that chemical composition of human tear lipids extracted from whole tears is substantially different from that of meibum lipids. To be exact, healthy human tear lipids contain 8-16% of polar lipids, similar to lung lipids, and they are mostly double-tailed phospholipids, with C16 and longer alkyl chains. Rationally, one would assume that the results obtained for meibum lipids, devoid of surface-active components such as phospholipids, and, above all, in a form of monolayers, are not pertinent or useful for elucidating behavior and stability of an averaged 60-nm thick ocular tear-lipid films in vivo. The advantage of sessile-bubble technique, specifically, using a small amount of lipids required to attain multilayered films, unlocks the prospect of evaluating and comparing the interfacial properties of human tear lipids collected from a single individual, typically 100-150μg. This is in sharp contrast with several milligrams of lipids that would be required to build equally thick films for Langmuir-trough experiments. The results of our studies provided in-depth understanding of the mechanisms responsible for properties and stability of human tear-lipid films in vivo. Here we summarize recent publications and our latest findings regarding human tear-lipid interfacial properties, their chemical composition, and their interaction with model proteins mimicking the proteins found in human tear-aqueous phase.
Topics: Eye Proteins; Humans; Lacrimal Apparatus; Lipids; Meibomian Glands; Rheology; Surface Tension; Tears; Viscosity
PubMed: 26830077
DOI: 10.1016/j.cis.2015.12.009 -
Annals of Emergency Medicine Jun 2018We determine episodic and high-quantity prescribers' contribution to opioid prescriptions and total morphine milligram equivalents in California, especially among...
STUDY OBJECTIVE
We determine episodic and high-quantity prescribers' contribution to opioid prescriptions and total morphine milligram equivalents in California, especially among individuals prescribed large amounts of opioids.
METHODS
This was a cross-sectional descriptive analysis of opioid prescribing patterns during an 8-year period using the de-identified Controlled Substance Utilization Review and Evaluation System (CURES) database, the California subsection of the prescription drug monitoring program. We took a 10% random sample of all patients and stratified them by the amount of prescription opioids obtained during their maximal 90-day period. We identified "episodic prescribers" as those whose prescribing pattern included short-acting opioids on greater than 95% of all prescriptions, fewer than or equal to 31 pills on 95% of all prescriptions, only 1 prescription in the database for greater than 90% of all patients to whom they gave opioids, fewer than 6 prescriptions in the database to greater than 99% of patients given opioids, and fewer than 540 prescriptions per year. We identified top 5% prescribers by their morphine milligram equivalents per day in the database. We examined the relationship between patient opioid prescriptions and provider type, with the primary analysis performed on the patient cohort who received only short-acting opioids in an attempt to avoid guideline-concordant palliative, oncologic, and addiction care, and a secondary analysis performed on all patients.
RESULTS
Among patients with short-acting opioid only, episodic prescribers (14.6% of 173,000 prescribers) wrote at least one prescription to 25% of 2.7 million individuals but were responsible for less than 9% of the 10.5 million opioid prescriptions and less than 3% of the 3.9 billion morphine milligram equivalents in our sample. Among individuals with high morphine milligram equivalents use, episodic prescribers were responsible for 2.8% of prescriptions and 0.6% of total morphine milligram equivalents. Conversely, the top 5% of prescribers prescribed at least 29.8% of prescriptions and 48.8% of total morphine milligram equivalents, with a greater contribution in patients with high morphine milligram equivalents.
CONCLUSION
Episodic prescribers contribute minimally to total opioid prescriptions, especially among individuals categorized as using high morphine milligram equivalents. Interventions focused on reducing opioid prescriptions in the episodic care setting are unlikely to yield important reductions in the prescription opioid supply; conversely, targeting high-quantity prescribers has the potential to create substantial reductions.
Topics: Analgesics, Opioid; California; Cross-Sectional Studies; Databases, Factual; Drug Utilization Review; Emergency Service, Hospital; Episode of Care; Humans; Morphine; Practice Patterns, Physicians'; Prescription Drug Misuse
PubMed: 29275945
DOI: 10.1016/j.annemergmed.2017.10.016 -
Plant Molecular Biology Mar 1985We have developed a DNA extraction procedure for milligram amounts of plant tissue. Yields ranged from 0.3-200 nanograms of DNA per milligram of tissue. The factors...
We have developed a DNA extraction procedure for milligram amounts of plant tissue. Yields ranged from 0.3-200 nanograms of DNA per milligram of tissue. The factors affecting yield are discussed. Fresh tissue, as well as herbarium specimens (22-118 years old) and mummified seeds and embryos (500 to greater than 44 600 years old) were used. All tissues attempted (57 types from 29 species) yielded measurable amounts of DNA. In no case tested was inhibition observed for restriction enzymes BamHI or EcoRI.
PubMed: 24306565
DOI: 10.1007/BF00020088 -
The American Journal of Drug and... Nov 2023There is currently no format-independent method to determine delta-9-tetrahydrocannabinol (THC) in milligrams for self-report studies. Validate self-report method for...
There is currently no format-independent method to determine delta-9-tetrahydrocannabinol (THC) in milligrams for self-report studies. Validate self-report method for quantifying mg THC from commercially available cannabis products using product labeling, which includes both net weight and product potency. 53 adult cannabis users (24 M, 29F), 21-39 years of age ( = 28.38, SD = 4.15), were instructed to report daily use via a weekly survey for two consecutive weeks, provide product label photographs, abstain from use for 24 h, submit a urine sample and complete the Cannabis Use Disorder Identification Test - Revised (CUDIT-R) and the Marijuana Craving Questionnaire - Short Form (MCQ-SF). Milligrams of THC were determined by multiplying quantity of product used by its THC concentration. Urine was analyzed for the urine metabolite 11-nor-carboxy-THC (THC-COOH) via liquid chromatography mass spectroscopy. THC and THC-COOH values were log10 transformed prior to correlational analyses. Median daily THC consumption was 102.53 mg ( = 203.68, SD = 268.13). Thirty-three (62%) of the 53 participants reported using two or more formats over the 2-week period. There was a significant positive correlation between log10 THC-COOH and log10 THC mg (r(41) = .59, < .001), log10 THC mg and MCQ-SF score (r(41) = .59, < .001), and log10 THC mg dose and CUDIT-R score, (r(41) = .39, = .010). Our label-based methodology provides consumption information across all modalities of cannabis use in standard units that can be combined across products for calculation of dose. It is a viable and valid method for quantifying mg of THC consumed and can be utilized in any region where cannabis is legal, and labeling is regulated.
Topics: Adult; Humans; Cannabis; Dronabinol; Self Report; Gas Chromatography-Mass Spectrometry; Hallucinogens; Cannabinoid Receptor Agonists; Substance Abuse Detection
PubMed: 37506343
DOI: 10.1080/00952990.2023.2232525 -
Talanta Jul 1967A simple and rapid method has been developed for the determination of milligram amounts of aromatic amines and phenols. An aliquot containing 2-4 mg of sample is...
A simple and rapid method has been developed for the determination of milligram amounts of aromatic amines and phenols. An aliquot containing 2-4 mg of sample is dissolved in a mixture of hydrochloric and acetic acids and allowed to react with N-bromo-succinimide, the excess of which is determined iodometrically after the reaction is over. The reaction time varies from 1-10 min and the absolute error generally is negative, ranging from -1 to -4%.
PubMed: 18960171
DOI: 10.1016/0039-9140(67)80108-5 -
Methods in Molecular Biology (Clifton,... 2014For pharmaceutical applications of plasmid DNA, either direct or indirect, certain quality standards are required. Whereas for direct gene transfer into human "Good...
For pharmaceutical applications of plasmid DNA, either direct or indirect, certain quality standards are required. Whereas for direct gene transfer into human "Good Manufacturing Practice" (GMP) grade is mandatory, for GMP production of, e.g., viral vectors (AAV, etc.) the plasmid DNA used needs not necessarily be produced under GMP. Besides such regulatory aspects up-scaling of the plasmid DNA production process from research laboratory scale (up to a few milligrams) to industrial scales (milligram to gram scales) is an issue that is addressed here.
Topics: Batch Cell Culture Techniques; Genetic Vectors; Plasmids; Vaccines, DNA
PubMed: 24715291
DOI: 10.1007/978-1-4939-0410-5_14 -
The Analyst Aug 2016Currently, the separation targets of preparative electrophoresis range from milligrams to micrograms of proteins. However, most commercially available preparative...
Currently, the separation targets of preparative electrophoresis range from milligrams to micrograms of proteins. However, most commercially available preparative electrophoretic instruments function at the milligram level. Although some preparative electrophoretic apparatuses operated at the microgram level, the fractionation results are often unsatisfying because they suffer from low resolution, poor recovery, or a long fractionation time. To address these issues, we developed a novel microscale preparative electrophoresis system that consists of a separation apparatus and an elution apparatus. Protein samples are first loaded onto the separation apparatus and separated over the gel according to the molecular weight of each protein. Then the separation gel is transferred to the elution apparatus and the proteins on the gel are eluted through the thickness of the gel. This system offers the following advantages: (1) high resolution: almost no overlap between the adjacent fractions; (2) a short recovery time: fractionation was performed in 2 hours including separation in 100 min and elution in 20 min and (3) high recovery: recovery was as high as 91.8%.
Topics: Electrophoresis, Polyacrylamide Gel; Molecular Weight; Proteins
PubMed: 27306831
DOI: 10.1039/c6an00780e