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Forensic Toxicology Jan 2024We developed and validated a method for quantitative analysis of ten synthetic cathinones in oral fluid (OF) samples, using microextraction by packed sorbent (MEPS) for...
Green analytical toxicology method for determination of synthetic cathinones in oral fluid samples by microextraction by packed sorbent and liquid chromatography-tandem mass spectrometry.
PURPOSE
We developed and validated a method for quantitative analysis of ten synthetic cathinones in oral fluid (OF) samples, using microextraction by packed sorbent (MEPS) for sample preparation followed by liquid chromatography‒tandem mass spectrometry (LC‒MS/MS).
METHOD
OF samples were collected with a Quantisal™ device and 200 µL was extracted using a C18 MEPS cartridge installed on a semi-automated pipette and then analyzed using LC‒M/SMS.
RESULTS
Linearity was achieved between 0.1 and 25 ng/mL, with a limit of detection (LOD) of 0.05 ng/mL and a limit of quantification (LOQ) of 0.1 ng/mL. Imprecision (% relative standard deviation) and bias (%) were better than 11.6% and 7.5%, respectively. The method had good specificity and selectivity against 9 different blank OF samples (from different donors) and 68 pharmaceutical and drugs of abuse with concentrations varying between 400 and 10,000 ng/mL. No evidence of carryover was observed. The analytes were stable after three freeze/thaw cycles and when kept in the autosampler (10 °C) for up to 24 h. The method was successfully applied to quantify 41 authentic positive samples. Methylone (mean 0.6 ng/mL, median 0.2 ng/mL), N-ethylpentylone (mean 16.7 ng/mL, median 0.35 ng/mL), eutylone (mean 39.1 ng/mL, median 3.6 ng/mL), mephedrone (mean 0.5 ng/mL, median 0.5 ng/mL), and 4-chloroethcathinone (8.1 ng/mL) were quantified in these samples.
CONCLUSION
MEPS was an efficient technique for Green Analytical Toxicology purposes, which required only 650 µL organic solvent and 200 µL sodium hydroxide, and the BIN cartridge had a lifespan of 100 sample extractions.
Topics: Chromatography, Liquid; Synthetic Cathinone; Tandem Mass Spectrometry; Solid Phase Microextraction; Limit of Detection
PubMed: 37505359
DOI: 10.1007/s11419-023-00671-z -
Frontiers in Veterinary Science 2024Mosquito-borne diseases pose serious public health threats in Zhejiang Province, China, and vector control is believed to be the primary method for reducing...
BACKGROUND
Mosquito-borne diseases pose serious public health threats in Zhejiang Province, China, and vector control is believed to be the primary method for reducing transmission. Due to severe resistance problems, effective and sustainable methods without chemical insecticides are urgently required to control mosquito vectors. Attractive toxic sugar baits (ATSB) are newly developed methods to control mosquitoes in recent decades with the core element sugar bait, which was invented according to the sugar-feeding behavior of mosquitoes. In this study, we developed a Novel Sugar Bait Device (NSBD) trap by combining sugar bait and physical adhesive capture technology. The study aimed to evaluate the effect of the NSBD trap on controlling mosquitoes in residential environments and to identify the optimal sugar solution concentration in the sugar bait of the NSBD for real use.
METHODS
Four residential villages in Ningbo City with similar geographic environments and mosquito densities were selected for field trials in 2022. One village (site 1) was designated as the control group, and three villages (sites 2-4) served as the test groups to assess the effectiveness of NSBD traps with different sugar solution concentrations (6, 8, and 10%) in the sugar bait. Larval and adult mosquito densities were monitored monthly before and semi-monthly after the trials using the CDC light trap and larval pipette method.
RESULTS
Before the trials, we monitored mosquito density for 3 months to confirm the baseline mosquito density among the four sites, and no statistical differences in adult and larval mosquitoes were found (adult, = 3.047, > 0.05; larvae, = 0.436, > 0.05). After the trials, all NCBD traps effectively controlled larval and adult mosquito densities, with the highest standard decrease rates of larval and adult mosquito densities at 57.80 and 86.31%, respectively, observed in site 4. The most suitable sugar solution concentration in the sugar bait was 10%.
CONCLUSION
NSBD traps effectively controlled mosquitoes in residential environments during field trials. Without the use of insecticides, this may be a promising choice for mosquito vector control to prevent mosquito-borne diseases.
PubMed: 38601912
DOI: 10.3389/fvets.2024.1364740 -
JBRA Assisted Reproduction Sep 2023Endogenous prostaglandins are involved in hemostasis, renal excretion of electrolytes, and implicated in dysmenorrhea. Piroxicam and Nitroglycerin are common drugs used...
OBJECTIVE
Endogenous prostaglandins are involved in hemostasis, renal excretion of electrolytes, and implicated in dysmenorrhea. Piroxicam and Nitroglycerin are common drugs used in treating dysmenorrhea by inhibiting the cyclooxygenase pathway involved in prostaglandin production. However, studies comparing the effects of these drugs on prostaglandin-modulated hemostasis and renal function are lacking.
METHODS
Fifteen female rats (120-160g) were divided into 3 groups (20 per group), namely Control (distilled water, 0.3 mL), Piroxicam treated (3mg/kg) and Nitroglycerin treated (1 mg/kg). Di-estrous phase was confirmed in animals in each group using the Pipette smear method. Treatment was administered for 4 days covering the estrous cycle. Bleeding and clotting time were assessed and blood concentrations of sodium, potassium, urea and platelet counts were evaluated in all phases. Data were analyzed using one-way ANOVA and Newman-Keuls post-hoc test. Statistical significance was considered at p<0.0.
RESULTS
The nitroglycerin-treated group showed significant increases in blood potassium during di-estrous while the piroxicam-treated group showed significant increases in blood potassium, urea and clotting time with a significant decrease in sodium levels during di-estrous compared to controls. Results obtained in other phases were not significant compared to controls.
CONCLUSIONS
The study showed that Nitroglycerin produces minimum alteration of blood and electrolyte indices compared to piroxicam during di-estrous.
Topics: Humans; Female; Rats; Animals; Piroxicam; Rats, Wistar; Nitroglycerin; Cyclooxygenase Inhibitors; Prostaglandins; Dysmenorrhea; Urea; Sodium; Electrolytes; Potassium
PubMed: 37134015
DOI: 10.5935/1518-0557.20220069 -
BioRxiv : the Preprint Server For... Mar 2024The small amount of human tissue available for testing is a paramount challenge in cancer drug development, cancer disease models, and personalized oncology....
The small amount of human tissue available for testing is a paramount challenge in cancer drug development, cancer disease models, and personalized oncology. Technologies that combine the microscale manipulation of tissues with fluid handling offer the exciting possibility of miniaturizing and automating drug evaluation workflows. This approach minimizes animal testing and enables inexpensive, more efficient testing of samples with high clinical biomimicry using scarce materials. We have developed an inexpensive platform based on an off-the-shelf robot that can manipulate microdissected tissues (µDTs) into user-programmed positions without using intricate microfluidic designs nor any other accessories such as a microscope or a pneumatic controller. The robot integrates complex functions such as vision and fluid actuation by incorporating simple items including a USB camera and a rotary pump. Through the robot's camera, the platform software optically recognizes randomly-seeded µDTs on the surface of a petri dish and positions a mechanical arm above the µDTs. Then, a custom rotary pump actuated by one of the robot's motors generates enough microfluidic lift to hydrodynamically pick and place µDTs with a pipette at a safe distance from the substrate without requiring a proximity sensor. The platform's simple, integrated construction is cost-effective and compact, allowing placement inside a tissue culture hood for sterile workflows. The platform enables users to select µDTs based on their size, place them in user-programmed arrays, such as multi-well plates, and control various robot motion parameters. As a case application, we use the robotic system to conduct semi-automated drug testing of mouse and human µDTs in 384-well plates. Our user-friendly platform promises to democratize microscale tissue research to clinical and biological laboratories worldwide.
PubMed: 38586030
DOI: 10.1101/2024.03.21.586169 -
Crystal Growth & Design Nov 2023Controllable continuous release of functional materials from capsules is one of the unmet functions of theragnosis particles; on this way, understanding cargo-fluid...
Controllable continuous release of functional materials from capsules is one of the unmet functions of theragnosis particles; on this way, understanding cargo-fluid interactions in vitro is an essential milestone. We develop a flexible platform to investigate single particle-fluid interactions utilizing a glass micropipette as a highly localized flow source around an optically trapped particle. In proof-of-concept experiments, this microparticle is sensitive to local microflow distribution, thus serving as a probe. The very same flows are capable of the particle rotating (i.e., vaterite drug cargo) at frequencies dependent on the mutual particle-pipette position. Platform flexibility comes from different interactions of a tweezer (optical forces) and a pipette (mechanical/hydrodynamical) with a microparticle, which makes this arrangement an ideal microtool. We studied the vaterite dissolution kinetics and demonstrated that it can be controlled on demand, providing a wide cargo release dynamic rate. Our results promote the use of inorganic mesoporous nanoparticles as a nanomedicine platform.
PubMed: 37937190
DOI: 10.1021/acs.cgd.3c00799 -
Biomedical Journal Aug 2023Intercellular coupling is essential for the suprachiasmatic nucleus (SCN) to serve as a coherent central clock. Synaptic release of neurotransmitters and neuropeptides...
BACKGROUND
Intercellular coupling is essential for the suprachiasmatic nucleus (SCN) to serve as a coherent central clock. Synaptic release of neurotransmitters and neuropeptides is critical for synchronizing SCN neurons. However, intercellular coupling via non-synaptic mechanisms has also been demonstrated. In particular, the abundant perikaryal appositions with morphological specializations in the narrow extracellular space (ECS) may hinder molecular diffusion to allow for ion accumulation or depletion.
METHODS
The SCN neurons were recorded in the whole-cell current-clamp mode, with pipette filled with high (26 mM)-Na or low (6 mM)-Na solution.
RESULTS
Cells recorded with high-Na pipette solution could fire spontaneous action potentials (AP) with peak AHP more negative than the calculated value of K equilibrium potential (E) and with peak AP more positive than calculated E. Cells recorded with low-Na pipette solution could also have peak AHP more negative than calculated E. In contrast, the resting membrane potential (RMP) was always less negative to calculated E. The distribution and the averaged amplitude of peak AHP, peak AP, or RMP was similar between cells recorded with high-Na and low-Na solution pipette. In a number of cells, the peak AHP could increase from more positive to become more negative than calculated E spontaneously or after treatments to hyperpolarize the RMP. TTX blocked the Na -dependent APs and tetraethylammonium (TEA), but not Ba or Cd, markedly reduced the peak AHP. Perforated-patch cells could also but rarely fire APs with peak AHP more negative than calculated E.
CONCLUSION
The result of peak AHP negative to calculated E indicates that local [K] sensed by the TEA-sensitive AHP K channels must be lower than bulk [K], most likely due to K clearance from K diffusion-restricted ECS by the Na/K-ATPase. The K diffusion-restricted ECS may allow for K-mediated ionic interactions among neurons to regulate SCN excitability.
Topics: Humans; Extracellular Space; Membrane Potentials; Action Potentials; Suprachiasmatic Nucleus; Neurons; Tetraethylammonium
PubMed: 35863667
DOI: 10.1016/j.bj.2022.07.005 -
PloS One 2023Plate-based proteomic sample preparation offers a solution to the large sample throughput demands in the biotechnology field where hundreds or thousands of engineered...
Plate-based proteomic sample preparation offers a solution to the large sample throughput demands in the biotechnology field where hundreds or thousands of engineered microbes are constructed for testing is routine. Meanwhile, sample preparation methods that work efficiently on broader microbial groups are desirable for new applications of proteomics in other fields, such as microbial communities. Here, we detail a step-by-step protocol that consists of cell lysis in an alkaline chemical buffer (NaOH/SDS) followed by protein precipitation with high-ionic strength acetone in 96-well format. The protocol works for a broad range of microbes (e.g., Gram-negative bacteria, Gram-positive bacteria, non-filamentous fungi) and the resulting proteins are ready for tryptic digestion for bottom-up quantitative proteomic analysis without the need for desalting column cleanup. The yield of protein using this protocol increases linearly with respect to the amount of starting biomass from 0.5-2.0 OD*mL of cells. By using a bench-top automated liquid dispenser, a cost-effective and environmentally-friendly option to eliminating pipette tips and reducing reagent waste, the protocol takes approximately 30 minutes to extract protein from 96 samples. Tests on mock mixtures showed expected results that the biomass composition structure is in close agreement with the experimental design. Lastly, we applied the protocol for the composition analysis of a synthetic community of environmental isolates grown on two different media. This protocol has been developed to facilitate rapid, low-variance sample preparation of hundreds of samples and allow flexibility for future protocol development.
Topics: Acetone; Proteomics; Proteins; Indicators and Reagents
PubMed: 37418444
DOI: 10.1371/journal.pone.0288102 -
BMC Women's Health Apr 2024Women presenting with abnormal uterine bleeding needs careful and thorough assessment including ultrasound examination of endometrium and histopathological assessment of...
Rate and risk factors of inadequate endometrial tissues after endometrial sampling among Bhutanese women at the national referral hospital of Bhutan: a cross-sectional study.
INTRODUCTION
Women presenting with abnormal uterine bleeding needs careful and thorough assessment including ultrasound examination of endometrium and histopathological assessment of the endometrial tissues. The objective of this cross-sectional study was to determine the rate and the factors associated with inadequate endometrial tissues after endometrial sampling using MedGyn® pipette among Bhutanese women at the colposcopy clinic, Jigme Dorji Wangchuck National Referral Hospital (JDWNRH), Bhutan.
METHODS
This cross-sectional study was conducted at the colposcopy clinic, JDWNRH, Thimphu between October, 2021 and March, 2022. Women included in this study underwent endometrial sampling using MedGyn® pipette without anesthesia as an office procedure. Data were collected using an interviewer-administered questionnaire and results extracted into a structured pro forma. The histopathology reports were extracted from the Department of Pathology and Laboratory Medicine, JDWNRH using the unique Bhutanese citizenship identity card number of the study participants.
RESULTS
Inadequate endometrial tissues were noted in 27% (33 out of 122 cases). Among 89 patients with an adequate endometrial tissue, histologic results were normal in 30 (33.7%), benign pathology in 22 (24.7%), atrophy in 10 (8.2%), and hyperplasia in 27 (30.3%). In a univariate analysis, menopausal state (OR 1.6, 95% CI 0.708-3.765), overweight and obese (OR 1.6 95% CI 0.640-3.945), unemployed (OR 1.7, 95% CI 0.674-1.140), nulliparous (OR 1.7, 95% CI 0.183-15.816), primipara (OR 5.1, 95% CI 0.635-40.905) and use of hormonal contraception (OR 2.1, 95% CI 0.449-10.049) were associated with increased risk of inadequate endometrial tissues. On multivariate regression analysis, nulliparity (OR 1.1, 95% CI 0.101-12.061), overweight and obesity (OR 1.4, 95% CI 0.490-3.917), use of hormonal contraceptives (OR 2.2, 95% CI 0.347-13.889), and junior surgeons (OR 1.1, 95%CI 0.463-2.443) were found to be associated with inadequate endometrial tissues. However, the above associations were not statistically significant (p > 0.05).
CONCLUSION
The rate of inadequate endometrial tissue following endometrial sampling using MedGyn® pipette was 27.0%. Factors associated with an increased risk of inadequate endometrial tissue after endometrial sampling were menopausal state, overweight and obese, unemployed, nulliparous, primipara and use of hormonal contraception.
Topics: Humans; Female; Bhutan; Cross-Sectional Studies; Overweight; Endometrium; Obesity; Risk Factors; Referral and Consultation; Uterine Hemorrhage; Endometrial Neoplasms
PubMed: 38566186
DOI: 10.1186/s12905-024-03047-6 -
The Journal of Biological Chemistry Apr 2024Mechanically activated Piezo1 channels undergo transitions from closed to open-state in response to pressure and other mechanical stimuli. However, the molecular details...
Mechanically activated Piezo1 channels undergo transitions from closed to open-state in response to pressure and other mechanical stimuli. However, the molecular details of these mechanosensitive gating transitions are unknown. Here, we used cell-attached pressure-clamp recordings to acquire single channel data at steady-state conditions (where inactivation has settled down), at various pressures and voltages. Importantly, we identify and analyze subconductance states of the channel which were not reported before. Pressure-dependent activation of Piezo1 increases the occupancy of open and subconductance state at the expense of decreased occupancy of shut-states. No significant change in the mean open time of subconductance states was observed with increasing negative pipette pressure or with varying voltages (ranging from -40 to -100 mV). Using Markov-chain modeling, we identified a minimal four-states kinetic scheme, which recapitulates essential characteristics of the single channel data, including that of the subconductance level. This study advances our understanding of Piezo1-gating mechanism in response to discrete stimuli (such as pressure and voltage) and paves the path to develop cellular and tissue level models to predict Piezo1 function in various cell types.
Topics: Humans; HEK293 Cells; Ion Channel Gating; Ion Channels; Kinetics; Markov Chains; Mechanotransduction, Cellular; Pressure
PubMed: 38479601
DOI: 10.1016/j.jbc.2024.107156 -
Human Reproduction (Oxford, England) May 2024Is there a cumulative toxicity of disposables used in IVF procedures? (Observational Study)
Observational Study
STUDY QUESTION
Is there a cumulative toxicity of disposables used in IVF procedures?
SUMMARY ANSWER
A toxicity may be detected when consumables are used cumulatively, while no toxicity is detected when the same consumables are used and tested individually.
WHAT IS KNOWN ALREADY
Many components of items used in IVF laboratories may impair human embryonic development. Consequently, it is necessary to screen all reagents and materials which could be in contact with gametes and embryos. Toxicity tests, such as the mouse embryo assay and the human sperm motility assay (HSMA), are used by manufacturers as quality control tools to demonstrate the safety of their products. This evaluation is currently individually performed for each single consumable. However, during an IVF cycle, several devices are used sequentially, potentially creating a cumulative exposure to chemical contaminants, which could not be detected for individually tested consumables.
STUDY DESIGN, SIZE, DURATION
The objective of this observational study conducted from March 2021 to October 2022 was to evaluate with the HSMA methodology if there was a cumulative toxicity when several disposables are sequentially used. Fourteen categories of consumables currently used in routine IVF procedures were studied, which included devices used for sperm and oocyte collection (cups, condoms, and oocyte aspiration needles), manipulation (flasks, tubes, tips, pipettes, embryo transfer catheters, syringes, and gloves), culture (dishes), and storage (straws).
PARTICIPANTS/MATERIALS, SETTING, METHODS
After obtaining patient consent, the surplus semen assessed as having normal parameters according to the World Health Organization 2010 criteria were used to perform the HSMAs. First, each consumable was tested individually. Then, associations of three, four, and five consumables, previously validated as non-toxic when tested individually, were analyzed. HSMAs were conducted three times to ensure reproducibility, with a defined toxicity threshold of a sperm motility index (SMI) below 0.85 in at least two of three tests.
MAIN RESULTS AND THE ROLE OF CHANCE
Thirty-six references of disposables were first individually tested across 53 lots. Forty-nine (92%) demonstrated compliance. However, four (8%) devices revealed toxicity: one lot of 1 ml syringes, two lots of sperm cups, and one lot of 25 cm2 flasks. These four references were excluded from the IVF routine procedures. A total of 48 combinations of consumables were assessed, involving 41 lots from 32 references that were previously individually tested. Among the evaluated combinations, 17 out of 48 (35%) associations exhibited toxicity with a SMI below 0.85 for two of the three tests (n = 8) or all the three tests (n = 9). Notably, three out of 17 (18%) of the three-consumable associations, five out of 16 (31%) of the four-consumable associations, and nine out of 15 (60%) of the five-consumable associations were found not compliant. The toxicity did not originate from a single consumable, because only consumables that were individually pre-validated as non-toxic were included in the combinations, but the toxicity had a cumulative origin. The risk of cumulative toxicity increased with the number of consumables included in the association (Cochran-Mantel-Haenszel statistic, P = 0.013).
LIMITATIONS, REASONS FOR CAUTION
The high proportion of non-compliant combinations of disposables can be attributed directly to the extreme rigorous extraction conditions employed during the tests, which could deviate from the conditions encountered in routine clinical use. Also, the methodology employed in the HSMAs (e.g. toxicity extraction duration, sperm concentrations, and protein supplementation of the medium) can influence the sensitivity of the tests.
WIDER IMPLICATIONS OF THE FINDINGS
This study highlights the significance of performing toxicity testing on devices before introducing them into clinical practice. Disposables should be tested individually to detect immediate toxicities and also in combination. Our results advocate rationalizing the number of consumables used in each IVF procedure and re-evaluating the use of glass consumables.
STUDY FUNDING/COMPETING INTEREST(S)
This study received fundings from GCS Ramsay Santé pour l'Enseignement et la Recherche (Paris, France) and the Centre de Biologie Médicale BIOGROUP (Le Chesnay-Rocquencourt, France). The authors declare that they have no conflict of interest that could be perceived as prejudicing the impartiality of the reported research.
TRIAL REGISTRATION NUMBER
N/A.
Topics: Humans; Fertilization in Vitro; Male; Female; Sperm Motility; Mice; Animals; Toxicity Tests; Embryonic Development; Spermatozoa
PubMed: 38438162
DOI: 10.1093/humrep/deae028