Usability of the SB11 Pre-filled Syringe (PFS) in Patients with Retinal Diseases.

INTRODUCTION: SB11 (Byooviz™; Samsung Bioepis Co., Ltd.) is a ranibizumab (Lucentis®; Genentech, Inc.) biosimilar targeting vascular endothelial growth factor A for the treatment of retinal diseases. The pre-filled syringe (PFS) presentation of SB11 offers an alternative administration method to the vial, with the potential for enhanced safety and efficient syringe preparation. The objective of this study was to assess the ability of healthcare professionals (HCPs) to follow the instructions for use to prepare and administer SB11 PFS intravitreal (IVT) injections to patients with neovascular age-related macular degeneration (nAMD) or macular edema secondary to retinal vein occlusion (RVO). METHODS: This study was an open-label, single-arm, single-dose clinical study to evaluate the usability of the SB11 PFS in patients with nAMD or macular edema secondary to RVO. Four HCPs prepared and administered 0.5 mg SB11 PFS IVT injections to 34 patients. Product use task completion (12 tasks in total) was assessed by independent observers. Safety was assessed up to 7 days after injection of the investigational product. RESULTS: A total of 34 patients were enrolled and completed the study. All 12 tasks were successfully completed in 34 (100%) patients without a use-related failure. Most patients (32 patients, 94.1%) experienced no adverse events (AEs), whereas 2 (5.9%) patients experienced three treatment-emergent AEs (TEAEs) which were mild to moderate in severity. There were no severe or serious TEAEs reported during the study. CONCLUSIONS: This study showed that HCPs were able to successfully prepare and administer the SB11 PFS via IVT injection. No unexpected safety issues were identified. The SB11 PFS is a promising alternative for therapeutic administration of SB11 in patients with retinal disease. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT06176963; EudraCT number 2021-003566-12.

Mechanical release of homogenous proteins from supramolecular gels.

A long-standing challenge is how to formulate proteins and vaccines to retain function during storage and transport and to remove the burdens of cold-chain management. Any solution must be practical to use, with the protein being released or applied using clinically relevant triggers. Advanced biologic therapies are distributed cold, using substantial energy, limiting equitable distribution in low-resource countries and placing responsibility on the user for correct storage and handling. Cold-chain management is the best solution at present for protein transport but requires substantial infrastructure and energy. For example, in research laboratories, a single freezer at -80 °C consumes as much energy per day as a small household1. Of biological (protein or cell) therapies and all vaccines, 75% require cold-chain management; the cost of cold-chain management in clinical trials has increased by about 20% since 2015, reflecting this complexity. Bespoke formulations and excipients are now required, with trehalose2, sucrose or polymers3 widely used, which stabilize proteins by replacing surface water molecules and thereby make denaturation thermodynamically less likely; this has enabled both freeze-dried proteins and frozen proteins. For example, the human papilloma virus vaccine requires aluminium salt adjuvants to function, but these render it unstable against freeze-thaw4, leading to a very complex and expensive supply chain. Other ideas involve ensilication5 and chemical modification of proteins6. In short, protein stabilization is a challenge with no universal solution7,8. Here we designed a stiff hydrogel that stabilizes proteins against thermal denaturation even at 50 °C, and that can, unlike present technologies, deliver pure, excipient-free protein by mechanically releasing it from a syringe. Macromolecules can be loaded at up to 10 wt% without affecting the mechanism of release. This unique stabilization and excipient-free release synergy offers a practical, scalable and versatile solution to enable the low-cost, cold-chain-free and equitable delivery of therapies worldwide.

Effect of a brush tip on in-office bleaching gels in an attachable syringe: Hydrogen peroxide penetration, bleaching efficacy and amount of gel expended.

OBJECTIVE: Evaluate the penetration of hydrogen peroxide (HP) into the pulp chamber, bleaching efficacy (BE) and amount of gel expended during in-office bleaching using an applicator brush tip and conventional tip from different commercial brands. MATERIALS AND METHODS: 104 human premolars were randomly distributed into thirteen groups (n = 8) according to the commercial brand: DSP White Clinic 35 % Calcium (DW), Nano White 35 % (NW), Total Blanc One-Step 35 % (TS), Whiteness HP Blue 35 % (WB), Potenza Bianco Pro SS 38 % (PB), Opalescence XTra Boost 40 % (OB), no bleaching (negative control), and application method: applicator brush tip and conventional tip for all groups. Initial HP concentration (%) was determined via titration and pH was measured with digital pH meter. Concentration (µg/mL) of HP into the pulp chamber was measured using UV-Vis spectrophotometry, the BE (ΔE*ab, ΔE00 and ΔWID) was evaluated with a digital spectrophotometer, and the amount of gel expended was evaluated using a precision analytical digital balance. Statistical analysis included two-way ANOVA, Tukey's, and Dunnett's test. Comparison between HP into the pulp chamber vs BE was performed with Person's correlation (α = 0.05). RESULTS: Brush tip demonstrated a low amount of HP in the pulp chamber compared to the conventional method for all bleaching gels (p < 0.0003), as well as lower amount of gel expended (p < 0.002). The brush tip did not result in a significant difference in BE compared to the conventional (p > 0.05). No correlations were found between both factors (p > 0.05). CONCLUSION: Brush tip showed lower penetration of HP in the pulp chamber and a reduced volume of spent gel when compared to the conventional tip, for all commercial brands. CLINICAL RELEVANCE: Brush tip is recommended for bleaching gels in an attachable syringe due to its ability to reduce the penetration of HP into the pulp chamber and minimize the amount of bleaching gel used.

When Are "Paraphernalia" Critical Medical Supplies?

Evidence of harm reduction interventions' morbidity and mortality benefits is abundant and of high quality, so there are good reasons for regional and national groups to advocate for more widespread distribution of legally regulated "drug paraphernalia," including needles, syringes, and fentanyl test strips. But lack of consistency among states' laws means that patients' interstate travel can subject them to being charged with possession of illegal items. This commentary on a case offers guidance to clinicians looking to help patients understand legal risks of interstate travel with supplies that are prescribed or recommended to reduce harms of their drug use and explores the ethical responsibilities of physicians in jurisdictions that legally prohibit these harm reduction interventions.

Genotypic and morphological identification of opportunistic microorganisms in triple-syringe tubing from dental units.

BACKGROUND: In Mexico and around the world, water in dental units, including triple syringes, comes from municipal chlorinated water mains. The microbial contamination of dental unit water systems constitutes a risk factor for opportunistic infections. OBJECTIVES: The present work aimed to identify the bacteria present in the triple-syringe water lines of dental units at a dental school of a public university in Mexico, with a hypothesis that opportunistic bacteria of importance to human health would be found. MATERIAL AND METHODS: A cross-sectional study was carried-out. A total of 100 samples of triple-syringe tubing from dental units operated by a dental school of a public university in Mexico were analyzed before and after their use in dental practice. Bacterial biofilm was cultured and isolated from the tubing, using standard microbiological methods, and then the species present were identified through 16S rRNA gene sequencing. The characterization of the biofilm was performed by means of scanning electron microscopy (SEM). RESULTS: Bacterial growth was observed in 20% of the non-disinfected and 10% of the disinfected samples, with 11 strains isolated. Six genera and 11 bacterial species were genetically identified. Coagulasenegative staphylococci (CoNS), considered opportunistic human pathogens, were among the most critical microorganisms. Scanning electron microscopy revealed a thick polymeric matrix with multiple bacterial aggregates. CONCLUSIONS: Opportunistic bacteria from human skin and mucous membranes were detected. Under normal conditions, these bacteria are incapable of causing disease, but are potentially harmful to immunosuppressed patients.

Pharmacokinetics and safety of candidate tocilizumab biosimilar CT-P47 administered by auto-injector or pre-filled syringe: a randomized, open­label, single-dose phase I study.

BACKGROUND: This study compared the pharmacokinetics (PK), immunogenicity, and safety of candidate tocilizumab biosimilar, CT-P47, administered via auto-injector (CT-P47 AI) or pre-filled syringe (CT-P47 PFS), in healthy Asian adults. RESEARCH DESIGN AND METHODS: In this phase I, multicenter, open-label study, participants were randomized 1:1 to receive a single 162 mg/0.9 mL dose of CT-P47 via AI or PFS. Primary endpoints were area under the concentration - time curve from time zero to infinity (AUC0-inf) and maximum serum concentration (Cmax). PK equivalence was determined if 90% confidence intervals (CIs) for the ratios of geometric least-squares means (gLSMs) were within the predefined 80-125% equivalence margin. Secondary PK parameters, immunogenicity, and safety outcomes were also assessed. RESULTS: Of 314 participants randomized (155 CT-P47 AI; 159 CT-P47 PFS), 310 received the study drug (153 CT-P47 AI; 157 CT-P47 PFS). Primary and secondary PK results, immunogenicity and safety were similar between groups. Ninety percent CIs for the ratio of gLSMs were within the predefined equivalence margin for AUC0-inf (85.87-102.94) and Cmax (82.98-98.16). CONCLUSIONS: PK equivalence between CT-P47 AI and CT-P47 PFS was demonstrated in healthy Asian adults, with comparable immunogenicity and safety between the two devices. TRIAL REGISTRATION: ClinicalTrials.gov: NCT05617183.

Tocilizumab is a biologic medicine used to treat inflammatory diseases, such as rheumatoid arthritis. A biosimilar is a drug that is an almost identical copy of an approved original ('reference') biologic medicine; it has identical efficacy and safety to the original medicine but is typically less expensive. CT­P47 is in development as a possible tocilizumab biosimilar.Some patients prefer injections using an auto-injector (AI) rather than a pre-filled syringe (PFS), for reasons including ease of use and convenience. With an AI, medicine is delivered automatically by firmly pressing the device against the skin, whereas, with a PFS, a needle is inserted into the skin and medicine delivered by depressing the plunger. The injection of CT­P47 using a PFS has shown comparable pharmacokinetics (i.e., the uptake, metabolism and excretion of the drug by the body) and safety to tocilizumab. Therefore, if the pharmacokinetics and safety of CT­P47 administered via AI and PFS were shown to be similar, this might expand the choice of administration devices available to patients.In this study, 310 healthy adults received a single injection of CT­P47 via AI or PFS. Blood samples were taken over 43 days to analyze pharmacokinetics. The uptake, metabolism and elimination of CT­P47 by the body was similar when administered by each device, suggesting that CT­P47 can be administered by either AI or PFS.

Efficacy and safety of ongericimab given by prefilled syringe or autoinjector in primary hypercholesterolemia and mixed hyperlipidemia.

BACKGROUND AND AIMS: Limited evidence exist regarding the association between ongericimab, a novel recombinant humanized anti-PCSK9 monoclonal antibody, and primary hypercholesterolemia and mixed dyslipidemia. This study aimed to evaluate the efficacy and safety of ongericimab administered by prefilled syringe (PFS) or autoinjector (AI) in Chinese patients with primary hypercholesterolemia and mixed dyslipidemia on stable optimized lipid-lowering therapy. METHODS AND RESULTS: A total of 255 patients on stable optimized lipid-lowering therapy were randomized in a 2:1:2:1 ratio to receive PFS for the subcutaneous injection of ongericimab 150 mg every 2 weeks (Q2W) or a matching placebo, or AI for the subcutaneous injection of ongericimab 150 mg Q2W or a matching placebo. The primary efficacy endpoint was the percent change in low-density lipoprotein cholesterol (LDL-C) levels from baseline to week 12. Safety was also evaluated. At week 12, the least squares mean percent changes were -72.7% (3.9%) for PFS and -71.1% (3.8%) for AI (all P < 0.001) compared to respective matching placebo groups. Beneficial effects were also seen for all secondary lipid parameters, notably with robust reduction in Lp (a). Treatment-emergent adverse events (TEAEs) and serious AEs with ongericimab were reported in 46.2% and 2.4% of patients, compared to 44.2% and 3.5% with placebo. CONCLUSION: In Chinese patients with primary hypercholesterolemia and mixed dyslipidemia, a 12-week treatment regimen with ongericimab administered by PFS or AI significantly reduced LDL-C and other lipid parameters, proving to be safe and well tolerated. Patients experienced consistent effects from PFS or AI devices. CLINICAL TRIAL REGISTRATION: CTR20220027; January 11, 2022; http://www.chinadrugtrials.org.cn/index.html.

Vaccine preparation time, errors, satisfaction, and preference of prefilled syringes versus RSV vaccines requiring reconstitution: randomized, time and motion study.

AIM: The current study compared preparation time, errors, satisfaction, and preference for a prefilled syringe (PFS) versus two RSV vaccines requiring reconstitution (VRR1 and VRR2) in a randomized, single-blinded time and motion study. METHODS: Pharmacists, nurses, and pharmacy technicians were randomized to a preparation sequence of the three vaccines. Participants read instructions, then consecutively prepared the three vaccines with a 3-5-min washout period in between. Preparations were video recorded and reviewed by a trained pharmacist for preparation time and errors using predefined, vaccine-specific checklists. Participant demographics, satisfaction with vaccine preparation, and vaccine preference were recorded. Within-subjects analysis of variance was used to compare preparation time. Mixed-effects Poisson and ordered logistic regression models were used to compare the number of preparation errors and satisfaction scores, respectively. RESULTS: Sixty-three pharmacists (60%), nurses (35%), and pharmacy technicians (5%) participated at four sites in the United States. The least squares mean preparation time per dose for PFS was 141.8 s (95% CI = 156.8-126.7; p <.0001) faster than for VRR1, 103.6 s (95% CI = 118.7-88.5; p <.0001) faster than for VRR2, and 122.7 s (95% CI = 134.2-111.2; p <.0001) faster than the pooled VRRs. Overall satisfaction (combined "Very" and "Extremely") was 87.3% for PFS, 28.6% for VRR1, and 47.6% for VRR2. Most participants (81.0%) preferred the PFS vaccine. LIMITATIONS: The study is limited by the inability to completely blind observers. To minimize the effects of order, we utilized a 3-sequence block design; however, the order in which the vaccines were prepared may have affected outcomes. Participants were assessed once, whereas if repeated preparations were performed there may have been trained efficiencies gained for each vaccine. CONCLUSION: PFS vaccines can greatly simplify the vaccine preparation process, allowing administrators to prepare almost four times more doses per hour than with vial and syringe systems.

Estimated quantification of residual volume in vaccines supplies and its impact on the Brazilian health system.

Between 2017 and 2021, the Brazilian Unified Health System (BUHS) administered a total of 527,903,302 doses of immunizations. Each immunization results in the presence of a residual volume (RV) due to syringe dead space (DS). The International Organization for Standardization 7886-1 allows a DS of up to 0.07mL in sterile single-use hypodermic syringes with volumes less than 5mL. This study aims to quantify the DS of immunization devices used in Brazil, study the best combinations of needles and syringes to minimize RV, estimate the number of wasted doses from 2017 to 2021, and evaluate the impact on the BUHS. Pneumococcal 10 vaccine with a 25x6mm needle and a regular 1mL syringe exhibited a significantly higher average RV (0.0826mL) and waste rate (14.42%). It was observed that for some intramuscular vaccines, there is less waste when using a 20x5.5mm needle compared to a 25x6mm needle. The use of syringes with plunger stoppers that penetrate the syringe barrel, denoted as low dead space syringes, results in less RV and an estimated difference in the waste rate of approximately 10% compared to the regular syringe. The estimated number of wasted doses from 2017 to 2021 by BUHS is approximately 32 million doses.

Object and person tracking systems to enable extremity dosimetry in nuclear medicine using computational methods.

Nuclear medicine (NM) professionals are potentially exposed to high doses of ionising radiation, particularly in the skin of the hands. Ring dosimeters are used by the workers to ensure extremity doses are kept below the legal limits. However, ring dosimeters are often susceptible to large uncertainties, so it is difficult to ensure a correct measurement using the traditional occupational monitoring methods. An alternative solution is to calculate the absorbed dose by using Monte Carlo simulations. This method could reduce the uncertainty in dose calculation if the exact positions of the worker and the radiation source are represented in these simulations. In this study we present a set of computer vision and artificial intelligence algorithms that allow us to track the exact position of unshielded syringes and the hands of NM workers. We showcase a possible hardware configuration to acquire the necessary input data for the algorithms. And finally, we assess the tracking confidence of our software. The tracking accuracy achieved for the syringe detection was 57% and for the hand detection 98%.

Bacterial Contamination of Syringes and Fluids in Diagnostic and Interventional Neuroangiography.

(1) Background: Bacterial contamination has been shown to occur during angiographies, although data on its frequency and relevance are sparse. Our aim was to evaluate the incidence of bacterial contamination of syringes used under sterile conditions during neuroangiographies. We sought to differentiate between contamination of the outside of the syringes and the inside and to detect the frequency, extent and germ spectrum of bacterial contamination. (2) Methods: We prospectively collected 600 samples from 100 neuroangiographies. Per angiography, fluid samples from the three routinely used syringes as well as the syringes themselves were analyzed. We analyzed the frequency and extent of contamination and determined the germ spectrum. (3) Results: The majority of samples (56.9%) were contaminated. There was no angiography that showed no contamination (0%). The outer surfaces of the syringes were contaminated significantly more frequently and to a higher extent than the inner surfaces. Both the frequency and extent of contamination of the samples increased with longer duration of angiographic procedures. Most of the bacterial species were environmental or skin germs (87.7%). (4) Conclusions: Bacterial contamination is a frequent finding during neuroangiographies, although its clinical significance is believed to be small. Bacterial contamination increases with longer duration of angiographic procedures.

[Translated article] Syringes for intraocular administration: A systematic review.

OBJECTIVE: The off-label use in clinical practice of non-approved syringes for intravitreal drug administration has resulted in the detection of silicone oil drops in the vitreous of some patients. This situation derives from the lack of approved syringes for intraocular use in the Spanish market. The aim of this work is to review the use of syringes for intraocular administration, as well as to search for alternatives that meet the legal requirements for these unmet needs. METHOD: A systematic review was performed following the PRISMA 2020 guidelines by searching PubMed with the descriptors: (silicone) AND (syringes) AND ((intraocular) OR (intravitreal)) and filtering all existing publications from January 2006 to December 2023, including all those articles dealing with silicone oil release in intravitreal injections and analysing the possible consequences. RESULTS: Sixty-eight results were found, 23 of which were excluded because they did not deal with the subject under study, leaving a total of 45 articles for the systematic review. These were classified according to the conclusions obtained in 4 groups: the adverse reactions produced by silicone; the administration technique; the physicochemical aspects of silicone release; and the characteristics of the medical device. After reviewing the current manufacturers and technical data sheets of commercialised syringes, the existing syringes for this use have been collected, finding 2 that will probably be commercialised in Spain at the beginning of 2024: Zero Residual™ 0.2 ml SiO-free and VitreJect® Ophthalmic. CONCLUSIONS: From the results obtained, it can be interpreted that the use of syringes and needles with silicone for intravitreal use is a concern for health professionals due to the implications and consequences that may arise in patients, the most important being adverse reactions, so it is necessary to have silicone-free syringes on the market that are specific for intraocular use. Safety and legality in the use of intraocular syringes and needles is essential to guarantee ocular integrity and patient health.

Successful implementation of safe practice for adult intravenous push medication in a tertiary care hospital: determination of stability of four intravenous antibiotics in syringes.

In 2017, a severe shortage of infusion bags resulted in a paradigm change in medication administration practice from intermittent infusion to intravenous push. The Institute for Safe Medication Practices proposed safe practice guidelines for adult intravenous push medications. A different study showed that ready-to-administer medication prepared in the sterile area of a pharmacy reduces the risk of harm, nurses' time for medication administration and the cost of medications. Based on the recommendation of the Institute for Safe Medication Practices, we decided to conduct a pilot study on the implementation of sterile compounding and administration of intravenous push medication in adult patients admitted to the hospital. In the study, the stability of five intravenous push antibiotic syringes was also determined in the syringes.

Loss of micropollutants on syringe filters during sample filtration: Machine learning approach for selecting appropriate filters.

Prefiltration before chromatographic analysis is critical in the monitoring of environmental micropollutants (MPs). However, in an aqueous matrix, such monitoring often leads to out-of-specification results owing to the loss of MPs on syringe filters. Therefore, this study investigated the loss of seventy MPs on eight different syringe filters by employing Random Forest, a machine learning algorithm. The results indicate that the loss of MPs during filtration is filter specific, with glass microfiber and polytetrafluoroethylene filters being the most effective (<20%) compared with nylon (>90%) and others (regenerated-cellulose, polyethersulfone, polyvinylidene difluoride, cellulose acetate, and polypropylene). The Random Forest classifier showed outstanding performance (accuracy range 0.81-0.95) for determining whether the loss of MPs on filters exceeded 20%. Important factors in this classification were analyzed using the SHapley Additive exPlanation value and Kruskal-Wallis test. The results show that the physicochemical properties (LogKow/LogD, pKa, functional groups, and charges) of MPs are more important than the operational parameters (sample volume, filter pore size, diameter, and flow rate) in determining the loss of most MPs on syringe filters. However, other important factors such as the implications of the roles of pH for nylon and pre-rinsing for PTFE syringe filters should not be ignored. Overall, this study provides a systematic framework for understanding the behavior of various MP classes and their potential losses on syringe filters.

An evaluation of a Stenotrophomonas maltophilia outbreak due to commercial arterial blood gas collection kit.

BACKGROUND: Stenotrophomonas maltophilia is a gram-negative bacterium that can cause hospital infections and outbreaks within hospitals. This study aimed to evaluate an outbreak of Stenotrophomonas maltophilia, caused by ready-to-use commercial syringes containing liquid lithium and heparin for arterial blood gas collection in a university hospital. METHODS: Upon detecting an increase in Stenotrophomonas maltophilia growth in blood cultures between 15.09.2021 and 19.11.2021, an outbreak analysis and a case-control study (52 patients for the case group, 56 patients for the control group) were performed considering risk factors for bacteremia. Samples from possible foci for bacteremia were also cultured. Growing bacteria were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The genetic linkage and clonal relationship isolates were investigated with pulsed-field gel electrophoresis (PFGE) in the reference laboratory. RESULTS: In the case-control study, the odds ratio for the central venous catheter [3.38 (95% confidence interval [CI]: 1.444, 8.705 ; p = 0.006)], for surgery [3.387 (95% confidence interval [CI]: 1.370, 8.373 ; p = 0.008)] and for arterial blood gas collection history [18.584 (95% confidence interval [CI]:4.086, 84.197; p < 0.001)] were identified as significant risk factors. Stenotrophomonas maltophilia growth was found in ready-to-use commercial syringes used for arterial blood gas collection. Molecular analysis showed that the growths in the samples taken from commercial syringes and the growths from blood cultures were the same. It was decided that the epidemic occurred because the method for sterilization of heparinized liquid preparations were not suitable. After discontinuing the use of the kits with this lot number, the outbreak was brought under control. CONCLUSIONS: According to our results, disposable or sterile medical equipment should be included as a risk factor in outbreak analyses. The method by which injectors containing liquids, such as heparin, are sterilized should be reviewed. Our study also revealed the importance of the cooperation of the infection control team with the microbiology laboratory.

Syringe reuse among people who inject drugs in rural Appalachian Kentucky.

BACKGROUND: Personal syringe reuse (i.e., reuse of one's own syringes) can place people who inject drugs at increased risk for infectious disease but has received relatively little attention in published literature. The purpose of this study is to identify factors associated with syringe reuse among people who inject drugs in rural Kentucky. METHODS: Participants (n = 238) completed interviewer-administered questionnaires on syringe reuse and demographic, behavioral, and service access characteristics. Unadjusted negative binomial regression with cluster-robust standard errors was used to model the associations with a logged offset for number of injections in the past 30 days. RESULTS: The average age of the sample was 35 and 59.7 % were male. Most participants (77.7 %) reused syringes at least once in the past 30 days, using each syringe a median of three times. Reuse was higher among those who were older and reported a higher street price for syringes. Syringe reuse was lower among people who were within walking distance to a syringe service program (SSP) and who obtained most of their syringes from SSPs or pharmacies. CONCLUSION: Syringe reuse among people who inject drugs in rural Kentucky is common. However, these data suggest that increased access to syringes from SSPs and pharmacies, as well as policy-level interventions that reduce street syringe price, might reduce syringe reuse and related harms.

Contrast-enhanced transcranial Doppler for the detection of right-to-left shunt: A new provocation method with a syringe-modified Valsalva maneuver.

BACKGROUND: Contrast-enhanced transcranial Doppler (cTCD) study has been established as one of the most common investigations for detecting right-to-left shunt (RLS). Although the conventional Valsalva maneuver (c-VM) has been used to increase the sensitivity of cTCD for RLS, efforts are still needed to improve the detection rate further. We proposed a new provocation method with a syringe-modified Valsalva maneuver (sm-VM) during cTCD and compared the efficacy of this strategy with cTCD measured at resting and with the provocation of c-VM. METHODS: Consecutive patients with suspicion of RLS who underwent cTCD in our institution between September 27, 2021, and April 1, 2022, were included in this study. Examination of cTCD was performed separately at the resting state and provoked with c-VM and sm-VM. The overall proportion of patients with RLS and their distribution with different RLS grades were compared. RESULTS: A total of 389 patients (mean age: 49.37 years, male: 52.2%) were included in this study. The positive rate for RLS was significantly higher for cTCD detected with sm-VM than those detected at resting state and with c-VM (46.8% vs. 21.6% and 34.2%, all p < .05). Besides, cTCD detected with sm-VM was also associated with a higher proportion of patients with grade III RLS than those detected at resting state and with c-VM (11.3% vs. 1.8% and 0%, all p < .05). CONCLUSIONS: Compared to cTCD detected at resting state and with c-VM, cTCD with sm-VM could further increase the positive detection rate of RLS.

Novel sample double dilution calibration method for determination of lithium in biological samples using automatic flow system with in-syringe reaction.

A novel sample double dilution calibration method (SDDCM) and an automatic flow system with in-syringe reaction and spectrophotometric detection were developed for determining lithium in biological samples. The method is based on the reaction of lithium with Thorin in an alkaline medium and the signal was measured at 480 nm. The reaction was performed simultaneously for both standards and samples in three syringes of the automatic flow system. The method was validated and successfully applied to the determination of lithium in synthetic and pharmaceutical samples, with results consistent with the ICP OES method. The novel calibration method, developed for the determination of lithium in biological samples, uses a sample with two dilution degrees. Using the method, the concentration of the analyte is determined by relating the signal for a less diluted sample to the calibration plot for a more diluted sample and vice versa. The implementation of the calibration method was facilitated by preparing solutions directly in the flow system. The use of two sample dilutions makes it possible to determine the analyte in the sample without preliminary preparation. Moreover, obtaining two results based on signals for a sample diluted to different degrees allows them to be verified for accuracy. The proposed approach was successfully verified by the determination of lithium in certified reference materials of blood serum and urine. Using the developed method lithium was determined within the concentration range of 0.06-1.5 mg L-1, with precision (CV, %) less than 6.7, and accuracy (RE, %) better than 6.9. The detection limit was 0.03 mg L-1.