Minimum Effective Concentration Research Articles

MODL-14. TARGETING GL1/GL2-DNMT1-UHRF1 EPIGENETIC COMPLEX DISRUPTION VIA BET INHIBITION IMPAIRS SHH MB DEVELOPMENT

Abstract BACKGROUND Sonic Hedgehog Medulloblastoma (SHH MB) shares 30% among all molecular subtypes of medulloblastomas (MBs). Constitutive activation of SHH signaling in the cerebellum’s granular cell precursors (GCPs) is critical for this MB development. When SHH receptor PATCHED-1 (PTCH1) is mutated, stimulation of this receptor by SHH ligand binding leads to derepression of heterotrimeric GTP-binding protein–coupled receptor Smoothened (SMO) eventually altering the activity, location, and stability of the three downstream glioma associated oncogene (GLI) family members: GLI1, GLI2, and GLI3. GLI1 and GLI2 mostly function as transcriptional activators, while GLI3 mainly plays a repressor role. The bromodomain and extra-terminal domain (BET) family of proteins comprises four conserved members (Brd2, Brd3, Brd4, and Brdt), which are critical regulators of GLI1 and GLI2-mediated transcription. METHODS In the present study, we pharmacologically inhibited BETs with a previously described BET inhibitor, BMS986158, and a novel BET inhibitor, UM002, discovered by our lab. We treated human SHH MB cells (ONS76 cells) in vitro and ex vivo in mouse SHH MB cells (from Ptch1 conditional knockout mice) with minimum effective concentrations of these inhibitors. We screened for GLI1/GLI2-DNMT1-UHRF1 epigenetic complex components expressions by immunoblotting and assessed the effectiveness of inhibiting their interactions by performing PLA assays. RESULTS In this study, we show that pharmacological inhibition of BETs leads to attenuated GLI1 and GLI2 levels. This GLI1 and GLI2 inhibition eventually disrupts the previously reported GL1/GL2, DNMT1-UHRF1 epigenetic complex, which is crucial for SHH MB development. A previously described BET inhibitor, BMS986158, and a novel BET inhibitor, UM002, synthesized and characterized by our lab can inhibit BETs. This could be a potential therapeutic approach targeting GLI-associated epigenetic complexes to treat SHH medulloblastoma.

Insectoacaricide activity of 5% D-cyphenothrin Emulsion against argasid ticks and biting lice

The purpose of the research is to evaluate the insectoacaricidal activity of the drug 5% D-cyphenothrin Emulsion against argasid ticks and biting lice in different concentrations.Materials and methods. We carried out a parasitological examination of an open-type cinderblock poultry building in peasant household BUGLEN-2 (the Republic of Dagestan) using the avian ectoparasite collecting methods of B. A. Frolov (1975). The studies were performed using procedures outlined in the studies by A. A. Nepoklonov and G. A. Talanov (1973), M. V. Arisov and I. A. Arkhipov (2018) as modified. In the Laboratory of Ectoparasitosis in the VNIIP – FSC VIEV, the acaricidal activity of 5% D-cyphenothrin Emulsion was evaluated against argasid ticks and LD50 and LD95 were determined. The insecticidal activity of the studied drug in different concentrations against the biting lice Menopon gallinae and Menacanthus stramineus was studied on naturally infected chickens that were kept on the farm. Parasitic arthropods were identified to species using identification guides by I. G. Galuzo (1957), N. A. Fillipova (1966) and D. I. Blagoveshchensky (1940).Results and discussion. In laboratory, we observed rapid death of argasid ticks within 30 minutes after their contact with absorbent paper impregnated with 0.005% and 0.05% concentrations of the studied drug. In the assessment of the 5% D-cyphenothrin Emulsion insecticidal activity against biting lice of two species Menopon gallinae and Menacanthus stramineus on naturally infected chickens, we observed the death of parasitic insects after 24 hours on the birds treated with a 0.005% emulsion. Thus, the minimum effective concentration of 0.005 % of the study drug, 5% D-cyphenothrin Emulsion, was determined for the above parasitic arthropods.

Identification of Xuanfei Baidu granule constituents by liquid chromatography-quadruple-time-of-flight-mass spectrometry and its anti-inflammatory active constituents using a lipopolysaccharide-induced RAW264.7 cell model.

The Xuanfei Baidu (XFBD) prescription, a traditional Chinese medicine prescription, has demonstrated significant anti-inflammatory activities; however, the number of its reported constituents is limited, and its anti-inflammatory constituents are unclear. In this study, the constituents of XFBD granule, a granule dosage of XFBD prescription, were thoroughly examined in vitro and in vivo using liquid chromatography-quadruple-time-of-flight-mass spectrometry, and the anti-inflammatory constituents were screened. A total of 214 constituents were identified from the XFBD granule, 62 of which were confirmed via comparison with reference standards. After intragastric administration of XFBD granule, 63 and 28 constituents were absorbed into the rat sera and lungs in prototype form, respectively. XFBD granule and XFBD-containing serum were found to significantly reduce nitric oxide (NO) and interleukin-6 (IL-6) secretion in lipopolysaccharide-induced RAW264.7 cells. Five anti-inflammatory constituents (verbasoside, scutellarin, luteolin, apigenin, and pogostone) were found to reduce the concentration of NO and IL-6 in a dose-dependent manner. Moreover, the combination of these five constituents could significantly reduce NO secretion even when the concentration of each constituent was two to three orders of magnitude lower than their individual minimum effective concentrations. Overall, this study provides a valuable reference for the discovery of effective constituents from the XFBD granule.

The 90% minimum effective concentration of ropivacaine for ultrasound‐guided interscalene brachial plexus block in children aged 1–10 years: A biased coin design up‐and‐down sequential allocation trial

AbstractRopivacaine is a commonly used local anesthetic for brachial plexus blocks in children, but the minimum effective dose of ropivacaine for interscalene brachial plexus blocks has not been reported. The aim of this study was to determine the 90% minimum effective concentration (MEC90) of ropivacaine for an ultrasound‐guided interscalene brachial plexus block (ISB). A total of 155 patients, aged from 1 to 10 years, underwent unilateral surgical procedures on areas of the upper extremity not innervated by the ulnar nerve. The biased coin design up‐and‐down sequential method (BCD‐UMD) was used to determine the MEC90 of ropivacaine for ultrasound‐guided ISB. In our study, the initial concentration of ropivacaine was 0.07% in the toddler group and 0.09% in the preschool and school‐age groups. During the trial, the concentration of ropivacaine for each subsequent patient was determined by the blocking effect of the previous patient. In case of failure, the concentration for the next patient was increased by 0.01%. Otherwise, the concentration was either decreased by 0.01%, with a probability of 0.11, or kept the same, with a probability of 0.89. Overall, the MEC90 of ropivacaine was 0.104% (95% confidence interval (CI), 0.070%–0.106%) in the toddler group, 0.114% (95% CI, 0.090%–0.117%) in the preschool group, and 0.133% (95% CI, 0.099%–0.136%) in the school‐age group. No adverse events occurred. Our study showed that lower concentrations of ropivacaine could provide effective nerve blocks and reduce the risk of local anesthetics.

Tenofovir, emtricitabine, lamivudine and dolutegravir concentrations in plasma and urine following drug intake cessation in a randomized controlled directly observed pharmacokinetic trial to aid point-of-care testing.

Poor adherence to ART and pre-exposure prophylaxis (PrEP) can impact patient and public health. Point-of-care testing (POCT) may aid monitoring and adherence interventions. We report the pharmacokinetics of tenofovir [dosed as tenofovir disoproxil (TDF) and tenofovir alafenamide (TAF)], emtricitabine (FTC), lamivudine (3TC) and dolutegravir (DTG) in plasma and urine following drug cessation to evaluate adherence targets in urine for POCT. Subjects were randomized (1:1) to receive DTG/FTC/TAF or DTG/3TC/TDF for 15 days. Plasma and spot urine were collected on Day 15 (0-336 h post final dose). Drug concentrations were quantified using LC-MS, and non-linear mixed-effects models applied to determine drug disposition between matrices and relationship with relevant plasma [dolutegravir protein-adjusted 90% inhibitory concentration (PA-IC90 = 64 ng/mL) and minimum effective concentration (MEC = 324 ng/mL)] and urinary thresholds [tenofovir disoproxil fumarate 1500 ng/mL]. Of 30 individuals enrolled, 29 were included (72% female at birth, 90% Caucasian). Median (range) predicted time to plasma dolutegravir PA-IC90 and MEC were 83.5 (41.0-152) and 49.0 h (23.7-78.9), corresponding to geometric mean (90%) urine concentrations of 5.42 (4.37-6.46) and 27.4 ng/mL (22.1-32.7). Tenofovir in urine reached 1500 ng/mL by 101 h (58.6-205) with an equivalent plasma concentration of 6.20 ng/mL (4.21-8.18). These data support use of a urinary tenofovir threshold of <1500 ng/mL (tenofovir disoproxil fumarate-based regimens) as a marker of three or more missed doses for a POCT platform. However, due to low dolutegravir concentrations in urine, POCT would be limited to a readout of recent dolutegravir intake (one missed dose).

Management of the Drug-Drug Interactions Between Valproic Acid and Dolutegravir-A Case Study.

Preliminary evidence shows that concomitant administration of valproic acid can reduce the exposure to dolutegravir with limited clinical impacts. Here, we describe a male living with HIV who experienced a drastic reduction in dolutegravir trough concentrations a few weeks after starting valproic acid treatment as identified by therapeutic drug monitoring. Concomitantly, pharmacists recommended a supplementation of magnesium to improve insomnia. A 62-year-old man with HIV on antiretroviral therapy with dolutegravir and lamivudine recently added valproic acid to clonazepam and sertraline to treat severe sleep disturbances. An 84% reduction in dolutegravir trough concentrations was observed compared with the previous outpatient visit (418 versus 2714 ng/mL), with values close to the minimum effective drug concentration (300 ng/mL). Considering this, we strongly discourage the use of magnesium. We are confident that our findings can contribute to a better understanding of the clinical problems that infectious disease physicians encounter in their daily management of people with HIV and how therapeutic drug monitoring may add value in this context. This case also highlights the importance of multidisciplinary services for the optimal management of polypharmacy in people with HIV.

Novel aurone-derived piperazine sulfonamides: Development and mechanisms of action as immunostimulants against plant bacterial diseases

Bacterial diseases pose a significant threat to the sustainable production of crops. Given the unsatisfactory performance and poor eco-compatibility of conventional bactericides, here we present a series of newly structured bactericides that are inspiringly designed by aurone found in plants of the Asteraceae family. These aurone-derived compounds contain piperazine sulfonamide motifs and have shown promising in vitro performance against Xanthomonas oryzae pv. oryzae, Xanthomonas oryzae pv. oryzicola and Xanthomonas axonopodis pv. citri, in particular, compound II23 achieved minimum half-maximal effective concentrations of 1.06, 0.89, and 1.78 μg/mL, respectively. In vivo experiments conducted in a greenhouse environment further revealed that II23 offers substantial protective and curative effects ranging between 68.93 and 70.29% for rice bacterial leaf streak and 53.17–64.43% for citrus bacterial canker, which stands in activity compared with lead compound aurone and commercial thiodiazole copper. Additional physiological and biochemical analyses, coupled with transcriptomics, have verified that II23 enhances defense enzyme activities and chlorophyll levels in rice. Significantly, it also stimulates the accumulation of abscisic acid (ABA) and upregulates the expression of key genes OsPYL/RCAR5, OsBIPP2C1, and OsABF1, thereby activating the ABA signaling pathway in rice plants under biological stress from bacterial infections.

Pharmacokinetics of Tranexamic Acid (TXA) Delivered by Expeditious Routes in a Swine Model of Polytrauma and Hemorrhagic Shock

Objective Hemorrhage is the leading cause of preventable death in civilian trauma centers and on the battlefield. One of the emerging treatment options for hemorrhage in austere environments is tranexamic acid (TXA). However, the landscape is not amenable to the current delivery standard. This study compared the pharmacokinetics of TXA via a standard 10-minute intravenous infusion (IV infusion), intravenous rapid push over 10 s (IV push), and intramuscular injection (IM) in a swine polytrauma and hemorrhagic shock model (trauma group) compared to uninjured controls (control group). Methods Thirty swine were randomized to the trauma or control group. Following anesthesia, the trauma group experienced a simulated blast injury and 40% controlled hemorrhage. Subjects in both groups were then randomized to receive 1 g/10 mL TXA via IV infusion, IV push, or IM. Animals were monitored for four hours with serial blood sampling. Serum TXA concentrations were measured by liquid chromatography with tandem mass spectrometry (LC-MS/MS) and analyzed. Results The time to maximum TXA concentration (Tmax) was not affected by trauma in IV infusion or IV push, but was affected in the IM administration with Tmax significantly slower than the control group (p = 0.016). The minimum effective serum concentration of TXA (Ceff, 10 µg/mL) was reached in less than one minute with IV infusion and instantaneously with IV push. Despite lower bioavailability, the time to reach Ceff (Teff) was achieved via IM administration in less than 10 min for both groups (6.4 min trauma vs. 2.1 min control). Conclusions In austere prehospital environments, an alternative to intravenous infusion of a life-saving medication is desired. Administration of TXA via all three methods reached the level needed to cause substantial inhibition of fibrinolysis within 10 min. The IV push method showed similar pharmacokinetics to IV infusion of TXA but can be delivered quickly without sacrificing an access site for 10 min.

Galectin-8-like isoform X1 mediates antibacterial, antiviral, and antioxidant responses in red-lip mullet (Planiliza haematocheilus) through positive modulation of pro-inflammatory cytokine, chemokine, and enzymatic antioxidant activity

Galectin 8 belongs to the tandem repeat subclass of the galectin superfamily. It possesses two homologous carbohydrate recognition domains linked by a short peptide and preferentially binds to β-galactoside-containing glycol-conjugates in a calcium-independent manner. This study identified Galectin-8-like isoform X1 (PhGal8X1) from red-lip mullet (Planiliza haematocheilus) and investigated its role in regulating fish immunity. The open reading frame of PhGal8X1 was 918bp, encoding a soluble protein of 305 amino acids. The protein had a theoretical isoelectric (pI) point of 7.7 and an estimated molecular weight of 34.078 kDa. PhGal8X1 was expressed in various tissues of the fish, with prominent levels in the brain, stomach, and intestine. PhGal8X1 expression was significantly (p < 0.05) induced in the blood and spleen upon challenge with different immune stimuli, including polyinosinic:polycytidylic acid, lipopolysaccharide, and Lactococcus garvieae. The recombinant PhGal8X1 protein demonstrated agglutination activity towards various bacterial pathogens at a minimum effective concentration of 50 μg/mL or 100 μg/mL. Subcellular localization observations revealed that PhGal8X1 was primarily localized in the cytoplasm. PhGal8X1 overexpression in fathead minnow cells significantly (p < 0.05) inhibited viral hemorrhagic septicemia virus (VHSV) replication. The expression levels of four proinflammatory cytokines and two chemokines were significantly (p < 0.05) upregulated in PhGal8X1 overexpressing cells in response to VHSV infection. Furthermore, overexpression of PhGal8X1 exhibited protective effects against oxidative stress induced by H2O2 through the upregulation of antioxidant enzymes. Taken together, these findings provide compelling evidence that PhGal8X1 plays a crucial role in enhancing innate immunity and promoting cell survival through effective regulation of antibacterial, antiviral, and antioxidant defense mechanisms in red-lip mullet.

Use of quantitative in vitro to in vivo extrapolation (QIVIVE) for the assessment of non-combustible next-generation product aerosols.

With the use of in vitro new approach methodologies (NAMs) for the assessment of non-combustible next-generation nicotine delivery products, new extrapolation methods will also be required to interpret and contextualize the physiological relevance of these results. Quantitative in vitro to in vivo extrapolation (QIVIVE) can translate in vitro concentrations into in-life exposures with physiologically-based pharmacokinetic (PBPK) modelling and provide estimates of the likelihood of harmful effects from expected exposures. A major challenge for evaluating inhalation toxicology is an accurate assessment of the delivered dose to the surface of the cells and the internalized dose. To estimate this, we ran the multiple-path particle dosimetry (MPPD) model to characterize particle deposition in the respiratory tract and developed a PBPK model for nicotine that was validated with human clinical trial data for cigarettes. Finally, we estimated a Human Equivalent Concentration (HEC) and predicted plasma concentrations based on the minimum effective concentration (MEC) derived after acute exposure of BEAS-2B cells to cigarette smoke (1R6F), or heated tobacco product (HTP) aerosol at the air liquid interface (ALI). The MPPD-PBPK model predicted the in vivo data from clinical studies within a factor of two, indicating good agreement as noted by WHO International Programme on Chemical Safety (2010) guidance. We then used QIVIVE to derive the exposure concentration (HEC) that matched the estimated in vitro deposition point of departure (POD) (MEC cigarette = 0.38 puffs or 11.6µg nicotine, HTP = 22.9 puffs or 125.6µg nicotine) and subsequently derived the equivalent human plasma concentrations. Results indicate that for the 1R6F cigarette, inhaling 1/6th of a stick would be required to induce the same effects observed in vitro, in vivo. Whereas, for HTP it would be necessary to consume 3 sticks simultaneously to induce in vivo the effects observed in vitro. This data further demonstrates the reduced physiological potency potential of HTP aerosol compared to cigarette smoke. The QIVIVE approach demonstrates great promise in assisting human health risk assessments, however, further optimization and standardization are required for the substantiation of a meaningful contribution to tobacco harm reduction by alternative nicotine delivery products.

Pharmacological Screening of Cholinergic Drugs Using &lt;i&gt;Daphnia magna Straus&lt;/i&gt; Hydrobionts as a Biological Test Object

This work presents the results of primary pharmacological screening of anticholinergic drugs and comparative evaluation of their specific activity in equitoxic concentrations using Daphnia magna Straus hydrobionts as a biological test object. We determine the protective index and the minimum effective concentration in terms of preventing atypical motor hyperactivity of pharmacological substances when poisoning with a reversible acetylcholinesterase inhibitor. On the basis of the results obtained, the list of promising candidates for further research in warm-blooded animals is extended by all of the anticholinergic drugs previously selected in experiments on mammals.

A new Turkish pharmacokinetics software program for therapeutic drug monitoring of theophylline

In this study, it was aimed to develop a Turkish software with pharmacokinetic (PK) data for therapeutic drug monitoring and IV dose adjustment of narrow therapeutic index theophylline. The study involved three groups, each comprising two rabbits The dose required for the target concentration (15µg/mL) was calculated with the developed program according to the weight of the rabbits in the first group. Blood samples taken at certain times were analyzed by validated HPLC method to calculate the elimination rate constant (ke) after IV bolus administration. The r2 values for ke were found to be 0.86 and 0.95. The second dose calculated according to revised PK findings was administered and blood samples were taken. When the analyzed results and theoretical results were compared, the deviation was found to be 5.53% and 8.795%. The findings were taken as the population PK for other applications. IV multiple dose bolus and IV fast-slow combined infusion were administered to the second group and the third group, respectively. The results obtained from the analysis of blood samples taken at the times determined according to the application were compared with the theoretical results. As a result, although there is a high difference between theory and practice at low concentrations, there is very little variation at high concentrations. By using this program, it has been achieved to keep theophylline at the desired level without reaching the minimum toxic concentration and without falling below the minimum effective concentration. It is thought that deviations will be reduced with larger samples.

Diabetic Neuropathy and Minimum Effective Anesthetic Concentration of Mepivacaine for Axillary Brachial Plexus Block: A Prospective Observational Study.

Nerves in patients with diabetic neuropathy (DN) show increased susceptibility to local anesthetics, potentially requiring a decreased dose. We investigated whether the minimum effective anesthetic concentration (MEAC) of mepivacaine for successful axillary block is lower in patients with DN than in those without. This prospective observational study included patients with DN (n = 22) and without diabetes (n = 22) at a tertiary care center. Patients received an ultrasound-guided axillary block with 30 mL of mepivacaine for anesthesia. The mepivacaine concentration used in each patient was calculated using Dixon's up-and-down method. A block was considered successful if all four sensory nerves had a score of 1 or 2 within 30 min with no pain during surgery. The primary outcome was the MEAC of mepivacaine, and the secondary outcomes included the minimal nerve stimulation intensity for the musculocutaneous nerve and the occurrence of adverse events. The MEAC50 was 0.55% (95% CI 0.33-0.77%) in patients without diabetes and 0.58% (95% CI 0.39-0.77%) in patients with DN (p = 0.837). The MEAC90 was 0.98% (95% CI 0.54-1.42%) in patients without diabetes and 0.96% (95% CI 0.57-1.35%) in patients with DN (p = 0.949). The stimulation threshold for the musculocutaneous nerve was significantly different between groups (0.49 mA vs. 0.19 mA for patients with vs. without diabetes; p = 0.002). In conclusion, the MEAC of mepivacaine for a successful axillary block is not lower in patients with DN.

Extending the dosing intervals of nivolumab: model-based simulations in unselected cancer patients.

Reducing nivolumab dose intensity could increase patients' life quality and decrease the financial burden while maintaining efficacy. The aims of this study were to develop a population PK model of nivolumab based on data from unselected metastatic cancer patients and to simulate extended-interval regimens allowing to maintain minimal effective plasma concentrations (MEPC). Concentration-time data (992 plasma nivolumab concentrations, 364 patients) were modeled using a two-compartment model with linear elimination clearance in Monolix software. Extended-interval regimens allowing to maintain steady-state trough concentrations (Cmin,ss) above the MEPC of 2.5 mg/L or 1.5 mg/L in >90% of patients were simulated. Increasing 3-times the dosing interval from 240 mg every two weeks (Q2W) to Q6W and 2-times from 480 mg Q4W to Q8W resulted in Cmin,ss above 2.5 mg/L in 95.8% and 95.4% of patients, respectively. 240 mg Q8W and 480 mg Q10W resulted in Cmin,ss above 1.5 mg/L in 91.0% and 91.8% of patients, respectively. Selection of a 240 mg Q6W regimen would decrease by 3-fold the annual treatment costs compared to standard regimen of 240 mg Q2W (from 78,744€ to 26,248€ in France). Clinical trials are warranted to confirm the non-inferiority of extended-interval compared to standard regimen.

Parabens promotes invasive properties of multiple human cells: A potential cancer-associated adverse outcome pathway

Parabens are esters of p-hydroxybenzoic acid, which have been used as preservatives and considered safe for nearly a century, until the last two decades when concerns began to be raised about their association with cancers. Knowledge of the mode of action of parabens on the metastatic properties of different cancer cells is still very limited. In the present study, we investigated the effects of methylparaben (MP) and propylparaben (PP) on cell invasion and/or migration in multiple human cancerous and noncancerous cells, including hepatocellular carcinoma cells (HepG2), cervical carcinoma cells (HeLa), breast carcinoma cells (MCF-7), and human placental trophoblasts (HTR-8/SVneo). MP and PP at concentrations in a range of 5–500 μg/L significantly promoted the invasion of four cell lines, with a minimum effective concentration of 5 μg/L. MP and PP up-regulated the expression levels and enzymatic activities of matrix metalloproteinase 2 and 9 (MMP2 and MMP9), as well as altered the expression of the tissue inhibitors of metalloproteinase 1 and 2 (TIMP1 and TIMP2) in four cell lines, suggesting MMPs/TIMPs as potential key events (KEs) for paraben-induced cell invasion. Activation of the p38 mitogen-activated protein kinase (p38 MAPK) and c-Jun N-terminal protein kinases 1/2 (JNK1/2) signaling pathways was required for MP- and PP-promoted invasion of four cell lines, suggesting MAPK signaling pathways as candidates for KEs in cancer or noncancerous cells response to paraben exposure. This study showed for the first time that the two widely used parabens, MP and PP, promoted invasive capacity of multiple human cells through a common mode of action. This study provides evidence for the establishment of a potential cancer-associated AOP for parabens based on pathway-specific mechanism(s), which contributes towards assessing the health risks of these environmental chemicals.

Abstract 7184: Simulating extended dosing intervals for atezolizumab: A comparative analysis between NONMEM and Pumas

Abstract The initially approved dosage regimens of 840 mg every 2 weeks, 1200 mg every 3 weeks, and 1680 mg every 4 weeks are considered excessive concerning the specified minimum effective concentration of 6 ug/mL and the significant exposure-response relationship with Adverse Events of Special Interest (AESI). Our previous research, demonstrated through simulation, indicated that an extended-interval dosing regimen (840 mg every 6 weeks) after two standard loading doses maintained efficacy with a nonsignificant exposure-response relationship with AESI.In alignment with the FDA's initiative "Project Optimus," which aims to optimize drug dosing for improved therapeutic outcomes, we explore alternative dosage regimens for atezolizumab. Through a comparison of the traditional 30-year-old industry standard NONMEM software and the recently developed PumasAI software, we simulate these regimens, utilizing our previously published article as a benchmark. Given the rapid evolution of artificial intelligence (AI) and machine learning, it is crucial for pharmacokinetic modeling to adapt and leverage these advancements. We anticipate that this paper will contribute to the integration of AI and machine learning software in pharmacokinetic analysis, aligning with the goals of "Project Optimus" to ensure that drug concentrations are optimized for efficacy and safety. Table 1: Comparative Summary of Simulated Pharmacokinetic Parameters: Pumas vs. NONMEM Pumas NONMEM Regimen Cycle Week Cmax (ug/mL) Cmax (ug/mL) Cmax (ug/mL) Cmax (ug/mL) Cmin (ug/mL) Weekly AUC (ug*day/mL) 1200 mg q3w 1st 3 384(278-533) 64.1(31.4-112) 919(640-1290) 394 (278-559) 75.6 (44.5-121) 1003 (755-1342) 7th 21 541(371-795) 146(53.8-349) 1750(977-3210) 583 (414-847) 180 (75.9-396) 2014 (1169-3535) 840 mg q2w x2, 840 mg q6w 1st 2 270(195-379) 61.6(35.5-100) 775(570-1085) 275 (184-397) 71.2 (46.4-108) 834 (620-1131) 7th 38 314(221-448) 33.6(8.8-127) 650(357-1375) 336 (235-487) 46.9 (13.5-150) 774 (441-1562) 1200 mg q3w x2, 840 mg q6w 1st 3 384(278-533) 64.1(31.4-112) 919(640-1290) 394 (278-559) 75.6 (44.5-121) 1003(755-1342) 7th 39 316(224-459) 36.0(8.4-129) 670(340-1406) 327 (217-492) 46.6 (13.4-157) 763 (411-1594) 1680 mg q4w x2, 840 mg q6w 1st 4 545(380-779) 63.1(26.9-122) 1096(735-1555) 552 (375-793) 78.1 (40.7-135) 1203(869-1651) 7th 40 318(222-469) 33.9(7.7-126) 657(343-1385) 332 (227-491) 46.5 (13.6-140) 771 (436-1464) Citation Format: Francis Bateman, Oluwatobi Arisa, Natalia Corvalan Cabanas, Yi Zeng, Cody Peer, Keith Schmidt, William Douglas Figg. Simulating extended dosing intervals for atezolizumab: A comparative analysis between NONMEM and Pumas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7184.

The minimum effective concentration (MEC90) of bupivacaine for an ultrasound-guided suprainguinal fascia iliaca compartment block for analgesia in knee surgery: a dose-finding study.

In recent years, the suprainguinal fascia iliaca compartment block (SFICB) has become more common in clinical practice. This assessor-blinded dose-finding study aimed to determine the minimum effective concentration (MEC90, MEC95) of bupivacaine for a single-injection SFICB in patients undergoing arthroscopic anterior cruciate ligament repair. This prospective study was conducted at a tertiary hospital (postoperative recovery room and ward). The SFICB was performed as a postsurgical intervention after spinal anesthesia. Seventy patients were allocated using the biased-coin design up-and-down sequential method. The ultrasound-guided SFICB was performed using different bupivacaine concentrations, and standard multimodal analgesia was administered to all patients. Block success was defined as the absence of pain or presence of only tactile sensation during the pinprick test conducted on the anterior and lateral regions of the mid-thigh six hours postoperatively. According to isotonic regression and bootstrap CIs, the MEC90 value of bupivacaine for a successful SFICB was 0.123% (95% CI [0.098, 0.191]) and the MEC95 value was 0.188% (95% CI [0.113, 0.223]). Our study showed that the MEC90 and MEC95 values for bupivacaine administered via an SFICB for analgesia were 0.123% and 0.188%, respectively. One advantage of using lower concentrations of bupivacaine is the associated reduction in quadriceps weakness.

The 90% effective concentration of alfentanil combined with 0.075% ropivacaine for epidural labor analgesia: a single-center, prospective, double-blind sequential allocation biased-coin design.

More literature studies have reported that alfentanil is safe and effective for labor analgesia. However, there is no unified consensus on the optimal dosage of alfentanil used for epidural analgesia. This study explored the concentration at 90% of minimum effective concentration (EC90) of alfentanil combined with 0.075% ropivacaine in patients undergoing epidural labor analgesia to infer reasonable drug compatibility and provide guidance for clinical practice. In this prospective, single-center, double-blind study, a total of 45 singleton term primiparas with vaginal delivery who volunteered for epidural labor analgesia were recruited. The first maternal was administered with 3μg/mL alfentanil combined with 0.075% ropivacaine with the infusion of 10mL of the mixture every 50min at a background dose of 3mL/h. In the absence of PCEA, a total of 15mL of the mixture is injected per hour. The subsequent alfentanil concentration was determined on the block efficacy of the previous case, using an up-down sequential allocation with a bias-coin design. 30min after epidural labor analgesia, the block of patient failed with visual analog score (VAS) > 3, the alfentanil concentration was increased in a 0.5μg/mL gradient for the next patient, while the block was successful with VAS ≤ 3, the alfentanil concentration was remained or decreased in a gradient according to a randomized response list for the next patient. EC90 and 95% confidence interval were calculated by linear interpolation and prediction model with R statistical software. In this study, the estimated EC90 of alfentanil was 3.85μg/mL (95% confidence interval, 3.64-4.28μg/mL). When combined with ropivacaine 0.075%, the EC90 of alfentanil for epidural labor analgesia is 3.85μg/mL in patients undergoing labor analgesia.

Toxicity of organic solvents and surfactants to the sea urchin embryos

A comparative toxicity of widely applied organic solvents (methanol, ethanol, n-propanol, i-propanol, n-butanol, 2-butanol, i-butanol, t-butanol, 3-methoxy-3-methylbutanol-1 (MMB), ethylene glycol, diethylene glycol, 2-methoxyethanol, 2-ethoxyethanol, glycerol, ethyl acetate, acetonitrile, benzene, dioxane, dimethylformamide, dimethylacetamide, dimethylsulfoxide, 2-pyrrolidone, and N-methyl-2-pyrrolidone) and surfactants (PEG 300, PEG 6000, Tween 20, Tween 80, miramistin, and Cremophor EL) was studied using a sea urchin embryo model. Sea urchin embryo morphological alterations caused by the tested chemicals were described. The tested molecules affected P. lividus embryo development in a concentration-dependent manner. The observed phenotypic anomalies ranged from developmental delay and retardation of plutei growth to formation of aberrant blastules and gastrules, cleavage alteration/arrest, and embryo mortality. Discernible morphological defects were found after embryo exposure with common pharmaceutical ingredients, such as glycerol, Tween 80, and Cremophor EL. In general, solvents were less toxic than surfactants. PEG 6000 PEG 300, DMSO, ethanol, and methanol were identified as the most tolerable compounds with minimum effective concentration (MEC) values of 3.0–7.92 mg/mL. Previously reported MEC value of Pluronic F127 (4.0 mg/mL) fell within the same concentration range. Toxic effects of methanol, ethanol, DMSO, 2-methoxyethanol, 2-ethoxyethanol, Tween 20, and Tween 80 on P. lividus embryos correlated well with their toxicity obtained using other cell and animal models. The sea urchin embryos could be considered as an appropriate test system for toxicity assessment of solvents and surfactants for their further application as solubilizers of hydrophobic molecules in conventional in vitro cell-based assays and in vivo mammalian models. Nevertheless, to avoid adverse effect of a solubilizing agent in ecotoxicological and biological experiments, the preliminary assessment of its toxicity on a chosen test model would be beneficial.

Antifungal Susceptibility Profile of Clinical and Environmental Isolates of Aspergillus Species From a Tertiary Care Center in North India.

Aspergillus species are ubiquitously found in the environment worldwide and are important causative agents for infection. Drug resistance among Aspergillus species is emerging, hencethe present study was undertaken to look for antifungal susceptibility profiles of clinical and environmental isolates of Aspergillus species. During the period from January 2018 to June 2019, a total of 102 Aspergillus isolates (40 clinical, 40 hospital, and 22 community environment) were tested for antifungal susceptibility testing for determination of minimum inhibitory concentration (MIC)/minimum effective concentration (MEC) as per Clinical and Laboratory Standards Institute(CLSI) M38-A3 method for itraconazole, voriconazole, amphotericin B, and caspofungin. Out of these 102 Aspergillus isolates, A. flavus was the most common species present. Aspergillus species were found to have low MIC values to azoles such as itraconazole and voriconazole except for one clinical isolate, which showed a MIC value of 2 μg/ml to voriconazole. Two isolates were non-wild-type for amphotericin B, but all isolates were wild-type for caspofungin. Antifungal susceptibility testing among clinical Aspergillus isolates and environmental surveillance studies in view of emerging drug resistance should be undertaken at a larger scale.