Phthalate and DINCH exposure and ovarian reserve markers among women seeking infertility care

Phthalate exposure can adversely impact ovarian reserve, yet investigation on the influence of its alternative substance, the non-phthalate plasticizer diisononyl-cyclohexane-1,2-dicarboxylate (DINCH), on ovarian reserve is very sparce. We aimed to investigate the associations of phthalate and DINCH exposure as well as their combined mixture with ovarian reserve. This present study included 657 women seeking infertility care in Jiangsu, China (2015-2018). Urine samples during enrollment prior to infertility treatment were analyzed using high-performance liquid chromatography-isotope dilution tandem mass spectrometry (UPLC-MS/MS) to quantify 17 phthalate metabolites and 3 DINCH metabolites. Multivariate linear regression models, Poisson regression models and weighted quantile sum (WQS) regression were performed to access the associations of 17 urinary phthalate metabolites and 3 DINCH metabolites with ovarian reserve markers, including antral follicle count (AFC), anti-Mullerian hormone (AMH), and follicle-stimulating hormone (FSH). We found that the most conventional phthalates metabolites (DMP, DnBP, DiBP, DBP and DEHP) were inversely associated with AFC, and the DINCH metabolites were positively associated with serum FSH levels. The WQS index of phthalate and DINCH mixtures was inversely associated with AFC (% change = -8.56, 95 % CI: -12.63, -4.31) and positively associated with FSH levels (% change =7.71, 95 % CI: 0.21, 15.78). Our findings suggest that exposure to environmental levels of phthalate and DINCH mixtures is inversely associated with ovarian reserve.

The shikimate pathway: gateway to metabolic diversity

Covering: 1997 to 2023The shikimate pathway is the metabolic process responsible for the biosynthesis of the aromatic amino acids phenylalanine, tyrosine, and tryptophan. Seven metabolic steps convert phosphoenolpyruvate (PEP) and erythrose 4-phosphate (E4P) into shikimate and ultimately chorismate, which serves as the branch point for dedicated aromatic amino acid biosynthesis. Bacteria, fungi, algae, and plants (yet not animals) biosynthesize chorismate and exploit its intermediates in their specialized metabolism. This review highlights the metabolic diversity derived from intermediates of the shikimate pathway along the seven steps from PEP and E4P to chorismate, as well as additional sections on compounds derived from prephenate, anthranilate and the synonymous aminoshikimate pathway. We discuss the genomic basis and biochemical support leading to shikimate-derived antibiotics, lipids, pigments, cofactors, and other metabolites across the tree of life.

An organic O donor for biological hydroxylation reactions

All biological hydroxylation reactions are thought to derive the oxygen atom from one of three inorganic oxygen donors, O2, H2O2, or H2O. Here, we have identified the organic compound prephenate as the oxygen donor for the three hydroxylation steps of the O2-independent biosynthetic pathway of ubiquinone, a widely distributed lipid coenzyme. Prephenate is an intermediate in the aromatic amino acid pathway and genetic experiments showed that it is essential for ubiquinone biosynthesis in Escherichia coli under anaerobic conditions. Metabolic labeling experiments with 18O-shikimate, a precursor of prephenate, demonstrated the incorporation of 18O atoms into ubiquinone. The role of specific iron-sulfur enzymes belonging to the widespread U32 protein family is discussed. Prephenate-dependent hydroxylation reactions represent a unique biochemical strategy for adaptation to anaerobic environments.

Metabotropic Glutamate Receptor 4 (mGlu4) Positive Allosteric Modulators Lack Efficacy in Rat and Marmoset Models of L-DOPA-Induced Dyskinesia

Background

Increased activity across corticostriatal glutamatergic synapses may contribute to L-DOPA-induced dyskinesia in Parkinson's disease. Given the weak efficacy and side-effect profile of amantadine, alternative strategies to reduce glutamate transmission are being investigated. Metabotropic glutamate receptor 4 (mGlu4) is a promising target since its activation would reduce glutamate release.

Objective

We hypothesized that two mGlu4 positive allosteric modulators, Lu AF21934 ((1 S,2 R)-N1-(3,4-dichlorophenyl)cyclohexane-1,2-dicarboxamide) and ADX88178 (5-Methyl-N-(4-methylpyrimidin-2-yl)-4-(1H-pyrazol-4-yl)thiazol-2-amine), would provide relief in rat and primate models of L-DOPA-induced dyskinesia.

Methods

The ability of Lu AF21934 or ADX88178 to reverse pre-established dyskinesia was examined in L-DOPA-primed 6-hydroxydopamine-lesioned rats expressing abnormal involuntary movements (AIMs) or in 1-methyl-4-phenyl,1,2,3,6-tetrahydropyridine (MPTP)-treated common marmosets expressing L-DOPA-induced dyskinesia. Additionally, the ability of Lu AF21934 to prevent the development of de novo L-DOPA-induced AIMs was explored in the 6-hydroxydopamine-lesioned rats.

Results

Neither Lu AF21934 (10 or 30 mg/kg p.o.) nor ADX88178 (10 or 30 mg/kg p.o.) reduced pre-established AIMs in 6-hydroxydopamine-lesioned rats. Similarly, in L-DOPA-primed common marmosets, no reduction in established dyskinesia was observed with Lu AF21934 (3 or 10 mg/kg p.o.). Conversely, amantadine significantly reduced (>40%) the expression of dyskinesia in both models. Lu AF21934 also failed to suppress the development of AIMs in 6-hydroxydopamine-lesioned rats.

Conclusions

This study found no benefit of mGlu4 positive allosteric modulators in tackling L-DOPA-induced dyskinesia. These findings are concordant with the recent failure of foliglurax in phase II clinical trials supporting the predictive validity of these pre-clinical dyskinesia models, while raising further doubt on the anti-dyskinetic potential of mGlu4 positive allosteric modulators.

Natural Oil Lure Outperforms Trimedlure in Capturing Males of the Mediterranean Fruit Fly, Ceratitis capitata (Diptera: Tephritidae)

Females of certain tephritid fruit fly species (Diptera: Tephritidae) pose an enormous agricultural threat, as they oviposit in commercially important fruits and vegetables. Trapping networks are often operated in fruit fly-free areas to detect incipient infestations. Trapping relies largely on male attractants, so-called male lures, with trimedlure (TML) being used to detect invasive Ceratitis spp. Operating large-scale surveillance programs incurs substantial costs for both supplies and labor, and the problem is exacerbated by the fact that trimedlure (as well as other male lures) is effective for relatively short intervals in the field (6-8 weeks). Because frequent servicing increases costs, there is considerable interest in modifying existing lures or developing new formulations to extend their effective field longevity. Here, we present results of a field study in Hawaii on a wild population of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), that compared male captures in traps baited with (i) fresh liquid TML, (ii) TML plugs, (iii) a novel controlled-release TML sachet, and (iv) a novel natural oil blend dispensed from a sachet. Catch was recorded weekly for 12 weeks and then at 16 and 20 weeks, with 12 traps deployed per treatment. The natural oil formulation, which contains the natural plant product α-copaene, was as effective as the fresh liquid TML even after weathering for 20 weeks. Future work will focus on developing a dispenser for this formulation that is compatible with standard trap design and deployment.

Molecular recognition of niacin and lipid-lowering drugs by the human hydroxycarboxylic acid receptor 2

Niacin, an age-old lipid-lowering drug, acts through the hydroxycarboxylic acid receptor 2 (HCAR2), a G-protein-coupled receptor (GPCR). Yet, its use is hindered by side effects like skin flushing. To address this, specific HCAR2 agonists, like MK-6892 and GSK256073, with fewer adverse effects have been created. However, the activation mechanism of HCAR2 by niacin and these new agonists is not well understood. Here, we present three cryoelectron microscopy structures of Gi-coupled HCAR2 bound to niacin, MK-6892, and GSK256073. Our findings show that different ligands induce varying binding pockets in HCAR2, influenced by aromatic amino acid clusters (W91ECL1, H1614.59, W1885.38, H1895.39, and F1935.43) from receptors ECL1, TM4, and TM5. Additionally, conserved residues R1113.36 and Y2847.43, unique to the HCA receptor family, likely initiate activation signal propagation in HCAR2. This study provides insights into ligand recognition, receptor activation, and G protein coupling mediated by HCAR2, laying the groundwork for developing HCAR2-targeted drugs.

β-Peptides incorporating polyhydroxylated cyclohexane β-amino acid: synthesis and conformational study

We describe the synthesis of trihydroxylated cyclohexane β-amino acids from (-)-shikimic acid, in their cis and trans configuration, and the incorporation of the trans isomer into a trans-2-aminocyclohexanecarboxylic acid peptide chain. Subsequently, the hydroxyl groups were partially or totally deprotected. The structural study of the new peptides by FTIR, CD, solution NMR and DFT calculations revealed that they all fold into a 14-helix secondary structure, similarly to the homooligomer of trans-2-aminocyclohexanecarboxylic acid. This means that the high degree of substitution of the cyclohexane ring of the new residue is compatible with the adoption of a stable helical secondary structure and opens opportunities for the design of more elaborate peptidic foldamers with oriented polar substituents at selected positions of the cycloalkane residues.

Comparative Descriptive Analysis of Physician Versus Patient-Directed Gabapentin Usage In Chronic Pain - A Preliminary Report

BACKGROUND

Gabapentin is one of the most common medications employed in Pain Medicine, specifically targeting the management of neuropathic pain. We are most familiar with the incremental dosing strategy where a ceiling dose is eventually attained guided by efficacy and patient tolerance, after which a fixed dosing regimen is prescribed. We propose that autonomous short-term dose variations per patient could have rapid clinically significant effects in the management of chronic pain.

OBJECTIVES

This study examines the frequency at which patients take gabapentin on a fixed vs variable schedule and how the pattern of gabapentin use correlates with efficacy, side effects, and patient satisfaction.

STUDY DESIGN

Single institution, cross-sectional observational survey study with data collection performed over 2 phases as a pilot for proof of concept.

SETTING

Remote contact via telephone with researchers calling from a quiet, private location within the hospital complex conducive for confidential conversation.

METHODS

Patients recently prescribed gabapentin were queried on the patterns of use and self-perceived efficacy, satisfaction, and side effects in accordance to a standardized oral script. Patients selected met the criteria of being new patients freshly prescribed gabapentin who have been consistently on the medication for at least a month, while having chronic pain symptoms for over 3 months. Responses were collected in the form of a 5-point Likert scale. Statistical analyses were performed using GraphPad Prism.

RESULTS

Of the 222 patients, 92 patients agreed to participate in the survey for a response rate of 41.4. Of these, 51% had terminated the medication for various reasons. Of the patients still taking gabapentin, 73% were on a fixed schedule, while 27% were on a variable dosing schedule. Variable dosing cohort reported better efficacy (P = 0.027) and satisfaction (P = 0.036), while the side-effect profile between the 2 groups was similar.

LIMITATIONS

The study is limited by its nature of being a pilot, single-institution study performed on a relatively small sample size. None of the patients we surveyed had been given the autonomy to adjust gabapentin doses by their providers and this could significantly reduce the proportion of patients who would be encouraged to run a variable dosing regimen.

CONCLUSIONS

This pilot study suggests that a significant portion of patients choose to administer variable doses of gabapentin and associate this with better efficacy and satisfaction. A larger study is needed to confirm this supposition. Based upon this pilot study, the variable dosing option may be an option for improved therapeutic efficacy or as an alternative to those whose lifestyles do not allow for fixed dosing regimens. Discussion of the risks of gabapentin, including respiratory depression, and clear dosage parameters of use, would need to be outlined when considering a variable dose regimen.

Orthosteric ligand selectivity and allosteric probe dependence at Hydroxycarboxylic acid receptor HCAR2

Hydroxycarboxylic acid receptor 2 (HCAR2), a member of Class A G-protein-coupled receptor (GPCR) family, plays a pivotal role in anti-lipolytic and anti-inflammatory effects, establishing it as a significant therapeutic target for treating dyslipidemia and inflammatory diseases. However, the mechanism underlying the signaling of HCAR2 induced by various types of ligands remains elusive. In this study, we elucidate the cryo-electron microscopy (cryo-EM) structure of Gi-coupled HCAR2 in complex with a selective agonist, MK-6892, resolved to a resolution of 2.60 Å. Our structural analysis reveals that MK-6892 occupies not only the orthosteric binding pocket (OBP) but also an extended binding pocket (EBP) within HCAR2. Pharmacological assays conducted in this study demonstrate that the OBP is a critical determinant for ligand selectivity among the HCARs subfamily. Moreover, we investigate the pharmacological properties of the allosteric modulator compound 9n, revealing its probe-dependent behavior on HCAR2 in response to varying orthosteric agonists. Collectively, our findings provide invaluable structural insights that contribute to a deeper understanding of the regulatory mechanisms governing HCAR2 signaling transduction mediated by both orthosteric and allosteric ligands.

Elsholblanosides A-D, Four New Oleuropeic Acid Derivatives Isolated from Elsholtzia blanda and Their Inhibition of NO Production in LPS-activated RAW264.7 Cells

Phytochemical investigation on the aerial parts of Elsholtzia blanda Benth. afforded four new oleuropeic acid derivatives (1-4), named as elsholblanosides A-D, respectively, together with 11 known compounds (5-15). Their structures were determined based on extensive analyses of HR-ESI-MS, 1D and 2D NMR, and ECD spectra. Compounds 1-4 and 14 showed moderate NO production inhibition in LPS-activated RAW264.7 cells with their IC50 values ranging from 23.2 to 86.33 μM, compared to that of the positive control compound, dexamethasone, IC50 value of 16.9 μM.

Cyclohexanecarboxylic acid degradation with simultaneous nitrate removal by Marinobacter sp. SJ18

Naphthenic acid (NA) is a toxic pollutant with potential threat to human health. However, NA transformations in marine environments are still unclear. In this study, the characteristics and pathways of cyclohexanecarboxylic acid (CHCA) biodegradation were explored in the presence of nitrate. The results showed that CHCA was completely degraded with pseudo-first-order kinetic reaction under aerobic and anaerobic conditions, accompanied by nitrate removal rates exceeding 70%, which was positively correlated with CHCA degradation (P < 0.05). In the proposed CHCA degradation pathways, cyclohexane is dehydrogenated to form cyclohexene, followed by ring-opening by dioxygenase to generate fatty acid under aerobic conditions or cleavage of cyclohexene through β-oxidation under anaerobic conditions. Whole genome analysis indicated that nitrate was removed via assimilation and dissimilation pathways under aerobic conditions and via denitrification pathway under anaerobic conditions. These results provide a basis for alleviating combined pollution of NA and nitrate in marine environments with frequent anthropogenic activities.

Apoptosis is responsible for the cytotoxic effects of anti-GD2 ganglioside antibodies and aurora A kinase inhibitors on human neuroblastoma cells

In recent years, immunotherapy has been identified as an effective treatment method for high-risk neuroblastoma. A previous study demonstrated that an anti-GD2 ganglioside (GD2) mouse 14G2a monoclonal antibody (mAb) combined with a small molecule, i.e., an aurora A kinase inhibitor (MK-5108), significantly increased cytotoxicity against human neuroblastoma cells, as compared to monotherapy. This study aimed to demonstrate the mechanism of neuroblastoma cell death in vitro following the addition of an anti-GD2 human-mouse chimeric ch14.18/CHO mAb (presently used in clinics) and two aurora A inhibitors (MK-5108 and MK-8745). The effects of the aforementioned agents on neuroblastoma cells were determined by measuring the level of ATP, the level of apoptotic and necroptotic markers, and the activity of caspase 3/7. The results revealed that the ch14.18/CHO mAb decreased cellular ATP levels in the IMR-32 and CHP-134 neuroblastoma cell lines, similarly to the 14G2a mAb. Regarding ch14.18/CHO mAb treated IMR-32 cells, the observed cytotoxic effect was concomitant with induced caspase 3 cleavage, which indicated the induction of apoptosis in IMR-32 cells, but not in CHP-134 cells. Furthermore, the MK-5108 inhibitor induced apoptosis, as indicated by the increased cleavage of caspase 3 and increased activity of caspase 3/7. However, the presence of necroptosis was ruled out in MK-5108-treated IMR-32 and CHP-134 cells. In summary, the effects of the combination of ch14.18/CHO mAb and aurora A kinase inhibitors (MK-5108 and MK-8745) were shown to enhance apoptosis in IMR-32 cells compared to when used individually.

The novel piperazino-enaminone JOAB-40 reduced colitis severity in mice via inhibition tumor necrosis factor-α and interleukin-1β

BRIEF INTRODUCTION

The synthetic compound enaminone E121 has an established role as a potent anti-tussive, bronchodilator and anti-inflammatory agent in asthma, cough, and colitis induced animal models. The addition of an N-alkylated piperazine motif to the terminal end of E121 lead to the generation of various analogues such as JOAB-40. JOAB-40 was shown to be more potent than the lead compound E121 in inhibiting the expression of the chemokine receptor CCR2, ERK1/2 phosphorylation, and the release of pro-inflammatory cytokines in vitro.

MAIN OBJECTIVE OF THE STUDY

We hypothesize that JOAB-40 is more potent than the lead compound E121 in reducing colitis severity in mice in part through inhibiting the release of TNFα and IL-1β.

METHODS

Colitis was induced by dextran sulfate sodium (DSS) administration using prophylactic and treatment approaches. The severity of the inflammation was determined by the gross (macroscopic) and histological (microscopic) assessments. The levels of TNFα, IL-1β, and IL-10 release in response to lipopolysaccharide (LPS) stimulation from the adherent murine macrophage cell line J774.2 in vitro, and the circulating levels of TNFα in vivo was measured by ELISA-based technique.

SIGNIFICANT FINDINGS FROM THE STUDY

E121 administration (1-60 mg/kg) in mice with established colitis (treatment approach) did not reduce colitis severity. On the other hand, JOAB-40 administration significantly reduced colitis severity in mice when administered using two approaches; a) prophylactic (given along colitis induction), and b) treatment (given after colitis was established) with doses as low as 10 mg/kg. The degree of inhibition of TNFα and IL-1β (but not IL-10) release from J774.2 cell line in response to LPS stimulation was more potent with JOAB-40 than E121. This was also observed in vivo in regards to the circulating levels of TNFα.

RELEVANT CONTRIBUTION TO KNOWLEDGE

Our results indicate that JOAB-40 is more potent than E121 in reducing colitis severity in mice and may be a promising future therapeutic target for the management of inflammatory bowel disease (IBD).

Improving the Lifetime Efficiency of Trimedlure-Dispensing System in Trapping the Fruit Fly Ceratitis capitata Using Polyethylene Matrix

Detection of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), is highly reliant on traps loaded with trimedlure (TML), a male-specific attractant. The successful application of attractants requires that constituents are placed in a suitable dispensing system to reduce volatilization and increase the effective field longevity of the attractant. A series of trials were conducted in different fruit orchards to test 1) the efficiency of a polyethylene-matrix plug in regulating the emission rate of TML 2) and the lifetime attractiveness of the plug compared to the cotton wick dispenser. Cotton dispensers containing the recommended dose of TML (0.75 cm3) and with a double dose (1.5 cm3) remained active for 6 and 8 wk, respectively. The increase in TML dose from 0.75 cm3 to 1.5 cm3 led to an increase in the longevity of the cotton dispenser, but there was no significant difference between the doses in biological activity. In all trials, TML-polyethylene matrix dispensers were more efficient under field conditions as they attracted more males for up to 12 wk and prolonged the release of TML more than the cotton wick dispensers. The TML-loaded polyethylene matrix dispensers might be useful in 1) minimizing the losses of the liquid TML from cotton wicks, 2) avoiding the damage that occurs when using other dispensers, 3) prolonging the TML lifetime in the field through regulating its release rates, 4) potentially minimizing the adverse effect of high temperatures on release rate, and, finally, 5) minimizing the costs of using large amounts of expensive TML solutions.

Gabapentin: Change is in the Wind

In the midst of a national opioid crisis, Americans have a heightened awareness of the potential for prescription drugs that can be abused. One drug-gabapentin-is frequently prescribed in long-term care facilities for seizures and postherpetic neuralgia, and its use is a growing concern globally. Approved for two uses, but used off-label for many others, gabapentin can induce euphoria at high doses. In older adults, clinicians prescribe it for seizures, pain, migraine, and aggression associated with dementia, among other things. Gabapentin's rapid onset of action, side effect profile, limited drug-drug interactions, and extensive pharmacokinetic data in renal impairment have made prescribers comfortable using it in older adults. This gabapentinoid-a cousin to the Schedule V drug pregabalin-has seen widespread recreational abuse and has led to its reclassification in the United Kingdom and in several U.S. states. Consultant pharmacists need to be aware that the evidence behind off-label use is scant; withdrawal is likely after as few as three weeks of treatment; and drug diversion is possible, even likely. In addition, it is the tenth-most prescribed medication in the United States.

A Meta-Analysis of Therapeutic Efficacy and Safety of Gabapentin in the Treatment of Postherpetic Neuralgia from Randomized Controlled Trials

OBJECTIVE

The study aims to systematically evaluate the clinical effect of gabapentin in the treatment of postherpetic neuralgia (PHN).

METHOD

Data were retrieved electronically from PubMed, Embase, CNKI, the China Biomedical Database, and the Library of Clinical Database, beginning from the time of inception to April 2017, in order to collect data on randomized controlled trials (RCTs) of gabapentin and placebo in PHN treatment.

RESULTS

A total of 11 RCTs (2376 people) were retrieved. The gabapentin group reported significantly reduced pain intensity [MD=-0.91, 95% CI -1.32 to -0.51, P<0.00001] compared with the placebo group. Those treated with gabapentin also experienced significantly improved sleep quality [SMD=-0.44, 95% CI -0.66 to -0.23, P<0.0001], but were more likely to experience incidence of adverse events, such as somnolence, dizziness, and peripheral edema. Results of the subgroup analysis showed that the source of heterogeneity may be related to the formulations of the drug.

CONCLUSION

Gabapentin can be used to effectively and safely treat PHN.

Suppression of Mediterranean Fruit Fly (Diptera: Tephritidae) With Trimedlure and Biolure Dispensers in Coffea arabica (Gentianales: Rubiaceae) in Hawaii

To assess the potential to suppress Mediterranean fruit fly, Ceratitis capitata (Wiedemann; Diptera: Tephritidae), via mass trapping with Trimedlure (TML), we compared fly catch (as catch per trap per time period) provided by either a novel, solid, triple-lure dispenser with TML, methyl eugenol (ME), and raspberry ketone (RK) (TMR) or solid TML plugs, both without insecticides, in addition to Biolure bait stations. Work was done in a coffee plantation that had a dense C. capitata population. Three treatments were compared: 1) TMR or TML (50 traps per ha), 2) Biolure (50 traps per ha), 3) TML (25 per ha) or TMR (25 per ha) + Biolure (25 per ha), and 4) an untreated control. During coffee season, based on C. capitata captures (mean flies per trap per wk) inside plastic McPhail traps, all treatments were significantly different than the control: Biolure (9.57) = TMR (11.28) = Biolure +TMR (13.50) < Control (36.06 flies/trap/wk). During non-coffee season, all treatments were significantly different than the control and TML was significantly lower than Biolure (wax matrix bait stations): TML (0.95) < Biolure (1.43) = Biolure +TML (1.77) < Control (2.81 flies/trap/wk). Surprisingly, captures were not lower in plots treated with combinations of Biolure + TMR or TML, compared to individual plots with Biolure or TML or TMR alone. Mass trapping with either TML or TMR dispensers deserves further study as a component of Integrated Pest Management programs for C. capitata in Hawaii and may have global potential for management of C. capitata.