Activation of the Calcium Receptor by Calcimimetic Agents is Preserved Despite Modest Attenuating Effects of Hyperphosphatemia

2021 ◽  
pp. ASN.2021060825
Author(s):  
William Goodman ◽  
Donald Ward ◽  
Kevin Martin ◽  
Debra Drayer ◽  
Carol Moore ◽  
...  
Keyword(s):  
Secondary Hyperparathyroidism ◽  
Receptor Activation ◽  
Serum Phosphorus ◽  
Threshold Values ◽  
Calcium Receptor ◽  
Calcimimetic Agents ◽  
Phosphorus Levels

Background Some reports indicate that serum phosphorus levels in the range seen clinically among patients undergoing dialysis attenuate calcium receptor activation and modify parathyroid hormone (PTH) release from isolated parathyroid glands in vitro. Some clinicians and providers of dialysis thus have suggested that calcimimetic agents are ineffective and should not be used to manage secondary hyperparathyroidism among those undergoing dialysis when serum phosphorus concentrations exceed certain threshold levels. Methods To determine whether hyperphosphatemia diminishes the therapeutic response to calcimimetic agents, we used data from large clinical trials to analyze the effects of etelcalcetide and cinacalcet to lower plasma PTH levels in individuals on hemodialysis who had secondary hyperparathyroidism and varying degrees of hyperphosphatemia. Results Plasma PTH levels declined progressively during 26 weeks of treatment with either etelcalcetide or cinacalcet without regard to the degree of hyperphosphatemia at baseline. However, with each calcimimetic agent, the decreases in PTH from baseline were less at each interval of follow-up during the trials among participants with serum phosphorus levels above one of three prespecified threshold values compared with those with serum phosphorus levels below these thresholds. Conclusions These in vivo findings are the first in humans to support the idea that hyperphosphatemia attenuates calcium receptor activation by calcium ions and by calcimimetic agents. The effect of hyperphosphatemia on the responsiveness to calcimimetic agents appears relatively modest, however, and unlikely to be significant therapeutically. The efficacy of treatment with calcimimetic agents for lowering plasma PTH levels among those with secondary hyperparathyroidism remains robust despite substantial elevations in serum phosphorus.

Mu-opioid receptor activation promotes in vitro and in vivo tumor growth in head and neck squamous cell carcinoma

Life Sciences ◽  
2021 ◽  
Vol 278 ◽  
pp. 119541
Author(s):  
Aysegul Gorur ◽  
Miguel Patiño ◽  
Hideaki Takahashi ◽  
German Corrales ◽  
Curtis R. Pickering ◽  
...  
Keyword(s):  
Squamous Cell Carcinoma ◽  
Tumor Growth ◽  
Cell Carcinoma ◽  
Head And Neck ◽  
Opioid Receptor ◽  
Receptor Activation ◽  
Mu Opioid Receptor ◽  
Mu Opioid

scholarly journals TRIM25 regulates oxaliplatin resistance in colorectal cancer by promoting EZH2 stability

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Sha Zhou ◽  
Jianhong Peng ◽  
Liuniu Xiao ◽  
Caixia Zhou ◽  
Yujing Fang ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Disease Free Survival ◽  
Free Survival ◽  
Epigenetic Regulator ◽  
Crc Management ◽  
Disease Free ◽  
Resistance To Chemotherapy

AbstractResistance to chemotherapy remains the major cause of treatment failure in patients with colorectal cancer (CRC). Here, we identified TRIM25 as an epigenetic regulator of oxaliplatin (OXA) resistance in CRC. The level of TRIM25 in OXA-resistant patients who experienced recurrence during the follow-up period was significantly higher than in those who had no recurrence. Patients with high expression of TRIM25 had a significantly higher recurrence rate and worse disease-free survival than those with low TRIM25 expression. Downregulation of TRIM25 dramatically inhibited, while overexpression of TRIM25 increased, CRC cell survival after OXA treatment. In addition, TRIM25 promoted the stem cell properties of CRC cells both in vitro and in vivo. Importantly, we demonstrated that TRIM25 inhibited the binding of E3 ubiquitin ligase TRAF6 to EZH2, thus stabilizing and upregulating EZH2, and promoting OXA resistance. Our study contributes to a better understanding of OXA resistance and indicates that inhibitors against TRIM25 might be an excellent strategy for CRC management in clinical practice.

Physiology, Pharmacology, and Topography of Cholinergic Neocortical Oscillations In Vitro

1997 ◽  
Vol 77 (5) ◽  
pp. 2427-2445 ◽  
Author(s):  
Heath S. Lukatch ◽  
M. Bruce Maciver
Keyword(s):  
Current Source ◽  
Brain Slices ◽  
Receptor Activation ◽  
Brain Regions ◽  
Oscillatory Activity ◽  
Cortical Layers ◽  
Eeg Activity ◽  
Layer 2

Lukatch, Heath S. and M. Bruce MacIver. Physiology, pharmacology, and topography of cholinergic neocortical oscillations in vitro. J. Neurophysiol. 77: 2427–2445, 1997. Rat neocortical brain slices generated rhythmic extracellular field [microelectroencephalogram (micro-EEG)] oscillations at theta frequencies (3–12 Hz) when exposed to pharmacological conditions that mimicked endogenous ascending cholinergic and GABAergic inputs. Use of the specific receptor agonist and antagonist carbachol and bicuculline revealed that simultaneous muscarinic receptor activation and γ-aminobutyric acid-A (GABAA)-mediated disinhibition werenecessary to elicit neocortical oscillations. Rhythmic activity was independent of GABAB receptor activation, but required intact glutamatergic transmission, evidenced by blockade or disruption of oscillations by 6-cyano-7-nitroquinoxaline-2,3-dione and (±)-2-amino-5-phosphonovaleric acid, respectively. Multisite mapping studies showed that oscillations were localized to areas 29d and 18b (Oc2MM) and parts of areas 18a and 17. Peak oscillation amplitudes occurred in layer 2/3, and phase reversals were observed in layers 1 and 5. Current source density analysis revealed large-amplitude current sinks and sources in layers 2/3 and 5, respectively. An initial shift in peak inward current density from layer 1 to layer 2/3 indicated that two processes underlie an initial depolarization followed by oscillatory activity. Laminar transections localized oscillation-generating circuitry to superficial cortical layers and sharp-spike-generating circuitry to deep cortical layers. Whole cell recordings identified three distinct cell types based on response properties during rhythmic micro-EEG activity: oscillation-on (theta-on) and -off (theta-off) neurons, and transiently depolarizing glial cells. Theta-on neurons displayed membrane potential oscillations that increased in amplitude with hyperpolarization (from −30 to −90 mV). This, taken together with a glutamate antagonist-induced depression of rhythmic micro-EEG activity, indicated that cholinergically driven neocortical oscillations require excitatory synaptic transmission. We conclude that under the appropriate pharmacological conditions, neocortical brain slices were capable of producing localized theta frequency oscillations. Experiments examining oscillation physiology, pharmacology, and topography demonstrated that neocortical brain slice oscillations share many similarities with the in vivo and in vitro theta EEG activity recorded in other brain regions.

scholarly journals Transcript and protein profiling identifies signaling, growth arrest, apoptosis, and NF-κB survival signatures following GNRH receptor activation

2012 ◽  
Vol 20 (1) ◽  
pp. 123-136 ◽  
Author(s):  
Colette Meyer ◽  
Andrew H Sims ◽  
Kevin Morgan ◽  
Beth Harrison ◽  
Morwenna Muir ◽  
...  
Keyword(s):  
Target Genes ◽  
Cultured Cells ◽  
Receptor Activation ◽  
Gnrh Receptor ◽  
Phase Changes ◽  
Protein Profiling ◽  
Proteomic Profiling ◽  
Pathway Gene

GNRH significantly inhibits proliferation of a proportion of cancer cell lines by activating GNRH receptor (GNRHR)-G protein signaling. Therefore, manipulation of GNRHR signaling may have an under-utilized role in treating certain breast and ovarian cancers. However, the precise signaling pathways necessary for the effect and the features of cellular responses remain poorly defined. We used transcriptomic and proteomic profiling approaches to characterize the effects of GNRHR activation in sensitive cells (HEK293-GNRHR, SCL60)in vitroandin vivo, compared to unresponsive HEK293. Analyses of gene expression demonstrated a dynamic response to the GNRH superagonist Triptorelin. Early and mid-phase changes (0.5–1.0 h) comprised mainly transcription factors. Later changes (8–24 h) included a GNRH target gene,CGA, and up- or downregulation of transcripts encoding signaling and cell division machinery. Pathway analysis identified altered MAPK and cell cycle pathways, consistent with occurrence of G2/M arrest and apoptosis. Nuclear factor kappa B (NF-κB) pathway gene transcripts were differentially expressed between control and Triptorelin-treated SCL60 cultures. Reverse-phase protein and phospho-proteomic array analyses profiled responses in cultured cells and SCL60 xenograftsin vivoduring Triptorelin anti-proliferation. Increased phosphorylated NF-κB (p65) occurred in SCL60in vitro, and p-NF-κB and IκBε were higher in treated xenografts than controls after 4 days Triptorelin. NF-κB inhibition enhanced the anti-proliferative effect of Triptorelin in SCL60 cultures. This study reveals details of pathways interacting with intense GNRHR signaling, identifies potential anti-proliferative target genes, and implicates the NF-κB survival pathway as a node for enhancing GNRH agonist-induced anti-proliferation.

FC 100ASSOCIATION OF SINGLE AND SERIAL MEASURES OF SERUM PHOSPHORUS WITH ADVERSE OUTCOMES IN PATIENTS ON PERITONEAL DIALYSIS: RESULTS FROM THE INTERNATIONAL PDOPPS

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Marcelo Lopes ◽  
Angelo Karaboyas ◽  
David W Johnson ◽  
Talerngsak Kanjanabuch ◽  
Martin Wilkie ◽  
...  
Keyword(s):  
Peritoneal Dialysis ◽  
Adverse Outcomes ◽  
Serum Phosphorus ◽  
Target Range ◽  
Recent Measurement ◽  
Baseline Serum ◽  
All Cause Mortality ◽  
Serial Measurements ◽  
Phosphorus Levels

Abstract Background and Aims While it has been established that high serum phosphorus is associated with mortality in hemodialysis (HD) patients, there is limited evidence in the peritoneal dialysis (PD) setting. We evaluated the association of serum phosphorus with mortality and major adverse cardiovascular events (MACE) in patients on PD, and investigated various parameterizations using single and serial measurements of serum phosphorus. Method We utilized data from 7 countries in phase 1 (2014-2017) of the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS): Australia, Canada, Japan, New Zealand, Thailand, the UK, and the US. We investigated the association of serum phosphorus and 3 outcomes: all-cause mortality, cardiovascular (CV) mortality, and MACE (CV mortality + non-fatal angina, myocardial infarction, stroke, and heart failure). We parameterized serum phosphorus using 4 different methods: (1) single measurement of baseline serum phosphorus [most recent measurement during 6-month run-in period]; (2) mean serum phosphorus over a 6-month run-in period; (3) number of months (over the past 6 months) with serum phosphorus above the target range (>4.5 mg/dL); (4) mean area-under-the-curve (AUC), calculated as the average amount of time spent with serum phosphorus >4.5 mg/dL multiplied by the extent to which this threshold was exceeded over 6 months. Cox regression was used to estimate the association between each of these 4 exposures with the time-to-event outcomes, in models thoroughly adjusted for possible confounders. Follow-up began after the 6-month run-in period and continued until the outcome occurred, 7 days after leaving the facility due to transfer or change in kidney replacement therapy modality, loss to follow-up, or end of study phase (whichever event occurred first). Results Our sample consisted of 5904 patients who were on PD. Those with higher serum phosphorus levels were younger and had lower hemoglobin levels. Compared to patients with serum phosphorus ≥3.5 to <4.5 mg/dL, we found an all-cause mortality hazard ratio (HR) of 1.62 (95% CI: 1.19, 2.20) for patients with serum phosphorus ≥ 7 mg/dL. Strong associations were also observed using serial phosphorus measures [Table]. For example, compared to the reference group of AUC=0, the HR (95% CI) of death was 1.49 (1.10, 2.00) for AUC >1 to 2; and 1.67 (1.15, 2.41) for AUC >2. Akaike Information Criteria (AIC) results showed that, among the 4 exposures, AUC was the strongest predictor of all-cause mortality, and the single phosphorus measure was the weakest predictor. Associations between serum phosphorus and adverse outcomes were generally stronger for CV death and MACE than for all-cause mortality [Table]. Conclusion As seen in HD patients, this analysis demonstrates that serum phosphorus is a strong predictor of adverse outcomes in patients on PD. When considering serial measurements of serum phosphorus, rates of adverse events began to rise at phosphorus levels >4.5 mg/dL. As recommended by KDIGO guidelines, serial measurements that consider a history of serum phosphorus excursions >4.5 mg/dL should be considered when assessing risks of adverse outcomes.

In vitro and in vivo GABAA Receptor Interaction of the Propanidid Metabolite 4-(2-[Diethylamino]-2-Oxoethoxy)-3-Methoxy-Benzeneacetic Acid

Pharmacology ◽  
2018 ◽  
Vol 103 (1-2) ◽  
pp. 10-16 ◽  
Author(s):  
Alessia Cenani ◽  
Robert J. Brosnan ◽  
Heather K. Knych
Keyword(s):  
Gabaa Receptor ◽  
Gabaa Receptors ◽  
Water Solubility ◽  
Plasma Concentrations ◽  
Receptor Activation ◽  
Receptor Interaction ◽  
Dependent Manner ◽  
Benzeneacetic Acid

Background: Propanidid is a γ-aminobutyric acid type A (GABAA) receptor agonist general anesthetic and its primary metabolite is 4-(2-[diethylamino]-2-oxoethoxy)-3-methoxy-benzeneacetic acid (DOMBA). Despite having a high water solubility at physiologic pH that might predict low-affinity GABAA receptor interactions, DOMBA is reported to have no effect on GABAA receptor currents, possibly because the DOMBA concentrations studied were simply insufficient to modulate GABAA receptors. Our objectives were to measure the propanidid and DOMBA concentration responses on ­GABAA receptors and to measure the behavioral responses of DOMBA in mice at concentrations that affect GABAA receptor currents in vitro. Methods: GABAA receptors were expressed in oocytes using clones for the human GABAA α1, β2 and γ2s subunits. The effects of DOMBA (0.2–10 mmol/L) and propanidid (0.001–1 mmol/L) on oocyte GABAA currents were studied using standard 2-electrode voltage clamp techniques. Based on in vitro results, 6 mice received ­DOMBA 32 mg intraperitoneal and were observed for occurrence of neurologic effects and DOMBA plasma concentration was measured by liquid chromatography tandem mass spectrometry. Results: DOMBA both directly activates GABAA receptors and antagonizes its GABA-mediated opening in a concentration-dependent manner at concentrations between 5–10 and 0.5–10 mmol/L respectively. In vivo, DOMBA produced rapid onset sedation at plasma concentrations that correlate with direct GABAA receptor activation. Conclusion: DOMBA modulation of GABAA receptors is associated with sedation in mice. Metabolites of propanidid analogues currently in development may similarly modulate GABAA, and impaired elimination of these metabolites could produce clinically relevant neurophysiologic effects.

scholarly journals Differential Normalization of Mucosal Interleukin-8 and Interleukin-6 Activity after Helicobacter pyloriEradication

1998 ◽  
Vol 66 (10) ◽  
pp. 4742-4747 ◽  
Author(s):  
Takafumi Ando ◽  
Kazuo Kusugami ◽  
Masahiro Ohsuga ◽  
Kenji Ina ◽  
Masataka Shinoda ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Eradication Therapy ◽  
Interleukin 8 ◽  
Biopsy Specimens ◽  
Mucosal Tissues ◽  
H Pylori ◽  
Triple Treatment

ABSTRACT There is differential resolution of mucosal infiltration with neutrophils and mononuclear cells following successfulHelicobacter pylori eradication. We investigated the effects of H. pylori eradication on mucosal interleukin-8 (IL-8) and IL-6 activity in relation to the resolution of H. pylori-associated gastritis. Eighty-one duodenal ulcer patients with H. pyloriinfection received dual- or triple-treatment eradication therapy, and mucosal biopsy specimens obtained at the initial and follow-up endoscopic examinations were cultured in vitro for 24 h. The levels of IL-8 and IL-6 were measured by enzyme-linked immunosorbent assays. In the 42 patients in whomH. pylori eradication failed, there was little change in the numbers of neutrophils and mononuclear cells infiltrating the mucosa and in IL-8 and IL-6 activity. In the 39 patients in whom H. pylori was eradicated, there was normalization both in the numbers of infiltrating neutrophils and in mucosal IL-8 activity, which was evident within 1 month following therapy. In contrast, there was a gradual resolution of mononuclear cell infiltration over a 6-month period, accompanied by a gradual normalization in IL-6 levels. Addition of H. pylori to cultures of mucosal tissues induced a significant increase in IL-8 activity in both uninfected control subjects and patients from whom H. pylori was eradicated. However, this introduction yielded a significant increase in IL-6 activity only in the latter group. This study indicates a dichotomy in the changes of mucosal IL-8 and IL-6 activity afterH. pylori eradication. The rapid normalization of IL-8 after H. pylori eradication and the ability of H. pylori cells to stimulate IL-8 in control tissues indicate that IL-8 induction is a part of the innate (nonimmune) responses to this organism. In contrast, the results of experiments analyzing IL-6 activity in cultured mucosal tissues suggest that the gradual resolution of mucosal IL-6 activity and mononuclear infiltration after successful eradication observed in vivo may reflect gradually diminishing residual immune responses against H. pylori.

Antimalaria Activity of Cassia spectabilis DC Leaf and Its Inhibition Effect in Heme Detoxification

2020 ◽  
Author(s):  
Wiwied - Ekasari ◽  
Dewi Resty Basuki ◽  
Heny - Arwati ◽  
Tutik Sri Wahy
Keyword(s):  
Antimalarial Activity ◽  
Ethanol Extract ◽  
Ic50 Value ◽  
Cassia Spectabilis ◽  
In Vivo Testing ◽  
Chloroquine Diphosphate ◽  
Better Than

Abstract Background In previous studies, Cassia spectabilis DC leaf has shown a good antimalarial activity. Therefore, this study is a follow-up study of leaf activity and mechanism of C. spectabilis DC as an antimalarial. Methods In vitro antimalarial activity testing using P. falciparum which was done with bioassay guide isolation in order to obtain the active compound. In vivo testing towards infected P. berghei mice was conducted to determine the effects of antimalarial prophylaxis and antimalarial activity in combination with artesunate. Whereas, heme detoxification inhibition testing as one of the antimalarial mechanisms was carried out using the Basilico method. Results The results showed that active antimalarial isolate obtained from C. spectabilis DC leaf had a structural pattern that was identical to (-)-7-hydroxyspectaline. Prophylactic test on infected P. berghei mice obtained the highest dose of inhibition percentage of 90% ethanol extract of C. spectabilis DC leaf was 68.61% while positive (doxycycline) control at 100 mg kg-1 was 73.54%. In antimalarial testing in combination with artesunate, it was found that administering 150 mg kg-1 (three times a day) of C. spectabilis DC (D0 − D2) + artesunate (D2) was better than the standard combination of amodiaquine + artesunate with 99.18% and 92.88% inhibition percentage. For the inhibitory activity of heme detoxification from ethanol extract 90%, C. spectabilis DC leaf had IC50 value of 0.375 mg mL-1 which was better than chloroquine diphosphate. Conclusion These results showed that C. spectabilis DC leaves possesses potent antimalarial activity and may offer a potential agent for effective and affordable antimalarial phytomedicine.

scholarly journals Model-Based Roentgen Stereophotogrammetric Analysis to Monitor the Head–Taper Junction in Total Hip Arthroplasty in Vivo—And They Do Move

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1543 ◽  
Author(s):  
Jing Xu ◽  
Robert Sonntag ◽  
J. Philippe Kretzer ◽  
Dominic Taylor ◽  
Raimund Forst ◽  
...  
Keyword(s):  
Femoral Stem ◽  
Geometrical Shape ◽  
Roentgen Stereophotogrammetric Analysis ◽  
Model Based ◽  
Similar Range ◽  
Standard Marker ◽  
Relative Migration

Model-based Roentgen stereophotogrammetric analysis (RSA) using elementary geometrical shape (EGS) models allows migration measurement of implants without the necessity of additional attached implant markers. The aims of this study were: (i) to assess the possibility of measuring potential head–taper movement in THA in vivo using model-based RSA and (ii) to prove the validity of measured head–taper migration data in vitro and in vivo. From a previous RSA study with a 10 years follow-up, retrospectively for n = 45 patients head–taper migration was calculated as the relative migration between femoral ball head and taper of the femoral stem using model-based RSA. A head–taper migration of 0.026 mm/year can be detected with available RSA technology. In vitro validation showed a total migration of 268 ± 11 µm along the taper axis in a similar range to what has been reported using the RSA method. In vivo, a proof for interchangeable applicability of model-based RSA (EGS) and standard marker-based RSA methods was indicated by a significant deviation within the migration result after 12-month follow-up for all translation measurements, which was significantly correlated to the measured head–taper migration (r from 0.40 to 0.67; p < 0.05). The results identified that model-based RSA (EGS) could be used to detect head–taper migration in vivo and the measured movement could be validated in vitro and in vivo as well. Those findings supported the possibility of applying RSA for helping evaluate the head–taper corrosion related failure (trunnionosis).

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