Bicarbonate transport along the loop of Henle effects of adrenal steroids

1995 ◽  
Vol 268 (2) ◽  
pp. F234-F239 ◽  
Author(s):  
R. Unwin ◽  
G. Capasso ◽  
G. Giebisch

The role of adrenal steroids in the regulation of bicarbonate absorption in the loop of Henle was studied by in vivo microperfusion. Bicarbonate transport (JHCO3) was measured by microcalorimetry and fluid reabsorption by [14C]inulin, 7-10 days after surgery, in 1) sham-operated control rats, 2) adrenalectomized (Adx) rats, 3) Adx rats receiving dexamethasone (1.2 micrograms.100 g body wt-1.24 h-1) and a low dose of aldosterone (0.5 micrograms.100 g body wt-1.24 h-1), 4) Adx rats receiving dexamethasone, 5) Adx rats receiving a low dose of aldosterone, and 6) Adx rats receiving a high dose of aldosterone (1.0 micrograms.100 g body wt-1.24 h-1). JHCO3 along the loop of Henle was decreased by 40% in Adx rats. JHCO3 was increased by dexamethasone alone and by dexamethasone plus a low dose of aldosterone to rates observed in fully supplemented Adx rats. Aldosterone given alone at a low physiological dose had no effect, but, when administered at a high dose, returned JHCO3 to normal.

2017 ◽  
Vol 45 (03) ◽  
pp. 557-573 ◽  
Author(s):  
Jin Wang ◽  
Ying Li ◽  
Wei-Hua Huang ◽  
Xiang-Chang Zeng ◽  
Xiao-Hui Li ◽  
...  

Abstract: Eucommia ulmoides Oliv. is a famous traditional Chinese medicine which exhibits anti-oxidative stress ability and neuro-protective effects. Aucubin is the predominant component of Eucommia ulmoides Oliv. Our present study is intended to investigate aucubin’s potential protective effects on neurons against epilepsy in the hippocampus by establishing the lithium-pilocarpine induced status epilepticus (SE) rat model in vivo. Aucubin (at a low dose and a high dose of 5[Formula: see text]mg/kg and 10[Formula: see text]mg/kg, respectively) was administered through gavage for two weeks before lithium-pilocarpine injection. Rats were sacrificed at 4, 24 and 72[Formula: see text]h after SE induction. Pretreatment with both low-dose and high-dose aucubin significantly reduced the number of death neurons ([Formula: see text]) and increased the number of surviving neurons ([Formula: see text]) in DG, Hilus, CA1 and CA3 hippocampal regions post SE. Meanwhile, it significantly inhibited necroptosis proteins (MLKL and RIP-1) ([Formula: see text] or [Formula: see text]) and enhanced autophagy protein (Beclin-1 and LC3BII/LC3BI) prevalence in the hippocampus ([Formula: see text] or [Formula: see text]). In conclusion, aucubin appeared to ameliorate damages in lithium-pilocarpine induced SE in hippocampus, reduce the number of apoptotic neurons, and increased the number of survival neurons by inducing autophagy and inhibiting necroptosis. These original findings might provide an important basis for the further investigation of the therapeutic role of aucubin in treatment or prevention of epilepsy-related neuronal damages.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Subhashis Paul ◽  
Debabrata Modak ◽  
Sutanuka Chattaraj ◽  
Deblina Nandi ◽  
Aditi Sarkar ◽  
...  

Abstract Background Aloe vera leaf gel has proven efficacious roles in the amelioration of several human diseases and illness-conditions. Specific purified gel-derived bio-constituents as well as the naturally harvested unprocessed A. vera gel have shown promise in modifying systemic inflammation. However, the synergistic role of natural herbal remedies, a mainstay of traditional Indian Ayurveda, has not been evaluated rigorously in this plant. In this study, the prevention of membrane lysis and protein denaturation in the presence of A. vera gel homogenate up to the concentration of 1000 μg/ml of gel has been assessed in vitro. Also, regulation of expression of inflammation-mediator genes (TNF-α and Cox-2) has been investigated in vivo in Freund’s complete adjuvant (FCA)-induced inflammatory arthritic Wistar albino rats in a 28-day long study following the daily oral supplementation of Aloe vera gel homogenate doses up to 0.40 and 0.80 g/kg body weight (low-dose and high-dose groups respectively). Results Our results indicated that A. vera gel homogenate inhibits hypotonicity-induced (74.89 ± 1.26%) and heat-induced (20.86 ± 0.77%) RBC membrane lyses respectively at a concentration of 1000 μg/ml, compared to indomethacin standard (80.52 ± 0.65% and 43.98 ± 1.52% respectively at 200 μg/ml concentration). The similar concentration of gel also showed 39.35 ± 4.25% inhibition of protein denaturation compared to standard diclofenac sodium (46.74 ± 1.84% at 100 μg/ml concentration) in vitro. When assessed in vivo, TNF-α expression was found to be decreased by 35.88% and 38.52%, and Cox-2 expression was found to be decreased by 31.65% and 34.96%, in low-dose and high-dose groups respectively, when compared to the arthritic controls. Conclusions Our findings justify the role of unprocessed A. vera gel homogenate in preventing tissue damage and in the downregulation of TNF-α and Cox-2 gene expressions for the immune-modulation of inflammatory arthritis condition.


2021 ◽  
Vol 19 ◽  
pp. 205873922110399
Author(s):  
Jiakui Zhang ◽  
Yong Huang

Since the discovery of interleukin-2 (IL-2) in 1979, increasing attention has been focused on its role in regulating immune function. IL-2 has been found to play an important role in maintaining autoimmune tolerance, and it is essential for the proliferation and differentiation of regulatory T cells (Treg) cells. Other studies have found that the role of IL-2 in vivo is closely related to its concentration. Low-dose IL-2 selectively stimulates the proliferation of Treg cells in vivo, while high-dose IL-2 primarily promotes the proliferation of effector T cells. In view of these findings, an increasing number of studies have focused on the use of low-dose IL-2 in the treatment of immune-related diseases in recent years. The results have been encouraging, with mild adverse reactions. This article mainly focuses on the latest progress made in the IL-2 treatment of immune-related diseases and its regulatory effect on the immune status in different diseases, providing a reference for the rational clinical application of IL-2.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Naomi S. Sta Maria ◽  
Leslie A. Khawli ◽  
Vyshnavi Pachipulusu ◽  
Sharon W. Lin ◽  
Long Zheng ◽  
...  

AbstractQuantitative in vivo monitoring of cell biodistribution offers assessment of treatment efficacy in real-time and can provide guidance for further optimization of chimeric antigen receptor (CAR) modified cell therapy. We evaluated the utility of a non-invasive, serial 89Zr-oxine PET imaging to assess optimal dosing for huLym-1-A-BB3z-CAR T-cell directed to Lym-1-positive Raji lymphoma xenograft in NOD Scid-IL2Rgammanull (NSG) mice. In vitro experiments showed no detrimental effects in cell health and function following 89Zr-oxine labeling. In vivo experiments employed simultaneous PET/MRI of Raji-bearing NSG mice on day 0 (3 h), 1, 2, and 5 after intravenous administration of low (1.87 ± 0.04 × 106 cells), middle (7.14 ± 0.45 × 106 cells), or high (16.83 ± 0.41 × 106 cells) cell dose. Biodistribution (%ID/g) in regions of interests defined over T1-weighted MRI, such as blood, bone, brain, liver, lungs, spleen, and tumor, were analyzed from PET images. Escalating doses of CAR T-cells resulted in dose-dependent %ID/g biodistributions in all regions. Middle and High dose groups showed significantly higher tumor %ID/g compared to Low dose group on day 2. Tumor-to-blood ratios showed the enhanced extravascular tumor uptake by day 2 in the Low dose group, while the Middle dose showed significant tumor accumulation starting on day 1 up to day 5. From these data obtained over time, it is apparent that intravenously administered CAR T-cells become trapped in the lung for 3–5 h and then migrate to the liver and spleen for up to 2–3 days. This surprising biodistribution data may be responsible for the inactivation of these cells before targeting solid tumors. Ex vivo biodistributions confirmed in vivo PET-derived biodistributions. According to these studies, we conclude that in vivo serial PET imaging with 89Zr-oxine labeled CAR T-cells provides real-time monitoring of biodistributions crucial for interpreting efficacy and guiding treatment in patient care.


1985 ◽  
Vol 249 (1) ◽  
pp. G137-G144 ◽  
Author(s):  
T. A. Miller ◽  
D. Li ◽  
Y. J. Kuo ◽  
K. L. Schmidt ◽  
L. L. Shanbour

By use of an in vivo canine chambered stomach preparation in which the gastric mucosa was partitioned into two equal halves, the effect of topical 16,16-dimethyl PGE2 (DMPGE2) (1 microgram/ml of perfusate) and 8% and 40% ethanol on tissue levels of nonprotein sulfhydryl compounds was assessed. Both DMPGE2 and 8% ethanol significantly increased (P less than 0.005) mucosal levels of nonprotein sulfhydryls when compared with corresponding mucosa bathed with saline alone. In contrast, mucosa bathed with 40% ethanol showed significantly decreased levels. If mucosa was bathed with DMPGE2 or 8% ethanol prior to exposing the stomach to 40% ethanol, this depletion in sulfhydryl compounds was not observed. Since other experimental observations have shown that exogenously administered prostaglandins and mild irritants (such as low-dose alcohol) can prevent gastric mucosal damage by necrotizing agents (such as high-dose alcohol), our findings are consistent with the hypothesis that nonprotein sulfhydryls may play a role in mediating gastric mucosal protection.


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A766-A766
Author(s):  
Isabelle Le Mercier ◽  
Sunny Sun ◽  
Dongmei Xiao ◽  
Laura Isacco ◽  
Daniel Treacy ◽  
...  

BackgroundT cell responses are tightly regulated and require a constant balance of signals during the different stages of their activation, expansion, and differentiation. As a result of chronic antigen exposure, T cells become exhausted in solid tumors, preventing them from controlling tumor growth.MethodsWe identified a transcriptional signature associated with T cell exhaustion in patients with melanoma and used our proprietary machine learning algorithms to predict molecules that would prevent T cell exhaustion and improve T cell function. Among the predictions, an orally available small molecule, Compound A, was highly predicted.ResultsCompound A was tested in an in vitro T cell Exhaustion assay and shown to prevent loss of proliferation and expression of immune checkpoint receptors. Transcriptionally, Compound A-treated cells looked indistinguishable from conventionally expanded, non-exhausted T cells. However, when assessed in a classical T cell activation assay, Compound A demonstrated dose dependent activity. At low dose, Compound A was immuno-stimulatory, allowing cells to divide further by preventing activation induced cell death. At higher doses, Compound A demonstrated immuno-suppressive activity preventing early CD69 upregulation and T cell proliferation. All together, these observations suggest that Compound A prevented exhaustion with a mechanism of action involving TCR signaling inhibition. While cessation of TCR signaling or rest has been recently associated with improved CAR-T efficacy by preventing or reversing exhaustion during the in vitro manufacturing phase, it is unclear if that mechanism would translate in vivo.Compound A was evaluated in the CT26 and MC38 syngeneic mouse models alongside anti-PD1. At low dose Compound A closely recapitulated anti-PD1 mediated cell behavior changes by scRNA-seq and flow cytometry in CT26 mice. At high dose, Compound A led to the accumulation of naive cells in the tumor microenvironment (TME) confirming the proposed mechanism of action. Low dose treatment was ineffective in MC38 mouse model but a pulsed treatment at high dose also recapitulated anti-PD1 activity in most animals. Importantly, we identified a new T cell population responding to anti-PD1 that was particularly increased in the MC38 mouse model; Compound A treatment also impacted this population.ConclusionsThese data confirm that mild TCR inhibition either suboptimal or fractionated can prevent exhaustion in vivo. However, this approach has a very limited window of activity between immuno-modulatory and immuno-suppressive effects, thereby limiting potential clinical benefit. Finally, these results demonstrate that our approach and platform was able to predict molecules that would prevent T cell exhaustion in vivo.


2020 ◽  
Author(s):  
Zhen-feng ZHOU ◽  
Wen Zhai ◽  
Li-na YU ◽  
Kai SUN ◽  
Li-hong SUN ◽  
...  

Abstract Background: The blood saving efficacy of TXA in cardiac surgery has been proved in several studies, but TXA dosing regimens were varied in those studies. Therefore, we performed this study to investigate if there is a dose dependent in-vivo effect of TXA on fibrinolysis parameters by measurement of fibrinolysis markers in adults undergoing cardiac surgery with CPB, which has not been systematically elucidated.Methods: A double-blind, randomized, controlled prospective trial was conducted from February 11, 2017 to May 05, 2017. Thirty patients undergoing cardiac valve surgery were identified and randomly divided into a placebo group, low-dose group and high-dose group by 1: 1: 1. Fibrinolysis parameters were measured by plasma levels of D-Dimers, plasminogen activator inhibitor-1 (PAI-1), thrombin activatable fibrinolysis inhibitor (TAFI), plasmin-antiplasmin complex (PAP), tissue plasminogen activator (tPA) and thrombomodulin (TM). Those proteins were measured at five different sample times: preoperatively before the TXA injection (T1), 5 min after the TXA bolus (T2), 5 min after the initiation of CPB (T3), 5 min before the end of CPB (T4) and 5 min after the protamine administration (T5). A Thrombelastography (TEG) and standard coagulation test were also performed.Results: Compared with the control group, the level of the D-Dimers decreased in the low-dose and high-dose groups when the patients arrived at the ICU and on the first postoperative morning. Over time, the concentrations of PAI-1, TAFI, and TM, but not PAP and tPA, showed significant differences between the three groups (p <0.05). Compared with the placebo group, the plasma concentrations of PAI-1 and TAFI decreased significantly at the T3 and T4 (p <0.05); TAFI concentrations also decreased at the T5 in low-dose group (p <0.05). Compared with the low-dose group, the concentration of TM increased significantly at the T4 in high-dose group. No significant differences were observed in the levels of the coagulation proteins at any points between the groups.Conclusions: The vivo effect of low dose TXA is equivalent to high dose TXA on fibrinolysis parameters in adults undergoing valvular cardiac surgery with cardiopulmonary bypass, and we recommend a low dose TXA regimen for those patients.Clinical trial number and registry URL: ChiCTR-IPR-17010303; http://www.chictr.org.cn, Principal investigator: Zhen-feng ZHOU, Date of registration: January 1, 2017.


2014 ◽  
Author(s):  
Δημήτριος Λυσίτσας

Εισαγωγή: Η υπερπλασία του έσω χιτώνα παίζει μείζων ρόλο στην επαναστένωση (in-stentrestenosis). Στην παρούσα μελέτη αξιολογήσαμε in vitro την επίδραση της D-24851(κυτταροτοξική ουσία που σταματά τον κυτταρικό κύκλο στο στάδιο G2-M) στονπολλαπλασιασμό των λείων μυϊκών κυττάρων και μελετήσαμε την ασφάλεια και τηνδραστικότητα μίας ενδαγγειακής πρόθεσης (stent) επικαλυμμένης με πολυμερή ουσία πουαπελευθερώνει την D-24851, στην αναστολή της υπερπλασίας του έσω χιτώνα χωρίς ναεμποδίζει την αναγεννητική ικανότητα του ενδοθηλίου σε in vivo πειραματικό μοντέλο.Υλικό και Μέθοδοι: Γυμνά μεταλλικά stent (n=6), stent επικαλυμμένα μόνο με πολυμερήουσία (polymer-coated, n=7) και stent επικαλυμμένα με πολυμερή ουσία πουαπελευθερώνουν 31±1μg (low-dose, n=7), 216±8 μg (high-dose, n=6) ή 1774±39 μg(extreme-dose, n=5) της D-24851 εμφυτεύτηκαν στις μηριαίες αρτηρίες λευκών New Zealandκουνελιών. Τα πειραματόζωα θυσιάστηκαν στις 28 ημέρες για ιστομορφομετρική ανάλυση.Για την αξιολόγηση της ενδοθηλιακής αναγέννησης στις 90 ημέρες, 12 πειραματόζωαχρησιμοποιήθηκαν για την τοποθέτηση polymer-coated (n=3), low dose (n=3), high dose(n=3) or extreme dose (n=3) ενδαγγειακών προθέσεων.Αποτελέσματα: In vitro η D-24851 αναστέλλει την υπερπλασία των λείων μυϊκών κυττάρωνκαι επάγει την απόπτωση τους χωρίς να αυξάνει την επαγωγή της heat shock protein 70(HSP-70), μία κυτταροπροστατευτική και αντι-αποπτωτική πρωτεΐνη. Η θεραπεία με lowdoseD-24851 stents συνδυάστηκε με 38% (P=0.029) μείωση της υπερπλαστικής περιοχήςτου έσω χιτώνα και 35% (P=0.003) μείωση της επι τοις εκατό στένωσης του αυλού σεσύγκριση με τα γυμνά μεταλλικά stents. Ο τραυματισμός και η φλεγμονή του αρτηριακού τοιχώματος δεν παρουσίασαν σημαντικές διαφορές μεταξύ των ομάδων. Τα επικαλυμμέναμόνο με πολυμερή ουσία stents εμφάνισαν παρόμοια ανάπτυξη νεοιστού σε σύγκριση με ταγυμνά μεταλλικά stents. Ωστόσο, όλες οι ομάδες των stents με D-24851 παρουσίασαν ατελήενδοθηλιοποίηση συγκρινόμενα με τα polymer-coated stents.Συμπεράσματα: Οι επικεκαλυμμένες ενδαγγειακές προσθέσεις με πολυμερή ουσία καιχαμηλη δόση D-24851 μειώνουν σημαντικά την υπερπλασιά του έσω χιτώνα. Λόγω τηςατελούς ενδοθηλιοποίησης, μακράς διάρκειας μελέτες είναι απαραίτητες για ναπιστοποιήσουν ότι η αναστολή του νεοιστού παραμένει και μετά τις 28 ημέρες.


Author(s):  
N Singh ◽  
Sh Ahamed ◽  
A Sinha ◽  
Sh Srivastava ◽  
N K Painuly ◽  
...  

Background: Intracavitary brachytherapy plays a major role in management of cervical carcinoma. Assessment of dose received by OAR’s therefore becomes crucial for the estimation of radiation toxicities in high dose rate brachytherapy.Objective: The purpose of this study is to evaluate the role of in vivo dosimetry in HDR brachytherapy and to compare the actual doses delivered to OAR’s with those calculated during treatment planning.Materials and Methods: A total of 50 patients were treated with Microselectron HDR. Out of 50 patients, 26 were treated with a dose of 7 Gy and 24 with a dose of 9 Gy, prescribed to point A. Brachytherapy planning and evaluation of dose to the bladder and rectum was done on TPS & in vivo dosimetry was performed using portable MOSFET.Results: The calibration factors calculated for both the dosimeters are almost equal and are 0.984 cGy/mV and 1.0895 cGy/mV. For bladder, dose deviation was found to be within +/- 5% in 28 patients, +/- 5-10% in 14 patients, +/- 10-15% in 4 patients. The deviation between the TPS-calculated dose and the dose measured by MOSFET for rectum was within +/- 5% in 31 patients, +/- 5–10% in 8 patients, and +/- 10–15% in 7 patients.Conclusion: TPS calculated doses were slightly higher than that measured by MOSFET. The use of a small size of MOSFET dosimeter is an efficient method for accurately measuring doses in high-dose gradient fields typically seen in brachytherapy. Therefore, to reduce risk of large errors in the dose delivery, in vivo dosimetry can be done in addition to TPS computations.


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