Effects of indomethacin on brain blood flow and cerebral metabolism in hypoxic newborn piglets

1993 ◽  
Vol 264 (1) ◽  
pp. H141-H149 ◽  
Author(s):  
M. G. Coyle ◽  
W. Oh ◽  
B. S. Stonestreet
Keyword(s):  
Blood Flow ◽  
Glucose Metabolism ◽  
Dose Group ◽  
Low Dose ◽  
Severe Hypoxia ◽  
High Dose Group ◽  
High Dose ◽  
Brain Blood Flow ◽  
Newborn Piglets ◽  
Dose Dependent

We tested the hypotheses that in newborn piglets indomethacin (Indo) pretreatment blunts the hyperemic brain blood flow (BF) and alters the cerebral metabolic responses to hypoxia and that these responses are dose dependent. We studied 23 chronically instrumented piglets exposed to graded hypoxia (O2 content: 7.1-0.4 microM O2/ml) after pretreatment with high (5 mg/kg, n = 8)-or low (0.3 mg/kg, n = 6)-dose Indo or placebo (diluent, n = 9). Total and regional brain BF increased significantly with decreasing O2 content values (P < 0.01) in all three groups. However, the rise in the brain BF curves with decreasing O2 content values was significantly (P < 0.05) lower in the high-compared with the low-dose group in all brain regions with the greatest effect in the caudal regions. Furthermore, the BF curves in the placebo-treated animals were similar to the low-dose group. The cerebral metabolic rate of O2 (CMR(O2)) and glucose metabolism were preserved in the three groups over all hypoxic ranges until severe hypoxia (O2 content < or = 1.1 microM O2/ml) was achieved in the high-dose group, when CMR(O2) decreased (P < 0.05), and glucose metabolism increased (P < 0.05). The mean arterial blood pressure in the high-dose group during severe hypoxia was 45 mmHg (P > 0.05). Although coupling of cerebral BF and CMR(O2) was preserved in the three groups, this association was significantly altered with high-dose pretreatment. We conclude that an attenuation in the hypoxia-induced brain perfusion by Indo is dose dependent. Alterations in CMR(O2) and glucose metabolism are observed with high-dose pretreatment during severe hypoxia, and the responses to hypoxia are similar with placebo and low-dose Indo pretreatment.

Effects of indomethacin on brain blood flow, cerebral metabolism, and sagittal sinus prostanoids after hypoxia

1995 ◽  
Vol 269 (4) ◽  
pp. H1450-H1459 ◽  
Author(s):  
M. G. Coyle ◽  
W. Oh ◽  
K. H. Petersson ◽  
B. S. Stonestreet
Keyword(s):  
Blood Flow ◽  
Low Dose ◽  
Cerebral Metabolism ◽  
Brain Regions ◽  
Cerebral Hypoperfusion ◽  
High Dose ◽  
Brain Blood Flow ◽  
Newborn Piglets ◽  
Sagittal Sinus ◽  
Dose Dependent

We tested the hypotheses that during recovery from hypoxia, newborn piglets exhibit a posthypoxic cerebral hyperemia, indomethacin-pretreated piglets exhibit a posthypoxic cerebral hypoperfusion, and that the changes caused by indomethacin are dose dependent and related to the loss of prostanoids. We studied piglets exposed to 40 min of hypoxia after pretreatment with high (5 mg/kg, n = 9) or low (0.3 mg/kg, n = 8) doses of indomethacin or placebo (n = 9) and allowed to recover for 120 min. In the placebo and low-dose pretreatment groups, total and regional brain blood flow increased during hypoxia but returned to baseline 10 min after hypoxia. High-dose indomethacin pretreatment was associated with a posthypoxic hypoperfusion to certain brain regions at 10 min of recovery to values similar to those after indomethacin treatment before the onset of hypoxia. During and after hypoxia, the cerebral metabolic rate of oxygen was preserved in both the placebo and low-dose groups and decreased significantly during hypoxia in the high-dose group. Sagittal sinus prostacyclin was reduced significantly in both indomethacin-treated groups throughout the study. We conclude that a posthypoxic hyperemia is not observed in newborn piglets. This finding was not altered by pretreatment with a therapeutic dose of indomethacin, whereas a pharmacological dose was associated with selective hypoperfusion to certain brain regions both before hypoxia and during recovery from hypoxia.

Failure of oxygen radical scavengers to modify fatigue in electrically stimulated muscle

1991 ◽  
Vol 69 (10) ◽  
pp. 1470-1475 ◽  
Author(s):  
Ian Shrier ◽  
Sabah Hussain ◽  
Sheldon Magder
Keyword(s):  
Blood Flow ◽  
Dose Group ◽  
Gastrocnemius Muscle ◽  
Low Dose ◽  
Muscle Tension ◽  
Oxygen Radical ◽  
High Dose Group ◽  
High Dose ◽  
Partial Recovery ◽  
Radical Scavengers

We used in situ gastrocnemius muscle of anaesthetized dogs to test the hypothesis that O2 radical production during muscle contraction contributes to fatigue. Muscle tension was measured with a force transducer and blood flow was monitored with an electromagnetic flow probe. Muscle contractions were produced by stimulating the nerve for 15 min at 20 Hz, 12 trains/min, and a duty cycle of 0.25. Three groups of seven animals were given an infusion of 0.2 mL∙min−1 of either saline, low-dose oxygen radical scavengers (250 IU∙mL−1 superoxide dismutase, 640 IU∙mL−1 polyethylene glycol (PEG)-catalase, 0.25 mg∙mL−1 deferoxamine, and 0.1 mg∙mL−1 oxypurinol), or high-dose oxygen radical scavengers (3300 IU∙mL−1 uperoxide dismutase, 6600 IU∙mL−1 PEG-catalase, 2.5 mg∙mL−1 deferoxamine, and 0.1 mg∙mL−1 oxypurinol). Blood flow and vascular resistance of the gastrocnemius muscle during stimulation did not differ among groups. After 15 min of stimulation, the developed tension (represented as a percentage of initial tension developed) was 66 ± 7% in the saline treated group, 70 ± 6% in the low-dose group, and 70 ± 4% in the high-dose group. The change in tension during recovery was not significant in the control or low-dose groups. However, there was partial recovery in the high-dose group. In conclusion, in this preparation, oxygen radical scavengers did not delay the development of decreased muscle tension.Key words: muscle fatigue, oxygen free radicals, resistance, flow.

Dose-Dependent Hyperkalemia Among Hospitalized, HIV-Infected Patients Receiving Sulfamethoxazole/Trimethoprim

2020 ◽  
Vol 54 (9) ◽  
pp. 852-857
Author(s):  
Celeste R. Caulder ◽  
Caitlin S. Kocherla ◽  
Zaina P. Qureshi ◽  
Joseph Magagnoli ◽  
P. Brandon Bookstaver
Keyword(s):  
Dose Group ◽  
Low Dose ◽  
Elevated Serum ◽  
High Dose Group ◽  
Drug Event ◽  
High Dose ◽  
Inclusion Criteria ◽  
Severe Hyperkalemia ◽  
Nephrotoxic Drugs ◽  
Dose Dependent

Background: Sulfamethoxazole-trimethoprim (SXT) therapy is commonly used in HIV-infected patients and is associated with hyperkalemia and elevated serum creatinine (SCr). Objective: The purpose of this study was to examine the frequency of hyperkalemia and elevated SCr in hospitalized, HIV-infected patients receiving SXT. Methods: This was a retrospective, single-center cohort study. HIV-infected hospitalized patients receiving a minimum of 3 consecutive days of SXT were included. Patients were grouped according to high dose (≥10 mg/kg/d) and low dose (<10 mg/kg/d) trimethoprim. The primary end point was the frequency of hyperkalemia, severe hyperkalemia, and elevated SCr. Secondary end points included an evaluation of concomitant potassium-altering medications and concomitant nephrotoxic drugs. Results: A total of 100 consecutive patients were selected from all possible patients who met inclusion criteria. Overall, 47 patients experienced at least 1 adverse drug event (ADE) of either hyperkalemia or increased SCr, with 20 patients experiencing these ADEs in the low-dose group and 27 patients experiencing these ADEs in the high-dose group ( P = 0.229). The ADEs of hyperkalemia or increased SCr occurred after a shorter period (5.5 vs 8.7 days) in the high-dose group ( P = 0.049). Overall frequency of elevated SCr was 24% and of elevated serum K was 36%. Hyperkalemia requiring a therapeutic intervention occurred in 12 patients in the high-dose group compared with 2 in the low-dose group ( P = 0.009). Conclusion and Relevance: Rates of elevated SCr and hyperkalemia in hospitalized HIV-infected patients receiving SXT are significant. Hyperkalemia requiring intervention is more common in patients receiving high-dose SXT.

The effects of etomidate on cerebral metabolism and blood flow in a canine model for hypoperfusion

1991 ◽  
Vol 74 (2) ◽  
pp. 263-269 ◽  
Author(s):  
R. Tyler Frizzell ◽  
Yves J. Meyer ◽  
D. John Borchers ◽  
Bradley E. Weprin ◽  
Elizabeth C. Allen ◽  
...  
Keyword(s):  
Blood Flow ◽  
Dose Group ◽  
Low Dose ◽  
Cerebral Metabolism ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
High Dose Group ◽  
High Dose ◽  
Cerebral Oxygen ◽  
The Mean

✓ The effects of etomidate, a nonbarbiturate cerebral metabolic depressant, on cerebral metabolism and blood flow were studied in 29 dogs during cerebral hypoperfusion. Three groups of animals were studied during a 45-minute normotensive and a 30-minute hypotensive period: 10 control animals without etomidate, 11 animals receiving a 0.1-mg/kg etomidate bolus followed by an infusion of 0.05 mg/kg/min etomidate (low-dose group), and eight animals receiving doses of etomidate sufficient to suppress electroencephalographic bursts (high-dose group). The mean arterial pressure fell to similar levels (p < 0.05) during hypotension in all three groups (40 ± 5, 38 ± 3, and 27 ± 6 mm Hg, respectively). The mean cerebral oxygen extraction fraction rose (p < 0.05) from 0.23 ± 0.02 to 0.55 ± 0.08 in the five control animals tested and from 0.33 ± 0.02 to 0.53 ± 0.02 in the seven animals tested in the low-dose group, but did not increase (p > 0.05) in the four animals tested in the high-dose group (0.24 ± 0.03 to 0.23 ± 0.05). Mean cerebral blood flow levels decreased in all groups during hypotension (p < 0.05): 42 ± 3 to 21 ±4 ml/100 gm/min (52% ± 12% decrease) in the five animals tested in the control group, 60 ± 8 to 24 ± 6 ml/100 gm/min (56% ± 13% decrease) in the four animals tested in the low-dose group, and 55 ± 8 to 22 ± 3 ml/100 gm/min (60% ± 4% decrease) in the four animals tested in the high-dose group. In summary, the cerebral oxygen extraction fraction increased in the control animals and low-dose recipients during hypotension, suggesting the presence of threatened cerebral tissue. In contrast, the cerebral oxygen extraction did not change during hypotension when high-dose etomidate was administered. It is concluded that high-dose etomidate may preserve the cerebral metabolic state during hypotension in the present model.

scholarly journals Newly Developed Recombinant Antithrombin Protects the Endothelial Glycocalyx in an Endotoxin-Induced Rat Model of Sepsis

2020 ◽  
Vol 22 (1) ◽  
pp. 176
Author(s):  
Toshiaki Iba ◽  
Jerrold H. Levy ◽  
Koichiro Aihara ◽  
Katsuhiko Kadota ◽  
Hiroshi Tanaka ◽  
...  
Keyword(s):  
Dose Group ◽  
Low Dose ◽  
Leukocyte Adhesion ◽  
Endothelial Glycocalyx ◽  
High Dose Group ◽  
Control Group ◽  
High Dose ◽  
Protective Effects ◽  
Circulating Levels

(1) Background: The endothelial glycocalyx is a primary target during the early phase of sepsis. We previously reported a newly developed recombinant non-fucosylated antithrombin has protective effects in vitro. We further evaluated the effects of this recombinant antithrombin on the glycocalyx damage in an animal model of sepsis. (2) Methods: Following endotoxin injection, in Wistar rats, circulating levels of hyaluronan, syndecan-1 and other biomarkers were evaluated in low-dose or high-dose recombinant antithrombin-treated animals and a control group (n = 7 per group). Leukocyte adhesion and blood flow were evaluated with intravital microscopy. The glycocalyx was also examined using side-stream dark-field imaging. (3) Results: The activation of coagulation was inhibited by recombinant antithrombin, leukocyte adhesion was significantly decreased, and flow was better maintained in the high-dose group (both p < 0.05). Circulating levels of syndecan-1 (p < 0.01, high-dose group) and hyaluronan (p < 0.05, low-dose group; p < 0.01, high-dose group) were significantly reduced by recombinant antithrombin treatment. Increases in lactate and decreases in albumin levels were significantly attenuated in the high-dose group (p < 0.05, respectively). The glycocalyx thickness was reduced over time in control animals, but the derangement was attenuated and microvascular perfusion was better maintained in the high-dose group recombinant antithrombin group (p < 0.05). (4) Conclusions: Recombinant antithrombin maintained vascular integrity and the microcirculation by preserving the glycocalyx in this sepsis model, effects that were more prominent with high-dose therapy.

scholarly journals Recombinant Human Thyrotropin-Stimulated Radioiodine Therapy in Patients with Multinodular Goiters: A Meta-Analysis of Randomized Controlled Trials

2020 ◽  
Vol 52 (12) ◽  
pp. 841-849
Author(s):  
Chunmei Xu ◽  
Ping Wang ◽  
Huikai Miao ◽  
Tianyue Xie ◽  
Xiaojun Zhou ◽  
...  
Keyword(s):  
Fixed Effects ◽  
Dose Group ◽  
Low Dose ◽  
Radioiodine Therapy ◽  
Meta Analysis ◽  
High Dose Group ◽  
High Dose ◽  
Fixed Effects Model ◽  
Recombinant Human Thyrotropin

AbstractA potential reduction of goiter volume (GV) of recombinant human thyrotropin (rhTSH) on multinodular goiters (MNG) was previously reported but controversial. Hence we conducted a meta-analysis to estimate the effect of rhTSH-stimulated radioiodine therapy in patients with MNG. PubMed, Cochrane, CNKI, VIP, and Wanfang databases were searched. Mean difference (MD) and odds ratios with 95% confidence intervals (95% CI) were derived by using an inverse variance random-effects model and fixed-effects model, respectively. Six studies (n=237) were involved in the analysis. For 12 months follow up, high dose (>0.1 mg) of rhTSH significantly reduced GV (MD=17.61; 95% CI=12.17 to 23.04; p<0.00001) compared with placebo. No effective pooled results of low dose of rhTSH (<0.1 mg) were applicable for only one study included. For 6 months follow up, the source of heterogeneity was determined by subgroup and sensitivity analysis. High dose group showed vast improvement in GV reduction (MD=16.62; 95% CI=1.34 to 31.90; p=0.03). The reduction of low dose group compared with placebo was inferior to high dose group. No available data were obtained to assess the influence of rhTSH after 36 months follow up for the only included study. Hypothyroidism incidence was higher for rhTSH group. No publication bias was seen. High dose of rhTSH treatment-stimulated radioactive 131I therapy after 6 months and 12 months follow up had a better effect in reducing GV, but with higher incidence of hypothyroidism. Owing to the limited methodological quality, more clinical researches are warranted in the future.

Effect of Different Doses of Propofol and Nerve block Combined with General Anesthesia on The Intraoperative Anesthesia and Postoperative Awakening and Cognitive Function in Elderly Patients with Knee Osteoarthritis

2021 ◽  
Vol 7 (4) ◽  
pp. 697-705
Author(s):  
Jianhui Ma ◽  
Meimei Pang ◽  
Xin Ding ◽  
Shirong Fang ◽  
Lichao Chu
Keyword(s):  
Cognitive Function ◽  
Elderly Patients ◽  
General Anesthesia ◽  
Nerve Block ◽  
Dose Group ◽  
Low Dose ◽  
High Dose Group ◽  
High Dose ◽  
Knee Oa ◽  
Different Doses

Objective. To explore the effect of different doses of propofol and nerve block combined with general anesthesia on the intraoperative anesthesia and postoperative awakening and cognitive function in elder patients with knee osteoarthritis (OA). Methods. According to the inclusion criteria for research object, we selected 98 elderly patients with knee OA who needed surgery and were admitted to our hospital from January 2019 to January 2021 for the study. Patients were divided into the low dose group (given 2 mg/kg propofol by pumping under constant speed during surgery) and the high dose group (given 4 mg/kg propofol by pumping during surgery) by the number table method to compare their indicators including the intraoperative anesthesia effect, with 49 cases in each group. Results. No between-group difference was shown in the anesthesia time and postoperative VAS scores, but the awakening time of the low dose group was significantly shorter than that of the high dose group (P<0.05); the differences in heart rate (HR) values at various time points between the two groups were not obvious, but the high dose group obtained significantly higher HR values at T4 than the low dose group; the mean arterial pressure (MAP) values of both groups were significantly reduced at Ti and then returned to the level before anesthesia (P>0.05); the bispectral index scores (BIS) of both groups experienced a marked drop at Ti and then recovered gradually, but failed to return to the level at T0 till the end, and a between-group difference in BIS indexes presented at Ti; the plasma corticosterone (CORT) concentration at Ti of both groups were significantly lowered and then returned to the level at T0, with no between-group difference; and compared with the low dose group, the high dose group achieved slightly lower mini-mental state examination (MMSE) scores at 24-72 h after surgery, with no significant difference between them (P>0.05). Conclusion. The therapy of different doses of propofol and nerve block combined with general anesthesia has no significant effect on the cognitive function in elderly knee OA patients after surgery. With the nerve block improving the analgesic effect, a low dose of propofol is good for the postoperative awakening of patients. Different doses of propofol inhibited the stress response to a different degree and produced good anesthesia outcomes in elderly patients, but comparatively speaking, a low-dose propofol ensures more smooth indexes and less effect on the intraoperative hemodynamics.

scholarly journals Comparison of the in-vivo Effect of Two Tranexamic Acid Doses on Fibrinolysis Parameters in Adults Undergoing Valvular Cardiac Surgery with Cardiopulmonary Bypass - A Pilot Investigation

2020 ◽  
Author(s):  
Zhen-feng ZHOU ◽  
Wen Zhai ◽  
Li-na YU ◽  
Kai SUN ◽  
Li-hong SUN ◽  
...  
Keyword(s):  
Cardiac Surgery ◽  
Placebo Group ◽  
Cardiopulmonary Bypass ◽  
Plasminogen Activator ◽  
Dose Group ◽  
Low Dose ◽  
High Dose Group ◽  
High Dose ◽  
Pai 1

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.

scholarly journals Research on the Effects of the Extract of Polygala fallax Hemsl on Sex Hormones and ?-EP in Perimenopausal Rat Models

2020 ◽  
Vol 4 (3) ◽  
Author(s):  
Siyuan Yang ◽  
Zhiyong Cao ◽  
Jiabao Chen ◽  
Gang Fang
Keyword(s):  
Menstrual Cycle ◽  
Sex Hormones ◽  
Dose Group ◽  
Low Dose ◽  
Normal Group ◽  
Dose Effect ◽  
High Dose Group ◽  
High Dose ◽  
Model Group ◽  
Rat Models

Objective: To study the effects of the ethnic medicine Polygala fallax Hemsl with Guangxi characteristics on the sex hormones and ?-EP in research objective perimenopausal rat models. Methods: 40 female SPF rats were randomly divided into 4 groups, including the normal, model, high-dose and low-dose groups. Rats of three groups except for the normal one were treated with perimenopausal modelling through the method of subcutaneous injection of compound 4-VCD for 15 consecutive days. Rats of the normal and model group were normally fed without any treatment. Rats of the high-dose and low-dose groups were administered by high- and low-dose intragastric administration of the extract of Polygala fallax Hemsl. According to the menstrual cycle of the vaginal smear of the rat, each menstrual cycle is a course of treatment and 6 consecutive courses of treatment would be given. The indexes of serum sex hormones (E2, FSH, LH) and ?-EP of rats in each group were observed after treatment. Results: After the treatment of 6 cycles, for the levels of ?-EP and E2, the model group was lowest (P<0.05), the normal group was highest (P<0.05); and the high-dose group was higher than the low-dose group; For the levels of FSH and LH, the normal group was lowest (P<0.05), the model group was highest (P<0.05), and the high-dose group was lower than the low-dose group. Conclusion: Guangxi characteristic national medicine Polygala fallax Hemsl can effectively improve the levels of serum sex hormones and ?-EP in perimenopausal rat models and relieve the related symptoms with a certain dose-effect relationship.

scholarly journals Efficacy and Safety of Daikenchuto for Constipation and Dose-Dependent Differences in Clinical Effects

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Tatsuya Hirose ◽  
Yasutaka Shinoda ◽  
Ayaka Kuroda ◽  
Aya Yoshida ◽  
Machiko Mitsuoka ◽  
...  
Keyword(s):  
Dose Group ◽  
Low Dose ◽  
Clinical Laboratory ◽  
Laboratory Data ◽  
High Dose ◽  
Clinical Effects ◽  
Efficacy And Safety ◽  
Watery Stool ◽  
Group 4 ◽  
Dose Dependent

Background. Daikenchuto (DKT) is a Kampo medicine used for the treatment of constipation. In this study, we evaluated the effectiveness of DKT against constipation. Patients and Methods. Thirty-three patients administered DKT for constipation were selected and divided into low-dose (7.5 g DKT; n=22) and high-dose (15 g DKT; n=11) groups. We retrospectively evaluated weekly defaecation frequency, side effects, and clinical laboratory data. Results. Median defaecation frequencies after DKT administration (5, 5.5, 5, and 8 for the first, second, third, and fourth weeks, resp.) were significantly higher than that before DKT administration (2) in all 33 cases (P<0.01). One case (3%) of watery stool, one case of loose stools (3%), and no cases of abdominal pain (0%) were observed. Median defaecation frequencies in the high-dose group (7 and 9) were significantly higher than those in the low-dose group (4 and 3) in the first (P=0.0133) and second (P=0.0101) weeks, respectively. There was no significant change in clinical laboratory values. Conclusion. We suggest that DKT increases defaecation frequency and is safe for treating constipation.

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