scholarly journals Pharmacokinetics and Pharmacodynamics Evaluation of Tramadol in Thermoreversible Gels

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Juliana Zampoli Boava Papini ◽  
Cíntia Maria Saia Cereda ◽  
José Pedrazzoli Júnior ◽  
Silvana Aparecida Calafatti ◽  
Daniele Ribeiro de Araújo ◽  
...  

We evaluated pharmacokinetics (PK) and pharmacodynamics (PD) induced by new formulations of tramadol (TR) in thermoreversible gels. The poloxamer- (PL-) tramadol systems were prepared by direct dispersion of the drug in solutions with PL 407 and PL 188. The evaluated formulations were as follows: F1: TR 2% in aqueous solution and F2: PL 407 (20%) + PL 188 (10%) + TR 2%; F3: PL 407 (25%) + PL 188 (5%) + TR 2%; F4: PL 407 (20%) + TR 2%. New Zealand White rabbits were divided into four groups (n=6) and treated by subcutaneous route with F1, F2, F3, or F4 (10 μg·kg−1). PK evaluation used TR and M1 plasma levels. PD evaluation was performed with the measurement of both pupils’ diameters. F2 showed higher TR plasma concentration after 180 minutes and presented lower M1 concentrations at almost all evaluated periods. Areas under the curve (ASC0–480 and ASC0–∞) and clearance of F2 presented differences compared to F1. F2 presented significant correlation (Pearson correlation) between the enhancement of TR and M1 concentrations and the decrease of pupil size (miosis). Thus, F2 was effective in altering pharmacokinetics and pharmacodynamics effects of TR.

1970 ◽  
Vol 117 (2) ◽  
pp. 263-265 ◽  
Author(s):  
W. Taylor

1. [4-14C]Cortisone was administered to anaesthetized male and female New Zealand White rabbits as a single injection or as a 45–60min infusion. 2. The method of administration of the steroid did not significantly affect the total excretion of radioactivity in bile and urine [83.8±10.8%(s.d.)]. 3. The mean ratio of metabolites in urine to those in bile was 0.97±0.23% (range 0.64–1.3). 4. When bile and urine samples were hydrolysed successively by β-glucuronidase, cold acid and hot acid, neutral metabolites extracted by ethyl acetate–ether were found mainly after hydrolysis by β-glucuronidase. 5. An approximately equal proportion of the dose was converted into substances not extractable from alkaline aqueous solution after hydrolysis.


2020 ◽  
Vol 41 (7) ◽  
pp. 307-316
Author(s):  
Justyna Warzybok ◽  
Agnieszka Bienert ◽  
Agnieszka Borsuk‐De Moor ◽  
Włodzimierz Płotek ◽  
Karolina Kulińska ◽  
...  

Author(s):  
Sidney D. Kobernick ◽  
Edna A. Elfont ◽  
Neddra L. Brooks

This cytochemical study was designed to investigate early metabolic changes in the aortic wall that might lead to or accompany development of atherosclerotic plaques in rabbits. The hypothesis that the primary cellular alteration leading to plaque formation might be due to changes in either carbohydrate or lipid metabolism led to histochemical studies that showed elevation of G-6-Pase in atherosclerotic plaques of rabbit aorta. This observation initiated the present investigation to determine how early in plaque formation and in which cells this change could be observed.Male New Zealand white rabbits of approximately 2000 kg consumed normal diets or diets containing 0.25 or 1.0 gm of cholesterol per day for 10, 50 and 90 days. Aortas were injected jin situ with glutaraldehyde fixative and dissected out. The plaques were identified, isolated, minced and fixed for not more than 10 minutes. Incubation and postfixation proceeded as described by Leskes and co-workers.


Author(s):  
W.P. De Lange

The Greenhouse Effect acts to slow the escape of infrared radiation to space, and hence warms the atmosphere. The oceans derive almost all of their thermal energy from the sun, and none from infrared radiation in the atmosphere. The thermal energy stored by the oceans is transported globally and released after a range of different time periods. The release of thermal energy from the oceans modifies the behaviour of atmospheric circulation, and hence varies climate. Based on ocean behaviour, New Zealand can expect weather patterns similar to those from 1890-1922 and another Little Ice Age may develop this century.


Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 880
Author(s):  
Tuanyuan Shi ◽  
Xinlei Yan ◽  
Hongchao Sun ◽  
Yuan Fu ◽  
Lili Hao ◽  
...  

Cyniclomyces guttulatus is usually recognised as an inhabitant of the gastrointestinal (GI) tract in rabbits. However, large numbers of C. guttulatus are often detected in the faeces of diarrhoeic rabbits. The relationship of C. guttulatus with rabbit diarrhoea needs to be clearly identified. In this study, a C. guttulatus Zhejiang strain was isolated from a New Zealand White rabbit with severe diarrhoea and then inoculated into SPF New Zealand white rabbits alone or co-inoculated with Eimeriaintestinalis, another kind of pathogen in rabbits. Our results showed that the optimal culture medium pH and temperature for this yeast were pH 4.5 and 40–42 °C, respectively. The sequence lengths of the 18S and 26S ribosomal DNA fragments were 1559 bp and 632 bp, respectively, and showed 99.8% homology with the 18S ribosomal sequence of the NRRL Y-17561 isolate from dogs and 100% homology with the 26S ribosomal sequence of DPA-CGR1 and CGDPA-GP1 isolates from rabbits and guinea pigs, respectively. In animal experiments, the C. guttulatus Zhejiang strain was not pathogenic to healthy rabbits, even when 1 × 108 vegetative cells were used per rabbit. Surprisingly, rabbits inoculated with yeast showed a slightly better body weight gain and higher food intake. However, SPF rabbits co-inoculated with C. guttulatus and E. intestinalis developed more severe coccidiosis than rabbits inoculated with C. guttulatus or E. intestinalis alone. In addition, we surveyed the prevalence of C. guttulatus in rabbits and found that the positive rate was 83% in Zhejiang Province. In summary, the results indicated that C. guttulatus alone is not pathogenic to healthy rabbits, although might be an opportunistic pathogen when the digestive tract is damaged by other pathogens, such as coccidia.


2021 ◽  
pp. neurintsurg-2020-017261
Author(s):  
Stefan Wanderer ◽  
Basil Erwin Grüter ◽  
Fabio Strange ◽  
Gwendoline Boillat ◽  
Sivani Sivanrupan ◽  
...  

BackgroundAneurysm wall degeneration is linked to growth and rupture. To address the effect of aspirin (ASA) on aneurysm formation under various wall conditions, this issue was analyzed in a novel rabbit bifurcation model.MethodsBifurcation aneurysms created in 45 New Zealand White rabbits were randomized to vital (n=15), decellularized (n=13), or elastase-degraded (n=17) wall groups; each group was assigned to a study arm with or without ASA. At follow-up 28 days later, aneurysms were evaluated for patency, growth, and wall inflammation at macroscopic and histological levels.Results36 rabbits survived to follow-up at the end of the trial. None of the aneurysms had ruptured. Patency was visualized in all aneurysms by intraoperative fluorescence angiography and confirmed in 33 (92%) of 36 aneurysms by MRI/MRA. Aneurysm size was significantly increased in the vital (without ASA) and elastase-degraded (with and without ASA) groups. Aneurysm thrombosis was considered complete in three (50%) of six decellularized aneurysms without ASA by MRI/MRA. Locoregional inflammation of the aneurysm complex was significantly reduced in histological analysis among all groups treated with ASA.ConclusionASA intake prevented inflammation of both the periadventitial tissue and aneurysm wall, irrespective of initial wall condition. Although ASA prevented significant growth in aneurysms with vital walls, this preventive effect did not have an important role in elastase-degraded pouches. In possible translation to the clinical situation, ASA might exert a potential preventive effect during early phases of aneurysm formation in patients with healthy vessels but not in those with highly degenerative aneurysm walls.


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