A Proposal for New Strategies in Dose Selection for 26-Week Tg.Rash2 Carcinogenicity Studies

2021 ◽  
pp. 109158182110033
Author(s):  
Madhav G. Paranjpe ◽  
Tom J. Vidmar ◽  
Melissa D. Denton ◽  
Reem H. Elbekai ◽  
Peter C. Mann ◽  
...  
Keyword(s):  
Dose Group ◽  
Body Weight Gain ◽  
Dose Range ◽  
High Dose ◽  
Dose Selection ◽  
Test Article ◽  
Range Finding ◽  
Body Weights ◽  
High Doses ◽  
New Strategies

Our experience indicates that extrapolation of doses from the maximum tolerated doses (MTD) derived from 4-week dose range finding (DRF) studies conducted in CByB6F1 may overpredict tolerability and undermine utility of the high-dose groups in 26-week carcinogenicity studies conducted in Tg.rasH2. In the 26-week carcinogenicity studies conducted in Tg.rasH2 mice, we analyzed the initial body weights, food consumption (FC), terminal body weights, body weight gain (BWG), mortality, and tumor incidence for vehicle and test article–treated dose groups for 26 studies conducted from 2014 to 2018. Although not statistically significant compared to the control dose group, the % BWG decreased in male mice of mid- and high-dose groups by >10%, whereas in females there were no differences. The mortality increased in a statistically significant manner for medium and high doses of males. In female mice, the mortality increased in the high-dose group but not in a statistically significant manner. When the cause of death (COD) was analyzed in all dose groups of both sexes, the COD due to tumors was highest in the control groups, whereas it was lowest in high-dose groups of both sexes. At the same time, the COD due to undetermined causes, which is possible indication of test article–induced toxicity, was highest in high-dose groups of both sexes. These findings together indicate that MTD derived from earlier DRF studies was exceeded when applied to 26-week carcinogenicity studies and did not serve any purpose in the outcome of these studies.

scholarly journals Tg.rasH2 Mice and not CByB6F1 Mice Should Be Used for 28-Day Dose Range Finding Studies Prior to 26-Week Tg.rasH2 Carcinogenicity Studies

2017 ◽  
Vol 36 (4) ◽  
pp. 287-292 ◽  
Author(s):  
Madhav G. Paranjpe ◽  
Jessica Belich ◽  
Tom J. Vidmar ◽  
Reem H. Elbekai ◽  
Marie McKeon ◽  
...  
Keyword(s):  
Selection Process ◽  
Dose Range ◽  
Maximum Tolerated Dose ◽  
High Dose ◽  
Dose Selection ◽  
Range Finding ◽  
Body Weights ◽  
Vehicle Test ◽  
High Doses ◽  
Dose Levels

Our recent retrospective analysis of data, collected from 29 Tg.rasH2 mouse carcinogenicity studies, determined how successful the strategy of choosing the high dose for the 26-week studies was based on the estimated maximum tolerated dose (EMTD) derived from earlier 28-day dose range finding (DRF) studies conducted in CByB6F1 mice. Our analysis demonstrated that the high doses applied at EMTD in the 26-week Tg.rasH2 studies failed to detect carcinogenic effects. To investigate why the dose selection process failed in the 26-week carcinogenicity studies, the initial body weights, terminal body weights, body weight gains, food consumption, and mortality from the first 4 weeks of 26-week studies with Tg.rasH2 mice were compared with 28-day DRF studies conducted with CByB6F1 mice. Both the 26-week and the earlier respective 28-day studies were conducted with the exact same vehicle, test article, and similar dose levels. The analysis of our results further emphasizes that the EMTD and subsequent lower doses, determined on the basis of the 28-day studies in CByB6F1 mice, may not be an accurate strategy for selecting appropriate dose levels for the 26-week carcinogenicity studies in Tg.rasH2 mice. Based on the analysis presented in this article, we propose that the Tg.rasH2 mice and not the CByB6F1 mice should be used in future DRF studies. The Tg.rasH2 mice demonstrate more toxicity than the CByB6F1 mice, possibly because of their smaller size compared to CByB6F1 mice. Also, the Tg.rasH2 males appear to be more sensitive than the female Tg.rasH2 mice.

scholarly journals Evaluation of the BDNF, NGF, NT3 and NT4 Genes Expressions in the Brains of Neonatal Mice with Hypothyroidism

2017 ◽  
Vol 7 (1) ◽  
pp. 171
Author(s):  
Hamid Reza Adeli Bhroz ◽  
Kazem Parivar ◽  
Iraj Amiri ◽  
Nasim Hayati Roodbari
Keyword(s):  
Dose Group ◽  
Low Dose ◽  
Pure Water ◽  
Intervention Group ◽  
Control Group ◽  
High Dose ◽  
Endocrine Glands ◽  
Blood Samples ◽  
High Doses ◽  
The Brain

Background and Aim: Thyroid is one of the endocrine glands, (T3 and T4) play a significant role in the development of prenatal brain and the following stages. The study aimed to evaluate the effect of hypothyroidism on the amount of expression of NT4, NT3, nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in brain of one-day rat neonates with hypothyroidism.Materials and Methods: In total, 25 mature mice of Albino NMRI race were selected after mating, divided into three group, control, as well as low-dose and high-dose intervention groups. Samples of the control group received pure water during pregnancy, whereas subjects of the intervention group with low and high doses of the medication were administered with 20 mg and 100 mg methimazole powder (dissolved in 100 cc water), respectively. After child delivery, blood samples were obtained from mother mice to determine the level of T3 and T4 in blood serum. Following that, the brain of one-day mice were removed by surgery and assessed to determine the amount of expression of NT4, NT3, NGF and BDNF using the complete kit of RT-PCR.Results: Levels of T4 and T3 in the control group were 28 ug/dl and 1.59 ug/dl, respectively. In the low-dose intervention group, the amounts of the mentioned hormones were 8 ug/dl and 0.85 ug/dl, significantly, indicating a significant reduction in the expression of NT4, NT3, NGF and BDNF genes, compared to the control group. Moreover, T4 and T3 were 6 ug/dl and 0.79 ug/dl in the high-dose group, respectively, conveying a significant decrease in the expression of NT4, NT3, NGF and BDNF genes, compared to the control group (P<0.05).

scholarly journals CD8+ T Cells Mediate Recovery andImmunopathology in West Nile VirusEncephalitis

2003 ◽  
Vol 77 (24) ◽  
pp. 13323-13334 ◽  
Author(s):  
Yang Wang ◽  
Mario Lobigs ◽  
Eva Lee ◽  
Arno Müllbacher
Keyword(s):  
T Cells ◽  
Dose Group ◽  
Low Dose ◽  
Neuronal Degeneration ◽  
High Dose ◽  
West Nile ◽  
Activation Markers ◽  
High Doses ◽  
The Brain ◽  
Deficient Mice

ABSTRACT C57BL/6J mice infected intravenously with the Sarafend strain of West Nile virus (WNV) develop a characteristic central nervous system (CNS) disease, including an acute inflammatory reaction. Dose response studies indicate two distinct kinetics of mortality. At high doses of infection (108 PFU), direct infection of the brain occurred within 24 h, resulting in 100% mortality with a 6-day mean survival time (MST), and there was minimal destruction of neural tissue. A low dose (103 PFU) of infection resulted in 27% mortality (MST, 11 days), and virus could be detected in the CNS 7 days postinfection (p.i.). Virus was present in the hypogastric lymph nodes and spleens at days 4 to 7 p.i. Histology of the brains revealed neuronal degeneration and inflammation within leptomeninges and brain parenchyma. Inflammatory cell infiltration was detectable in brains from day 4 p.i. onward in the high-dose group and from day 7 p.i. in the low-dose group, with the severity of infiltration increasing over time. The cellular infiltrates in brain consisted predominantly of CD8+, but not CD4+, T cells. CD8+ T cells in the brain and the spleen expressed the activation markers CD69 early and expressed CD25 at later time points. CD8+ T-cell-deficient mice infected with 103 PFU of WNV showed increased mortalities but prolonged MST and early infection of the CNS compared to wild-type mice. Using high doses of virus in CD8-deficient mice leads to increased survival. These results provide evidence that CD8+ T cells are involved in both recovery and immunopathology in WNV infection.

scholarly journals SUN-042 Low Dose Cyproterone Acetate for the Treatment of Transgender Women - a Retrospective Study

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Naomi Even-Zohar ◽  
Yael Sofer ◽  
Iris Yaish ◽  
Merav Serebro ◽  
Karen Tordjman ◽  
...  
Keyword(s):  
Cyproterone Acetate ◽  
Dose Group ◽  
Low Dose ◽  
Dose Range ◽  
Hormonal Treatment ◽  
Transgender Women ◽  
High Dose ◽  
Historical Cohort ◽  
Treatment Groups ◽  
First Time

Abstract Introduction : Transgender women with intact gonads receive lifelong hormonal treatment in order to suppress physiologic androgen production. Cyproterone acetate (CA) is the most comon antiandrogenic drug prescribed for this indication in Europe, with a dose range between 25-100 mg/day. Aim: To assess the effectiveness and safety of low dose (&lt;20 mg/day), compared with high dose (&gt;50 mg/day) CA treatment. Methods: Historical cohort study of transgender women treated in our department between January 2000 and October 2018. Results: There were 42 transgender women in the low dose group (LDG) and 32 in the high dose group (HDG). Age (27.9 ± 1.6 vs.28.9 ± 1.7 years) and follow up time (16.2 ± 2.2 vs. 20.1 ± 2.1 months) were similar in the LDG and HDG, respectively. At the last available visit, testosterone levels were effectively and similarly suppressed in both treatment groups (0.6 ± 0.1 vs 0.8 ± 0.3 nmol/l; p=0.37, for LDG and HDG respectively). Prolactin (659 ± 64 vs 486 ± 42 mIU/ml, p=0.02), LDL cholesterol (96.1 ± 5 vs 78.5 ± 4 mg/dl, p= 0.02) and triglycerides (93.3 ± 9 vs 69 ± 5 mg/dl; p=0.02) were higher in the HDG compared with LDG respectively. Side effects were common in the HDG (four cases of increased liver enzymes, one case of pulmonary embolism and one case of sudden death). Conclusion: We show for the first time that anti-androgenic treatment of transgender women with low dose CA is as effective as high dose treatment, but safer. We suggest incorporation of this observation in future guidelines.

Influence of in utero di-n-hexyl phthalate and di-cyclohexyl phthalate exposure on the endocrine glands and T3, T4, and TSH hormone levels of male and female rats: Postnatal outcomes

2020 ◽  
Vol 36 (6) ◽  
pp. 399-416
Author(s):  
Nurhayat Barlas ◽  
Emre Göktekin ◽  
Gözde Karabulut
Keyword(s):  
Pituitary Gland ◽  
Dose Group ◽  
Female Rats ◽  
Male Rats ◽  
High Dose ◽  
Hormone Levels ◽  
Male And Female Rats ◽  
Endocrine Organs ◽  
Body Weights ◽  
Juvenile Stages

The present study was designed to evaluate the effects of di- n-hexyl phthalate (DHP) and di-cyclohexyl phthalate (DCHP) on endocrine organs in rats. Oil control, 20-, 100-, and 500 mg/kg dose groups were selected and administered to pregnant rats on gestational days 6–19 by oral gavage. The neonatal stages of rats continued until postnatal day 20 and the- juvenile stages of rats continued until postnatal day of 32. The rats were allowed to mature until the neonatal and juvenile stages and there after, they were divided into four groups corresponding to the treatment levels. Body and organ weights were recorded, serum was collected, and thyroid, pancreas, pituitary gland, and adrenal gland were removed. There was a decrease in body weights in the 20- and 500mg/kg DHP and in the 20-mg/kg DCHP dose groups in neonatal male rats. In contrast, for female rats, there was an increase in body weights in the 100-mg/kg DCHP dose group and there was a decrease in body weights in the 500-mg/kg DHP dose group. Body weights were increased at 20 and 500 mg/kg in the DHP-exposed juvenile male rats. Serum thyroid-stimulating hormone (TSH) levels were increased in neonatal male rats, while they were increased in the 100-mg/kg DHP group of neonatal and juvenile female rats. Serum triiodothyronine (T3) levels were increased at the high dose of DHP for neonatal male rats and at the low and high dose levels of DCHP for female rats. Serum thyroxine (T4) levels were increased in neonatal rats for DHP. Also, some histopathological changes were observed in the thyroid, pancreas, adrenal, and pituitary gland. In conclusion, it was shown that DHP and DCHP caused negative effects on T3, T4, and TSH hormone levels.

Effects of long-term continuous GnRH administration on the pituitary–gonadal axis in Eld's deer stags (Cervus eldi thamin)

1995 ◽  
Vol 73 (9) ◽  
pp. 1609-1619 ◽  
Author(s):  
S. L. Monfort ◽  
J. L. Brown ◽  
T. C. Wood ◽  
M. Bush ◽  
L. R. Williamson ◽  
...  
Keyword(s):  
Dose Group ◽  
Low Dose ◽  
High Dose ◽  
Fertile Period ◽  
Nonbreeding Season ◽  
Testosterone Secretion ◽  
High Doses ◽  
Seasonal Decline ◽  
Seasonally Breeding

Eld's deer stags (Cervus eldi thamin) (in groups of three) were continuously administered gonadotropin-releasing hormone (GnRH) in control, low, medium, or high doses (0, 20.1 ± 0.7, 83.3 ± 2.6, and 292.9 ± 4.9 ng∙kg−1∙d−1, respectively) via osmotic minipumps for ~80 d to investigate the potential for precociously reactivating the pituitary–testicular axis during the nonbreeding season. Secretory patterns of LH, FSH, and testosterone concentrations were qualitatively similar among treatments. However, in the low-dose group, basal LH and FSH concentrations were both increased (p < 0.05) and pituitary responsiveness to a superimposed GnRH challenge was augmented (p < 0.05) after 12 weeks of treatment compared with all other groups. Despite these endocrine changes, continuous low-dose GnRH administration was not effective for precociously inducing testicular activity in this seasonally breeding species. High-dose GnRH administration initially induced a transient increase in LH, FSH, and testosterone secretion and delayed, but did not prevent, the seasonal decline in spermatogenesis. After 6–12 weeks of high-dose GnRH administration, however, attenuated pituitary responsiveness appeared to delay the normal seasonal reactivation of the pituitary–gonadal axis. In conclusion, prolonged, continuous low-dose GnRH administration did not effectively translate into a precocious onset of testicular activity; therefore, this specific approach is unlikely to be useful for prolonging the fertile period in this seasonally breeding species.

scholarly journals Effect of gamma-irradiation on the properties of aluminum dihydrogen triphosphate

2017 ◽  
Vol 82 (10) ◽  
pp. 1111-1121 ◽  
Author(s):  
Weiqiang Song ◽  
Qinghuan Song ◽  
Longchao Wu ◽  
Lantao Yang
Keyword(s):  
Thermal Analysis ◽  
Corrosion Resistance ◽  
Gamma Irradiation ◽  
Electrochemical Impedance ◽  
Dose Range ◽  
Xrd Analysis ◽  
High Dose ◽  
Crystal Transition ◽  
Steel Panels ◽  
High Doses

The effect of gamma irradiation on the properties of aluminum dihydrogen triphosphate (ADTP) in the dose range of 0 to 150 kGy was studied by X-ray diffraction (XRD) analysis, thermal analysis, acid?base titration, electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). Although the XRD and SEM results indicated that there were no significant effects on the crystal structure and the surface morphology of ADTP, thermal analysis revealed that the crystal transition of Al(PO3)3 from Type-B to Type-A did not occur at a high temperature in irradiated ADTP. EIS results showed that high-dose gamma irradiation (100 kGy and 150 kGy, 60Co) improved the corrosion inhibition ability of ADTP on tinplate steel. SEM was used to investigate the surface of tinplate steel panels after immersion in ADTP extracts for 69 h, and revealed that many slices were formed on the surface. The slices were attributed to the formation of Fe2P3O10. Inter-slice gaps may be the reason for the lower corrosion resistance of ADTP compared with the resistance of some toxic pigments containing lead and chromium. Overall, high doses of gamma irradiation improved the corrosion resistance of ADTP.

Preliminary results of sintilimab plus different dose of IBI305 (anti-VEGF monoclonal antibody) in patients with advanced hepatocellular carcinoma: A phase Ib study.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 3079-3079 ◽  
Author(s):  
Wen Zhang ◽  
Xinyu Bi ◽  
Yongkun Sun ◽  
Yue Yu ◽  
Jian-guo Zhou ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Dose Group ◽  
Low Dose ◽  
Objective Response ◽  
High Dose Group ◽  
High Dose ◽  
Advanced Hepatocellular Carcinoma ◽  
Dose Selection ◽  
Anti Vegf ◽  
Treatment Naïve

3079 Background: The study aimed to evaluate the safety and efficacy of sintilimab, a PD-1 blockade, plus IBI305, a biosimilar candidate of bevacizumab, in patients (pts) with advanced hepatocellular carcinoma (HCC). Methods: Adults with histocytologically confirmed advanced or metastatic HCC were enrolled in this two-part study. Part 1 was dose escalation trial, with initial dose of sintilimab 200 mg plus IBI305 7.5 mg/kg, q3w (low-dose group). If tolerable, IBI305 was escalated to 15 mg/kg (high-dose group). In part 2 for extension, at least 20 pts were enrolled to each tolerable dose group. Results: As data cutoff (Jan. 7, 2020), 50 pts were enrolled, 29 in low-dose group and 21 in high-dose group. 41 patients were systemic treatment naïve. The median treatment cycle was 4 (range: 1-19) in low-dose group and 11 (range: 1-16) in high-dose group. Most TRAEs were G1-2 with the most common being hypertension (28.0%) and pyrexia (26.0%). Totally, the grade 3 or more TRAEs were occurred in 6 (12.0%) pts, including hypertension occurred in 2 (4%) pts. The objective response rate (ORR) per RECIST v1.1 was 24.1% (95%CI: 10.3 - 43.5) in low-dose group, and 33.3% (95% CI:13.3 - 59.0) in high-dose group. As with the cutoff date, the median PFS has not been reached and the 6-month PFS rates were 60.5% (95%CI 36.1, 78.0) and 75.8% (95% CI: 47.3, 90.2), respectively. Conclusions: The combination of sintilimab and IBI305 showed promising efficacy and favourable safety profile in advanced HCC in both low-dose and high-dose groups. The preliminary result of this study warrant further exploration of dose selection for anti-VEGF/VEGFR agent when combined with PD-1/PD-L1 antibody. Clinical trial information: NCT04072679 . [Table: see text]

scholarly journals Acute Administration of Caffeine: The Effect on Motor Coordination, Higher Brain Cognitive Functions, and the Social Behavior of BLC57 Mice

2018 ◽  
Vol 8 (8) ◽  
pp. 65 ◽  
Author(s):  
Sayed Almosawi ◽  
Hasan Baksh ◽  
Abdulrahman Qareeballa ◽  
Faisal Falamarzi ◽  
Bano Alsaleh ◽  
...  
Keyword(s):  
Social Behavior ◽  
Dose Group ◽  
Motor Coordination ◽  
Control Group ◽  
High Dose ◽  
Moderate Dose ◽  
Caffeine Consumption ◽  
Brain Functions ◽  
The Social ◽  
High Doses

Excessive caffeine consumption causes adverse health effects. The effects of moderate and high doses of caffeine consumption on the motor coordination, cognitive brain functions, and the social behavior in mice were studied. Animals were divided into three groups: control group, moderate dose group (Ac MD), and high dose group (Ac HD). The animals were tested after 7 days of caffeine administration. A rotarod test for motor coordination showed that the mice of the moderate dose group could stay on the rotating rod longer before falling in comparison to the control group and the high dose group. A water maze test for learning and memory showed better performance of mice receiving the moderate dose of caffeine compared to the other groups. Animals that were administered moderate as well as high doses of caffeine showed no sociability and no preference for social novelty in the three-chamber test used to test social behavior. In an elevated plus maze test, control animals showed no anxiety-like behavior while mice from both of the groups administered with caffeine showed anxiety-like behaviors. Our data conclude that the effects of caffeine on higher brain functions depend on the administration dose. When caffeine was given in moderate doses, it resulted in enhancement of memory and motor coordination functions. However, high doses caused defects in memory and learning. The social behavior of the mice, as determined by the level of anxiety and sociability, was affected negatively by moderate as well as high dose caffeine administration.

scholarly journals Acute Administration of Caffeine: The Effect on Motor Coordination, Higher Brain Cognitive Functions and the Social Behavior of BLC57 Mice

2018 ◽  
Author(s):  
Sayed Almosawi ◽  
Hasan Baksh ◽  
Abdulrahman Qareeballah ◽  
Faisal Falamarzi ◽  
Bano Alsaleh ◽  
...  
Keyword(s):  
Social Behavior ◽  
Learning And Memory ◽  
Dose Group ◽  
Motor Coordination ◽  
Control Group ◽  
High Dose ◽  
Acute Administration ◽  
Moderate Dose ◽  
The Social ◽  
High Doses

Heavy caffeine consumption is associated with adverse health effects. The effects of moderate and high doses of caffeine mixed with drinking water on the motor coordination, learning and memory and the social behavior in mice were studied in mice. Animals were divided into 3 groups: control group, moderate dose group (Ac MD) and high dose group (Ac HD). The animals were tested after 7 days of caffeine administration. Rota rod test for motor coordination showed that the mice of the moderate dose group could stay more time on the rotating rod before they fall than the control group and the high dose group. Water maze test for learning and memory showed better performance of mice receiving moderate dose of caffeine compared to the other groups. Animals that were administered moderate as well as high doses of caffeine showed no sociability and no preference for social novelty in the three-chamber test used to test the social behavior. In elevated plus maze, control animals showed no anxiety- like behavior while mice administered with caffeine were both showing anxiety-like behaviors. We concluded that acute administration of moderate dose of caffeine to mice could enhance their spatial memory and motor coordination. High doses however caused defects in memory and learning. The social behavior as the level of anxiety and sociability was affected negatively by moderate as well as high dose caffeine administration.

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