35 research outputs found
Predictors of smoking lapse in a human laboratory paradigm
During a smoking quit attempt, a single smoking lapse is highly predictive of future relapse. While several risk factors for a smoking lapse have been identified during clinical trials, a laboratory model of lapse was until recently unavailable and, therefore, it is unclear whether these characteristics also convey risk for lapse in a laboratory environment.The primary study goal was to examine whether real-world risk factors of lapse are also predictive of smoking behavior in a laboratory model of smoking lapse.After overnight abstinence, 77 smokers completed the McKee smoking lapse task, in which they were presented with the choice of smoking or delaying in exchange for monetary reinforcement. Primary outcome measures were the latency to initiate smoking behavior and the number of cigarettes smoked during the lapse. Several baseline measures of smoking behavior, mood, and individual traits were examined as predictive factors.Craving to relieve the discomfort of withdrawal, withdrawal severity, and tension level were negatively predictive of latency to smoke. In contrast, average number of cigarettes smoked per day, withdrawal severity, level of nicotine dependence, craving for the positive effects of smoking, and craving to relieve the discomfort of withdrawal were positively predictive of number of cigarettes smoked.The results suggest that real-world risk factors for smoking lapse are also predictive of smoking behavior in a laboratory model of lapse. Future studies using the McKee lapse task should account for between subject differences in the unique factors that independently predict each outcome measure
Evaluation of Fetal Toxicity of HESA-A, a Natural Anticancer Agent, in Mice
Abstract:
Introduction: HESA-A is an active natural compound with herbal and marine origin. It contains inorganic, organic and aqueous fractions, and has shown antioxidant, cytotoxic and anticancer effects. In this study, the teratogenic effects of HESA-A in mice have been evaluated.
Methods: Several doses of HESA-A were administered orally to pregnant mice on days 6 to 14 of gestation. Various parameters in pregnant mice and embryos during and after pregnancy were evaluated and recorded. At the end of pregnancy, embryos were sectioned out and studied for external morphological abnormalities and by specific skeletal staining for skeletal malformations.
Results: Weight gain of pregnant mice showed that only the highest dose (800 mg/kg) caused gain retardation. Also, only the highest dose led to reduction of uterus weight, number of viable embryos, and weight and crown-lump length of embryos. Increase in fetal resorption by the highest dose of HESA-A was another important observation. Low and medium doses of HESA-A did not cause any significant external or skeletal abnormalities. However, higher doses caused embryo malformations such as short limbs, spinal abnormalities, dermal cysts, microphtalmia, and cleft palate.
Conclusion: According to this study, only high doses of HESA-A, which are many times higher than the usual therapeutic doses, may cause embryonic toxicity. Mechanisms of these abnormalities are not clear and need to be determined.
Keywords: HESA-A, Embryotoxicity, Mic
Effects of Ethylene Glycol Monomethyl Ether and Its Metabolite, 2‐Methoxyacetic Acid, on Organogenesis Stage Mouse Limbs In Vitro
Effect of carbamazepine on homocysteine serum level in pregnant mice and fetal malformations outcome
Background and Objective: Carbamazepine during pregnancy can induce various malformations. Recent studies have showed an increase in homocysteine level due to Carbamazepine administration. This study was to evaluate the effect of Carbamazepine on homocysteine serum level in pregnant mice and fetal malformations outcome. Materials and Methods: In this experimental study, 40 BALB/c timed-pregnant mice were allocated into 2 experimental and 2 control groups. The experimental groups were received daily intraperitoneal injections of 30 mg/kg (group I) or 60 mg/kg (group II) of Carbamazepine on gestational days 6 to 15. The control groups were received either - normal saline or Tween 20. Dams underwent Cesarean section on GD 18. External examinations were done and all data concerning malformations, weight and crown-rump of fetuses collected. Blood samples were collected from Dams' hearts prior to performing the Cesarean section. Homocysteine was measured using ELISA method. Data were analyzed using SPSS-18, ANOVA, Chi-Square and Tukey tests. Results: Significant increase in Homocysteine levels of dams’ serum compared to control groups was seen in both experimental groups I and II (10.56±1.31 and 11.11±1.64 µmol/L, respectively, P<0.05). The mean weight and crown-rump of the fetuses in both experimental groups were significantly reduced compared with those of the control groups (P<0.05). Various malformations such as limb defects, vertebral defects, facial deformity and severe malformations were observed in fetuses of both experimental groups. Conclusion: Serum elevation of homocysteine in Carbamazepine exposed pregnant mice may be a risk factor for induction of fetal malformations
Effect of potassium benzoate on BALB/c mice placenta: a histopathological study
Background and Objective: The food additives, like sodium and potassium benzoate are used in many food products and drugs to prevent the growth of yeast and molds. There is no report about the histopathological effect of potassium benzoate. Placenta, has a critical role in embryonic development therefore this study was set up to evaluate the effects of potassium benzoate on placenta of BALB/c mice.
Materials and Methods: 45 BALB/c female mice were allocated into two experimental (1, 2) and one control groups. Experimental groups received daily intraperitoneal injection of 280 and 560 mg/kg/body weight of potassium benzoate and control group received normal saline. All injections were done during 10 days before mating and 5th to 16th of gestational days (GD). In GD 18 all placenta were removed via cesarean section. Macroscopic studies for morphological abnormalities were done and after measuring of placental weight and diameter, for microscopic studies the specimens were fixed and tissue passage were done. Tissue sections were stained with hematoxylin-eosin and histopathological changes were studied. Weight, diameter and percentage of agenesis of placenta in all groups were gathered. Data analyzed with using
SPSS-11.5, ANOVA and Tukey tests.
Results: The mean weight and diameter of the placenta in both experimental groups 1 and 2 were significantly decreased compared to control group. Also atrophy of placenta in the experimental groups was increased significantly compared to the control group (P<0.05). Comparison of weight and diameter between groups 1 and 2 was not significant. Percentage of placenta agenesis in the experimental groups was increased significantly compared to the control group (P<0.05). Massive hemorrhage in labyrinth zone, fetal and maternal zones were seen in both experimental groups.
Conclusion: This study showed that exposure of potassium benzoate during mice pregnancy cause morphological and histopathological changes of placenta, including decrease of weight and diameter, agenesis, hemorrhage and tissue disorders
The protective role of folic acid on tratogenic effect of Carbamazepine in Balb/c mice
Background and Objective: Carbamazepine (CBZ) is an antiepileptic drug that causes significant malformations such as neural tube defects (NTDs), cardiac, skeletal and craniofacial defects if it is consumed during pregnancy. The aim of this study was to evaluate the protective effect of folic acid on prevention of birth defect due to Carbamazepine in Balb/c mice. Materials and Methods: In this experimental study, Sixty Balb/c timed-pregnant mice were divided into 4 experimental and 2 control groups. Two experimental groups received daily intraperitoneal injections of 30 mg/kg (group I) and 60 mg/kg/body weight (group II) of CBZ on gestational days (GD) 6 to 15. Two other experimental groups (group III and IV) received similar doses of CBZ with folic acid supplement (3 mg/kg/day) by gavages route for 10 days before pregnancy and 15 days after GD0 (gestational day 0). Two control groups received normal saline or Tween 20 (polysorbate 20). Dams underwent cesarean section on GD18 and embryos were collected. External examination was done and data concerning malformations, weight and crown- rump of fetuses were collected and analyzed by using SPSS-11.5 software and ANOVA and chi-square tests. Results: The mean weight and crown-rump of the fetuses in both experimental groups I and II were significantly reduced. Also in both experimental groups I and II various malformations were detected such as open eyes, limb defects, scoliosis, facial deformity and NTDs. The mean weight and crown-rump of fetuses in the folic acid treated groups did not show any meaningful differences in comparison with fetuses in experimental groups I and II. Also, meaningful reductions in eye, vertebral, limb and facial defects were seen in fetuses of group III. In experimental group IV, reduction of vertebral and limb defects were observed. Conclusion: This study showed that consumption of folic acid (3 mg/kg/body weight) before and during pregnancy can reduce birth defects due to CBZ in Balb/c mice fetus