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Screening Smokes: Applications, Toxicology, Clinical Considerations, and Medical Management *
Published in Brian J. Lukey, James A. Romano, Salem Harry, Chemical Warfare Agents, 2019
Lawrence A. Bickford, Harry Salem
Subchronic repeated exposure studies were also conducted by Callahan et al. (1986), who exposed mice and rats to DF2 smoke at a mean concentration of 2300 mg m−3 for 15 or 60 min each day for 5 days week−1 for up to 13 weeks. The only clinical sign was hypoactivity. Mild-to-moderate pulmonary congestion was seen compared with unexposed controls, with minimal inflammatory changes in the nasal turbinates and trachea. Lock et al. (1984) conducted a 13 week study in which male and female rats were exposed to diesel-fuel smoke for 4 h twice a week for 13 weeks. Exposure concentrations were measured as 170, 870, and 1600 mg m−3. There were no signs and no mortality. Body weight decreased until the fourth exposure week, after which there were body weight gains. Breathing rates and CO diffusing capacity were not affected, but residual volume was significantly reduced with the highest–exposure concentration group. Functional residual capacity, vital capacity, and peak flow rate were not affected. No microscopic pathology was seen.
Clinical Theory and Skills EMIs
Published in Michael Reilly, Bangaru Raju, Extended Matching Items for the MRCPsych Part 1, 2018
Cerebrovascular disease.Cholinergic hypoactivity.Cholinergic hyperactivity.Dopamine hyperactivity.Excessive alcohol use.Immediate and short-term memory.Immediate, short-term and long-term memory.Intoxication due to prescribed medication.Nocturnal arousal and daytime drowsiness.Nocturnal drowsiness and daytime arousal.
Intracellular Signaling Transduction Dysregulation in Depression and Possible Future Targets for Antidepressant Therapy:Beyond the Serotonin Hypothesis
Published in Siegfried Kasper, Johan A. den Boer, J. M. Ad Sitsen, Handbook of Depression and Anxiety, 2003
Andrea Trentani, S. Kuipers, G.J. Ter Horst
At this point there are two possibilities. Prolonged and persistent stress is a cause of neuronal hyperactivity associated with massive release, and eventually exhaustion of BDNF supplies. This leads to a stress-induced deficiency of BDNF and reduction of neuronal plasticity.Sustained stress gradually increases the activity of specific limbic areas and leads to their hyperactivity (earlier in females because of the higher basal activity closer to the overload threshold). Prolonged neuronal hyperactivity causes the exhaustion of the brain region and, consequently, hypoactivity (overload). At this point, the brain region, because of the reduction of BDNF synthesis and release (BDNF release is reported to be activity-dependent), is unable to face the effects of stress with the plastic changes that it needs. Thus, reduction of BDNF availability might increase the vulnerability of the brain to subsequent insults and may be the prelude to selective limbic defects because of the brain’s inability to deal with the effects of stress with an adequate structural plasticity.
Differences between adult and adolescent male mice in approach/avoidance and expression of hippocampal NPY in response to acute footshock
Published in Stress, 2021
Mariana A. Cortes, Katelynn M. Corder, Lynn E. Dobrunz
Avoidance of situational reminders of traumatic experience is a core feature of PTSD (Substance Abuse and Mental Health Services Administration n.d.). Importantly, while adult footshock mice showed both increased avoidance on the EPM and hypolocomotion, adolescent footshock mice showed only hypolocomotion. The hypolocomotion was a robust effect of footshock in both age groups, as it was observed on both the EPM and the OF. Our results are in agreement with others that have demonstrated that footshock exposure causes immobility in young adult and adult rodents (Stam, 2007). Since we did not identify a deficit in motor function on the rotarod (Curzon et al., 2009), we interpret this hypoactive behavior as a generalized freezing response due to the traumatic nature of the footshock protocol. However, it is possible that impairments would be evident at the one week time point, contributing to the observed hypoactivity. While trauma-induced immobility occurs in both age groups, our results show that heightened avoidance behavior is a feature observed only in the adult group, indicating that this effect is age dependent. Together, these findings support the idea that in adult rodents, acute traumatic experiences result in lasting defensive behaviors, as previously observed (Li et al., 2017; Louvart et al., 2005).
Evaluation of acute and subacute toxicity of sodium taurodeoxycholate in rats
Published in Drug and Chemical Toxicology, 2021
Hyung Jun Choi, Jun-Won Yun, Youn-Hee Kim, Euna Kwon, Min-Kyong Hyon, Ji Young Kim, Jeong-Hwan Che, Woo Ho Kim, Seung-Yong Seong, Byeong-Cheol Kang
In order to determine the approximate median lethal dose and optimal dose ranges for the 4-week repeated-dose toxicity study, acute toxicity was evaluated after i.v. infusion of TDCA into lateral tail vein of SD rats. In the first sighting study, the i.v. infusion of 300 mg/kg TDCA in a male rat resulted in dark discoloration of the tail on day 1 and subsequent partial loss of tail on day 7 (Table 1). The hypoactivity was observed in a female rat after i.v. infusion of 300 mg/kg TDCA. The female rat died of possible liver toxicity with signs of jaundice (yellowish fat and skin) on day 2. In the second sighting study, dark discoloration at the injection site of tail was observed on day 1 when infused with 150 mg/kg TDCA (Table 1). However, there was no significant change in mortality, clinical signs, and necropsy findings in either male or female rats following infusion with 50 mg/kg TDCA. Taken together, i.v. infusion of 50 mg/kg TDCA showed no significant toxicity macroscopically.
Effect of curcumin nanoparticles on the cisplatin-induced neurotoxicity in rat
Published in Drug and Chemical Toxicology, 2019
Yasser A. Khadrawy, Mayada M. El-Gizawy, Safwa M. Sorour, Hussein G. Sawie, Eman N. Hosny
The behavioral data demonstrate that CP reduces the motor activity of rats as indicated from the significant increase in the time elapsed in the central square and freezing time and the significant decrease in number of crossed lines and number of rearings. Our results are in parallel with the findings of Ali et al. (2014) who reported that CP treatment significantly decreased motor and exploratory activities, and increased immobility time in depression models, suggesting a possible depressive-like state. More recently, Abdelkader et al. (2017) have shown that CP increased immobility time and reduced the number of crossed squares and number of rearings. They attributed the decrease in motor activity to the depressive-like symptoms induced by CP. These data are in harmony with previous studies that showed that CP administration impaired explorative behaviors, memory retention, and locomotor activity in rats (Golchin et al. 2015). Therefore, the hypoactivity induced by CP in the present study may reflect the development of depressive symptoms.