Intrathecal methotrexate in children with leukemia is known to cause seizures, dementia, leukoencephalo pathy, and cognitive dysfunction after long-term treatment. To investigate the cognitive dysfunction, male Wistar rats were given multiple intracerebroventricular injections of methotrexate. Its effect on behaviour was tested in the two-compartment conditioned avoidance task and dark–bright arena test. Levels of brain amines in the hippocampal region of the brain were estimated by HPLC. The qualitative and quantitative histopathological changes in the different regions of the hippocampus were studied by cresyl violet staining. Multiple injections (1 or 2 mg/kg) produced convulsions and learning and memory impairment but did not induce anxiolytic activity. They also reduced concentrations of all three brain amines (norepinephrine, dopamine, and serotonin) and the serotonin metabolite 5-hydroxyindoleacetic acid. The CA4 region of the hippocampus was severely affected by intraventricular methotrexate. Disruption of brain monoamines has been proposed as a cause of brain dysfunction from this chemotherapy, and that disruption may in turn involve cytotoxic effects of methotrexate on brain tissue. The outcomes of this study may have therapeutic implications in the management of cancer conditions, particularly in childhood lymphoblastic leukemia.Key words: methotrexate, hippocampus, norepinephrine, dopamine, serotonin, learning and memory.

Alzheimer’s disease (AD) is characterized by the accumulation of neurofibrillary tangles (NFT), deposition of beta amyloid plaques, and consequent neuronal loss in the brain tissue. Oxidative stress to the neurons is often attributed to AD, but its link to NFT and β-amyloid protein (BAP) still remains unclear. In an animal model of AD, we boosted the oxidative defense by N-Acetyl cysteine (NAC), a precursor of glutathione, a powerful antioxidant and free radical scavenger, to understand the link between oxidative stress and NFT. In mimicking AD, intracerebroventricular (ICV) colchicine, a microtubule disrupting agent also known to cause oxidative stress was administered to the rats. The animal groups consisted of an age-matched control, sham operated, AD, and NAC treated in AD models of rats. Cognitive function was evaluated in a passive avoidance test; neuronal degeneration was quantified using Nissl staining. NFT in the form of abnormal tau expression in different regions of the brain were evaluated through immunohistochemistry using rabbit anti-tau antibody. ICV has resulted in significant cognitive and neuronal loss in medial prefrontal cortex (MFC) and all the regions of the hippocampus. It has also resulted in increased accumulation of intraneuronal tau in the hippocampus and MFC. NAC treatment in AD model rats has reversed the cognitive loss and neuronal degeneration. The intraneuronal tau expression also minimized with NAC treatment in AD model rats. Thus, our findings suggest that an antioxidant supplement during the progression of AD is likely to prevent neuronal degeneration by minimizing the neurofibrillary degeneration in the form of tau accumulation.

Among the many factors responsible for the cognitive decline in Alzheimer’s disease, beta amyloid protein and plaque formation is crucial. This amyloid pathology is associated with activation of glial cells and oxidative stress but whether oxidative stress activates beta amyloid protein in the neurons is not clear. Further the expression of microglia is also known to vary during pathogenesis of beta amyloid plaques. The aim of the present study is to evaluate the antioxidant effect of NAC on amyloid pathology and cognition and also to investigate the link between amyloid pathology and glial cells activation. Intracerebroventricular colchicine in rats known mimics human AD in many aspects including memory loss, oxidative stress, and hyper phosphorylation of tau protein. The animal groups consisted of age matched control, sham operated, AD, and NAC treated in AD models of rats. Cognitive function was evaluated in active avoidance test; beta amyloid protein, beta amyloid plaques, astrocytes, and microglia cells were quantified using immunohistochemistry in hippocampal and prefrontal cortices. Colchicine has resulted in significant cognitive loss, increased intraneuronal beta amyloid protein expression, increased reactive astrocytes, and activated microglia in all the regions of the hippocampus and prefrontal cortices. The antioxidant NAC has reversed the cognitive deficits and inhibited microglia activation but failed to inhibit BAP expression and astrocytosis. Intraneuronal BAP accumulation is deleterious and known to adversely affect cognition, but in this study in spite of intraneuronal BAP accumulation, the cognition is restored. It can be postulated that NAC might have reversed the effect of intraneuronal beta amyloid protein by acting on some downstream compensatory mechanisms which needs to be explored.

Prenatal stress-induced neurobehavioral deficits observed in offspring are multifactorial, including oxidative stress in the developing brain. The time by which the developing brain acquires self-defense against oxidative stress is not clear. Hence in the present study we aimed to evaluate the...

Prenatal adversaries like stress are known to harm the progeny and oxidative stress, which is known to be one of the causative factors. N-acetyl cysteine (NAC), which is a potent antioxidant, has been shown to play a neuroprotective role in humans and experimental animals. This study examines the benefits of NAC on the prenatal stress-induced learning and memory deficits and alteration in brain neurotransmitter in rat pups. Pregnant dams were restrained (45 min; 3 times/day) during the early or late gestational period. Other groups received early or late gestational restrain stress combined with NAC treatment throughout the gestational period. At postnatal day (PND) 28, offspring were tested in a shuttle box for assessing learning and memory, which was followed by a brain neurotransmitter (dopamine, norepinephrine, and serotonin) estimation on PND 36. Late gestational stress resulted in learning deficits, the inability to retain the memory, and reduced brain dopamine content while not affecting norepinephrine and serotonin. NAC treatment in prenatally stressed rats reversed learning and memory deficits as well as brain dopamine content in offspring. These findings suggest that NAC protect the progeny from an undesirable cognitive sequel associated with prenatal stress.

The COVID-19 pandemic worldwide forced governments to undertake intervention measures to encourage social distancing. Meanwhile, traumatic skin lacerations require multiple hospital visits for dressing changing and suture removal since they are usually repaired with non-absorbable sutures. These visits can be avoided by using absorbable sutures instead. However, absorbable sutures carry the “potential” risk of wound infection. In the current study, our first objective was to determine the non-inferiority of absorbable sutures regarding infection rate after repairing traumatic wound lacerations in comparison to the conventional non-absorbable ones. Our second objective was to evaluate the superiority of absorbable sutures in regard to postoperative clinic visits for suture removal and wound dressing compared to the non-absorbable ones. A sample of 471 patients with traumatic skin lacerations was analyzed during the COVID-19 pandemic in April 2020. In the control group, wounds were repaired using non-absorbable sutures, while rapid-onset absorbable sutures were used in the treatment group. By conducting a phone/video call follow-up after 21 days, several parameters regarding infection signs and clinic visits were compared between both groups. A significant decrease in total trauma patients (45.4%) and those who required suturing (51.2%) was observed in April 2020 compared to the same month of the previous four years (p = 0.001 (2016), p = 0.027 (2017), p = 0.027 (2018), and p = 0.001 (2019)). Regarding wound infection, no statistically significant difference (p = 0.623) was observed between the absorbable (3.2%) and non-absorbable (4.9%) groups. Using absorbable sutures resulted in significantly (p < 0.001) fewer postoperative hospital visits compared to using non-absorbable sutures (mean: one versus three visits). Using absorbable sutures to repair traumatic wound lacerations is safe regarding wound healing and infection rates. They also reduce postoperative hospital visits since they are not intended to be removed. Therefore, they should be considered during a pandemic to reduce hospital visits for suture removal, which will subsequently enhance social distancing and relieve hospital load.