More than a small adult brain: Lessons from chemotherapy-induced cognitive impairment for modelling paediatric brain disorders.

Childhood is recognised as a period of immense physical and emotional development, and this, in part, is driven by underlying neurophysiological transformations. These neurodevelopmental processes are unique to the paediatric brain and are facilitated by augmented rates of neuroplasticity and expanded neural stem cell populations within neurogenic niches. However, given the immaturity of the developing central nervous system, innate protective mechanisms such as neuroimmune and antioxidant responses are functionally naïve which results in periods of heightened sensitivity to neurotoxic insult. This is highly relevant in the context of paediatric cancer, and in particular, the neurocognitive symptoms associated with treatment, such as surgery, radio- and chemotherapy. The vulnerability of the developing brain may increase susceptibility to damage and persistent symptomology, aligning with reports of more severe neurocognitive dysfunction in children compared to adults. It is therefore surprising, given this intensified neurocognitive burden, that most of the pre-clinical, mechanistic research focuses exclusively on adult populations and extrapolates findings to paediatric cohorts. Given this dearth of age-specific research, throughout this review we will draw comparisons with neurodevelopmental disorders which share comparable pathways to cancer treatment related side-effects. Furthermore, we will examine the unique nuances of the paediatric brain along with the somatic systems which influence neurological function. In doing so, we will highlight the importance of developing in vitro and in vivo paediatric disease models to produce age-specific discovery and clinically translatable research.

[Refusal of care by the elderly]. / Le refus de soins en gériatrie.

Refusal of care is a frequent occurrence in geriatric medicine, especially among people with neurocognitive diseases, particularly in the advanced stages. These refusals of care are a daily burden, not only for the patients themselves, but also for their carers and caregivers. Although they can be prevented, the absence of a single, simple strategy for overcoming them is a real challenge for professionals and carers alike. Their management calls for an approach that is essentially non-pharmacological, always interdisciplinary, humanistic and ethically grounded.

Sex, sepsis and the brain: defining the role of sexual dimorphism on neurocognitive outcomes after infection.

Sexual dimorphisms exist in multiple domains, from learning and memory to neurocognitive disease, and even in the immune system. Male sex has been associated with increased susceptibility to infection, as well as increased risk of adverse outcomes. Sepsis remains a major source of morbidity and mortality globally, and over half of septic patients admitted to intensive care are believed to suffer some degree of sepsis-associated encephalopathy (SAE). In the short term, SAE is associated with an increased risk of in-hospital mortality, and in the long term, has the potential for significant impairment of cognition, memory, and acceleration of neurocognitive disease. Despite increasing information regarding sexual dimorphism in neurologic and immunologic systems, research into these dimorphisms in sepsis-associated encephalopathy remains critically understudied. In this narrative review, we discuss how sex has been associated with brain morphology, chemistry, and disease, sexual dimorphism in immunity, and existing research into the effects of sex on SAE.

The effect of antiretroviral therapy with high central nervous system penetration on HIV-related cognitive impairment: a systematic review and meta-analysis.

Chronic complications are a significant concern for people living with HIV/AIDS (PLWHA) infection. HIV-associated neurocognitive disorders (HAND) are prevalent in PLWHA. Yet, the efficacy of medications that penetrate the central nervous system (CNS) at preventing or slowing the progression of HAND remains largely unknown. The objective of this study was to determine whether high CNS penetration effectiveness (CPE) regimens improve neurocognitive test scores in PLWHA on combined antiretroviral therapy (cART). Primary literature evaluating cognitive outcomes based on CPE score of cART regimens in PLWHA was assembled from PubMed/Medline and EMBASE. Both randomized controlled trials and observational studies with at least 12 weeks of follow-up were included. A meta-analysis was conducted to calculate the standardized mean difference. Eight trials including a total of 3,303 patients with 13,103 person-years of follow-up were included in the systematic review. Four trials (n = 366 patients) met our inclusion criteria and were included in the meta-analysis. In the meta-analysis, HIV regimens with a high CPE score did not affect NPZ-4 or GDS scores (standardized mean difference (SMD) 0.10, 95% CI -0.19, 0.38; I2 = 26%). Future studies with larger sample sizes are warranted to prospectively evaluate the relationship between CPE and progression of HAND.

Dopamine increases HIV entry into macrophages by increasing calcium release via an alternative signaling pathway.

Dopaminergic dysfunction has long been connected to the development of HIV infection in the CNS. Our previous data showed that dopamine increases HIV infection in human macrophages by increasing the susceptibility of primary human macrophages to HIV entry through stimulation of both D1-like and D2-like receptors. These data suggest that, in macrophages, both dopamine receptor subtypes may act through a common signaling mechanism. To define better the mechanism(s) underlying this effect, this study examines the specific signaling processes activated by dopamine in primary human monocyte-derived macrophages (hMDM). In addition to confirming that the increase in entry is unique to dopamine, these studies show that dopamine increases HIV entry through a PKA insensitive, Ca2+ dependent pathway. Further examination demonstrated that dopamine can signal through a previously defined, non-canonical pathway in human macrophages. This pathway involves both Ca2+ release and PKC phosphorylation, and these data show that dopamine mediates both of these effects and that both were partially inhibited by the Gq/11 specific inhibitor YM-254890. Studies have shown that Gq/11 preferentially couples to the D1-like receptor D5, indicating an important role of the D1-like receptors in mediating these effects. These data indicate a role for Ca2+ flux in the HIV entry process, and suggest a distinct signaling mechanism mediating some of the effects of dopamine in macrophages. Together, the data indicate that targeting this alternative dopamine signaling pathway might provide new therapeutic options for individuals with elevated CNS dopamine suffering from NeuroHIV.

The potential of transcranial magnetic stimulation for population-based application: a region-based illustrated brief overview.

The awareness of the global trends in neuroscience study, especially in the cognitive neuroscience field, should be increased. One notable approach is the use of transcranial magnetic stimulation (TMS) not only as a research tool but also as a choice for treatment and rehabilitation in neurological disorders, such as post-stroke hemiplegia, visuospatial neglect syndrome, Alzheimer's disease (AD) and psychiatric conditions such as major depression and schizophrenia. All of these occur in significant numbers in highly populated regions. This paper briefly discusses the basic protocols and potential benefits of using TMS with the aim of providing insight that is useful in the design of future public health strategies in highly populated regions with a large neurocognitive burden of disease where this technique is currently underemployed.

Microbiota and cognitive impairment: Current challenges and future perspectives.

Recent studies indicate that gut microbiota may play a crucial role in cognitive function. Individuals with cognitive impairment tend to have fewer beneficial gut bacteria and lower microbial diversity. Therefore, gut microbiota could be a potential biomarker for cognitive vulnerability. Further research is needed to understand the mechanisms and lifestyle factors affecting both microbiota composition and cognitive health. While the direct impact of microbiota and diet on cognitive impairment remains unconfirmed, this area holds promise for developing new preventive and treatment strategies.

The Influence of Covid-19 Infection on Neurocognitive Disorders.

Neurocognitive disorders are a group of disorders characterized by an impaired cognition which has not been present since birth or very early life and represents a decline from a previous attained level of functioning. The case we studied is M.E., a 62 years female, married, from rural area, working as a tailor, without any psychiatric history. She develops psychiatric symptoms during Covid-19 infection and treatment, in November 2020. The patient has been admitted in psychiatric care, in that time, for about one month, for a persistent confusion state during and after this event. These symptoms diminish the patient's level of functioning and seemed to be related with the Covid-19 infection or treatment. Psychological investigation underlines a MMSE 14, severe impairment in attention, short-term and long-term memory. CT evaluation presents normal relation except a moderate general atrophy, according with patient's age. Differential diagnosis will be discussed. The treatment has proven its effectiveness, the patient regaining her ability to orientate, could do housework, good improvement in attention and short-term memory. We emphasize that there is correlation between the Covid-19 infection and confusive state and delirium in patients, as a comorbidity, followed in many cases by chronic progressive neurocognitive disorder, especially in elderly.

Ulinastatin attenuates isoflurane-induced cognitive dysfunction in aged rats by inhibiting neuroinflammation and ß-amyloid peptide expression in the brain.

Objective: Postoperative neurocognitive disease (PNCD) in the aged is a major clinical problem with unclear mechanisms. This study was designed to explore the mechanisms for ulinastatin (UTI) to attenuate isoflurane-induced cognitive decline in Fischer-344 rats. Methods: The rats were divided into four groups: Control (0.9% saline only), Isoflurane (exposure to 1.2% isoflurane), Isoflurane-plus-UTI (exposure to 1.2% isoflurane followed by 100,000 U/kg UTI injection i.v.) and UTI-plus-isoflurane (i.v. of 100,000 U/kg UTI followed by 1.2% isoflurane exposure). After respective tests, the concentrations of tumour necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) in the brain were determined by ELISA the expression of ß-amyloid peptide (Aß) and cleaved caspase-3 were measured by Western blot. Ratio of apoptotic cells after Barnes maze challenge was assessed by TUNEL assay. Results: In both Barnes Maze training and challenge, results indicated isoflurane-impaired learning capacity, while pre-and post-treatment with UTI could attenuate this phenomenon. The ratio of apoptotic cells and the expression of cleaved caspase-3 were increased after isoflurane exposure, indicating that isoflurane could induce neuronal apoptosis, while both pre- and post-treatment with UTI could diminish these effects. Moreover, UTI inhibited the expression of TNF-α, IL-1ß and Aß induced by isoflurane in rat brain harvested at 16 h after isoflurane exposure. Conclusion: These results suggest that UTI inhibits neuronal apoptosis in rat brain by attenuating increased expression of Aß42 and inflammatory cytokines, which may contribute to its alleviation of isoflurane-induced cognitive dysfunction in rats. Moreover, UTI pre-treatment before isoflurane exposure showed more effective than post-treatment.

The Role of Nuclear Medicine in the Staging and Management of Human Immune Deficiency Virus Infection and Associated Diseases.

Human immune deficiency virus (HIV) is a leading cause of death. It attacks the immune system, thereby rendering the infected host susceptible to many HIV-associated infections, malignancies and neurocognitive disorders. The altered immune system affects the way the human host responds to disease, resulting in atypical presentation of these disorders. This presents a diagnostic challenge and the clinician must use all diagnostic avenues available to diagnose and manage these conditions. The advent of highly active antiretroviral therapy (HAART) has markedly reduced the mortality associated with HIV infection but has also brought in its wake problems associated with adverse effects or drug interaction and may even modulate some of the HIV-associated disorders to the detriment of the infected human host. Nuclear medicine techniques allow non-invasive visualisation of tissues in the body. By using this principle, pathophysiology in the body can be targeted and the treatment of diseases can be monitored. Being a functional imaging modality, it is able to detect diseases at the molecular level, and thus it has increased our understanding of the immunological changes in the infected host at different stages of the HIV infection. It also detects pathological changes much earlier than conventional imaging based on anatomical changes. This is important in the immunocompromised host as in some of the associated disorders a delay in diagnosis may have dire consequences. Nuclear medicine has played a huge role in the management of many HIV-associated disorders in the past and continues to help in the diagnosis, prognosis, staging, monitoring and assessing the response to treatment of many HIV-associated disorders. As our understanding of the molecular basis of disease increases nuclear medicine is poised to play an even greater role. In this review we highlight the functional basis of the clinicopathological correlation of HIV from a metabolic view and discuss how the use of nuclear medicine techniques, with particular emphasis of F-18 fluorodeoxyglucose, may have impact in the setting of HIV. We also provide an overview of the role of nuclear medicine techniques in the management of HIV-associated disorders.

Psychopathological Behaviour and Cognition in Morbid Obesity.

BACKGROUND: Obesity is a chronic condition with high prevalence and multifaceted aetiology, accompanied by an increased risk of morbidity and mortality. Obesity has several negative effects on the psychological status, and the severity of psychological disorders correlates with the degree of obesity. OBJECTIVE: Aim of this review is to provide an overview of the literature concerning the psychological distress associated with severe obesity, which contributes to deterioration of the quality of life of affected patients. METHODS: Dysfunctional eating behaviours and eating disorders, psychiatric comorbidity, cognition and quality of life will be discussed together with the most common drugs that can be employed to treat the various disorders in this peculiar clinical setting. The effects of bariatric surgery will be also reviewed. RESULTS: Obesity is often the result of pathological behaviours implemented in an eating disorder. Inconsistent results have been reported with regard to the effect of severe obesity on cognition, which recognize a multifaceted aetiology. Serotonergic agents play an important role in the management of patients with obesity and binge episodes, fluoxetine being currently a drug approved for this disorder. The efficacy of lorcaserin, a combination of bupropion and naltrexone, or antiepileptic medications (topiramate and zonisamide) has also been proposed. A neuroprotective role of leptin and oestrogen has been hypothesized. Bariatric surgery is a helpful treatment of morbid obese patients, with long-term favourable results on the psychopathological profile. CONCLUSION: Psychological, psychoeducational and psychopharmacological treatment can facilitate weight loss in morbid obese subjects with psychopathological comorbidities. A precise definition of the mechanisms affecting appetite, satiety and energy balance is expected to foster the development of new effective antiobesity drugs.

The Role of Nuclear Medicine in the Staging and Management of Human Immune Deficiency Virus Infection and Associated Diseases / 대한핵의학회잡지

Human immune deficiency virus (HIV) is a leading cause of death. It attacks the immune system, thereby rendering the infected host susceptible to many HIV-associated infections, malignancies and neurocognitive disorders. The altered immune system affects the way the human host responds to disease, resulting in atypical presentation of these disorders. This presents a diagnostic challenge and the clinician must use all diagnostic avenues available to diagnose and manage these conditions. The advent of highly active antiretroviral therapy (HAART) has markedly reduced the mortality associated with HIVinfection but has also brought in its wake problems associated with adverse effects or drug interaction and may even modulate some of the HIV-associated disorders to the detriment of the infected human host. Nuclear medicine techniques allow non-invasive visualisation of tissues in the body. By using this principle, pathophysiology in the body can be targeted and the treatment of diseases can be monitored. Being a functional imaging modality, it is able to detect diseases at the molecular level, and thus it has increased our understanding of the immunological changes in the infected host at different stages of the HIV infection. It also detects pathological changes much earlier than conventional imaging based on anatomical changes. This is important in the immunocompromised host as in some of the associated disorders a delay in diagnosis may have dire consequences. Nuclear medicine has played a huge role in the management of many HIV-associated disorders in the past and continues to help in the diagnosis, prognosis, staging, monitoring and assessing the response to treatment of many HIV-associated disorders. As our understanding of the molecular basis of disease increases nuclear medicine is poised to play an even greater role. In this review we highlight the functional basis of the clinicopathological correlation of HIV from a metabolic view and discuss how the use of nuclear medicine techniques, with particular emphasis of F-18 fluorodeoxyglucose, may have impact in the setting of HIV. We also provide an overview of the role of nuclear medicine techniques in the management of HIV-associated disorders.