Neurosignals最新文献

Hallucination is a sensory perception that occurs in the absence of external stimuli during abnormal neurological disturbances and various mental diseases. Hallucination is recognized as a core psychotic symptom and is particularly more prevalent in individuals with schizophrenia. Strikingly, a significant number of subjects with Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and other neurological diseases like cerebral stroke and epileptic seizure also experience hallucination. While aberrant neurotransmission has been linked to the neuropathogenic events of schizophrenia, the precise cellular mechanism accounting for hallucinations remains obscure. Neurogenesis is a cellular process of producing new neurons from the neural stem cells (NSC)-derived neuroblasts in the brain that contribute to the regulation of pattern separation, mood, olfaction, learning, and memory in adulthood. Impaired neurogenesis in the hippocampus of the adult brain has been linked to stress, anxiety, depression, and dementia. Notably, many neurodegenerative disorders are characterized by the mitotic and functional activation of neuroblasts and cell cycle re-entry of mature neurons leading to a drastic alteration in neurogenic process, known as reactive neuroblastosis. Considering their neurophysiological properties, the abnormal integration of neuroblasts into the existing neural network or withdrawal of their connections can lead to abnormal synaptogenesis, and neurotransmission. Eventually, this would be expected to result in altered perception accounting for hallucination. Thus, this article emphasizes a hypothesis that aberrant neurogenic processes at the level of reactive neuroblastosis could be an underlying mechanism of hallucination in schizophrenia and other neurological diseases.

Retinoblastoma (RB) management has evolved over the last three decades. Goals of modern RB treatment are first to protect life and prevent metastatic disease, then preservation of the globe and useful vision. With modern treatment protocols and early disease detection success rates can reach up to 100% of disease-free-globe and eye preservation. Treatment of advanced cases remains complex, requiring aggressive chemotherapy or/and external beam radiation. Treatment protocols are extremely diverse and dependent on local resources thus success rates are variable. Here we review narratively current treatment protocols and failure rates based on a PubMed search using keywords of retinoblastoma, retinoblastoma seed, retinoblastoma treatment, enucleation.

Malignant tumors of the eyelids and ocular surface are common ocular malignancies. At present, surgical treatment is mostly the first choice for these types of tumors. However, postoperative tumor recurrence and metastasis are still regarded as failures in the treatment of such malignancies. Based on this, malignant tumors of the eyelid and ocular surface are sometimes accompanied by local adjuvant chemotherapy and systemic chemotherapy to treat patients with relapse, invasion of adjacent tissues, and systemic metastases. Still, drug resistance greatly affects the treatment effect. This review lists several mechanisms of recurrence and metastasis of ocular surface and eyelid tumors after surgery, as well as mechanisms that may lead to non-surgical treatment or drug resistance.

The goal of radiotherapy in the treatment of eyelid and ocular surface tumors is to eradicate tumor burden in a manner that maintains visual function and preserve surrounding sensitive ocular tissue. Interventional radiotherapy (IRT-brachytherapy) is a radiotherapy technique associated with a highly focal dose distribution, with the advantage of boosting limited size target volumes to very high dose while sparing normal tissue. The reduction in the ocular and adnexal complications that result from this form of therapy, has led in recent years, to an increase in the use of IRT for the treatment of eyelid and ocular surface tumors. For eyelid malignancies, IRT is used as an independent treatment in small eyelids tumors, in postoperative treatment of high-risk patients and as well as salvage therapy in local recurrences. In the treatment of conjunctival malignancies, due to the high risk of local recurrence, the use of adjuvant therapies as IRT has shown to improve outcomes. In this review, we focus on eyelid and ocular surface IRT techniques and provide an overview of indication, outcomes and toxicity of IRT for the treatment of naïve and recurrent eyelid and conjunctival tumors.

Background/aims: The moust symptoms of piglets infected with Encephalomyocarditis virus (EMCV) are related to breeding difficulty, circulation insufficiency, depression and occurrence of high lethality. An increase of tryptophan metabolism in the periphery and in the central nervous system (CNS) in human and non-human subjects with inflammatory diseases has been suggested. We investigated an alterations of tryptophan metabolite i.e. kynurenic acid (KYNA) level in the serum of piglets after EMC virus infection. In addition, we investigated the markers of immune stimulation i.e. neopterin and β2-microglobulin.

Methods: KYNA was determined by high performance liquid chromatography method, while neopterin and β2-microglobulin by ELISA method. Piglets with an age of 8 weeks were infected intranasal and orally with the EMC virus. Blood samples were collected before virus inoculation at day 0 (control) and at 1, 2, 3 and 4 days post inoculation (DPI) and piglets as control subjects were used, too.

Results: In EMCV infected piglets we observed a time dependent alteration of investigated parameters. KYNA level increased significantly and at 3 DPI was 341% of CO, p<0.001 and at 4 DPI an enhancement was 242% of CO, p<0.001, respectively. Neopterin increased moderately after EMCV infection and at 4 DPI was 130% of CO, p<0.05. Serum β2-microglobulin was slightly lowered and at 4 DPI was 86% of CO, p<0.05. Present data indicate an marked increase of kynurenine metabolism in the periphery after EMCV infection and an moderate activation of immune system.

Conclusion: A marked increase of KYNA and a moderate enhancement of neopterin indicate sensibility of kynurenine metabolism to EMCV infection. Lowering of ß2-microgobulin might relate to development of events leading to the lethality. We suggest that due to viral infection an increase of KYNA might contribute to the inpairment of organs in the periphery and CNS function and might participate by sudden death.

Background/aims: Intravitreal rituximab is an off-label treatment option for primary vitreoretinal lymphoma (PVRL). The objective of this study was to monitor the therapeutic response and safety profile of intravitreal rituximab in a cohort of PVRL patients.

Methods: In this retrospective, uncontrolled, open label, multicentre study, 20 eyes from 15 consecutive patients diagnosed with PRVL received at least one intravitreal injection of 1mg in 0.1ml rituximab. Biodata of the PVRL patients was recorded as well as visual acuity and vitreous haze score immediately before rituximab intravitreal injection and at follow-up examinations. Intravitreal rituximab safety data was also recorded. Additional rituximab injections were made during control visits on a pro re nata (PRN) regime using increased vitreous haze to indicate recurrence.

Results: There was significant vitreous haze reduction (p=0.0002) followed by significant improvement of visual acuity (mean best visual acuity before therapy 0.57 logMAR, after therapy 0.20 logMAR (p=0.0228) during the follow-up time up to 4 years. Only mild ocular side effects were reported. Median follow-up time was 565 days (range, 7-1253 days).

Conclusion: Intravitreal rituximab therapy shows promising PVRL regression without any severe side effects. Although our clinical data support rituximab as intravitreal therapy in PVRL disease, further study is warranted.

The antiaging protein Klotho is encoded by the Klotho gene first identified as an 'aging suppressor', in mice. Klotho deficiency is involved in premature aging and early death, while its overexpression is related to longevity. Klotho is mostly expressed in the kidney, but also in the brain, and in other organs. Two forms of Klotho, the cell membrane and secreted form, have pleiotropic activities that include regulation of general metabolism, oxidative stress, and mineral metabolism that correlates with its effect on accelerating aging. Membrane Klotho serves as an obligate co-receptor for the fibroblast growth factor (FGF), while secreted Klotho plays its role as a humoral factor. Klotho protein participates in the regulation of several biological activities, including regulation of calcium-phosphate homeostasis and PTH as well as vitamin D metabolism. The active form of vitamin D, 1,25(OH)₂D₃ (1,25-dihydroxy-vitamin D3 = calcitriol), acts as a neurosteroid that participates in the regulation of multiple brain functions. It provides neuroprotection and suppresses oxidative stress, inhibits inflammation and inflammatory mediators, and stimulates various neurotrophins. Calcitriol is involved in many brain-related diseases, including multiple sclerosis, Alzheimer´s disease, Parkinson´s disease, and schizophrenia. This review covers the most recent advances in Klotho research and discusses Klotho-dependent roles of calcitriol in neuro-psycho-pathophysiology.

Background/aims: Neuroendocrine dysregulation has been associated with rheumatoid arthritis (RA). Tyrosine hydroxylase (TH), a rate-limiting enzyme for synthesis of neuroendocrine hormones such as epinephrine, is also expressed in T lymphocytes and regulates balance between helper T (Th) 17 cells and regulatory T (Treg) cells. Herein, we aimed to show that TH expression in joints alleviates joint inflammation and Th17/Treg imbalance in collagen-induced arthritis (CIA), an animal model of RA, and these effects may be implemented by the mechanism of epinephrine action on α1-adrenoreceptor (α1-AR) in T cells.

Methods: CIA was prepared by intradermal injection of collagen type II in tail base of DBA1/J mice. On the 33rd day post-immunization, lentiviral vectors encoding TH or TH shRNA were injected into ankle joints of CIA mice. Limb inflammation of the mice was assessed beginning from day 21 until day 69 post-immunization by measurement of limb swelling, erythema and rigidity. Th17 and Treg differentiation and function in ankle joints were assessed on day 69 post-immunization by test of the expression of Th17 transcriptional factor ROR-γt and the levels of proinflammatory cytokines interleukin (IL)-17 and IL-22 as well as the expression of Treg transcriptional factor Foxp3 and the levels of antiinflammatory cytokines transforming growth factor (TGF)-β1 and IL-10. T cells were obtained from the spleen of mice that had been immunized with collagen type II 41 day earlier and treated with epinephrine or α1-AR agonist phenylephrine in vitro. Flow cytometry was used to analyze the percentages of CD25^-IL-17⁺ cells and CD25⁺Foxp3⁺ cells in CD4⁺ T cells.

Results: TH gene overexpression in ankle joints of CIA mice reduced limb inflammation and Th17-related transcription factor expression and inflammatory cytokine production but increased Treg-related antiinflammatory cytokine production in the joints. In contrast, TH gene silence in ankle joints of CIA mice enhanced limb inflammation and Th17 cell activity but decreased Treg cell function in the joints. Epinephrine upregulated α1-AR expression in T cells derived from CIA mice. Both epinephrine and phenylephrine reduced CIA-induced Th17 transcription factor expression and inflammatory cytokine production but enhanced Treg antiinflammatory cytokine production in vitro.

Conclusion: Upregulating TH expression in joints alleviates joint inflammation and Th17/Treg imbalance in CIA at least partially by enhancing epinephrine action on α1-AR in T cells.

The consumption of dairy products, particularly of low fat milk, has been shown to be associated with the occurrence of Parkinson's disease. This association does not necessarily reflect a pathophysiological role of milk intake in the development of Parkinson's disease. Nevertheless, the present review discusses a potential mechanism possibly mediating an effect of milk consumption on Parkinson's disease. The case is made that milk is tailored in part to support bone mineralization of the suckling offspring and is thus rich in calcium and phosphate. Milk intake is thus expected to enhance intestinal calcium phosphate uptake. As binding to fatty acids impedes Ca²⁺ absorption, low fat milk is particularly effective. Calcium and phosphate uptake inhibit the formation of 1,25(OH)₂D₃ (1,25-dihydroxy-vitamin D3 = calcitriol), the active form of vitamin D. Calcium inhibits 1,25(OH)₂D₃ production in part by suppressing the release of parathyroid hormone, a powerful stimulator of 1,25(OH)₂D₃ formation. Phosphate excess stimulates the release of fibroblast growth factor FGF23, which suppresses 1,25(OH)₂D₃ formation, an effect requiring Klotho. 1,25(OH)₂D₃ is a main regulator of mineral metabolism, but has powerful effects apparently unrelated to mineral metabolism, including suppression of inflammation and influence of multiple brain functions. In mice, lack of 1,25(OH)₂D₃ and excessive 1,25(OH)₂D₃ formation have profound effects on several types of behavior, such as explorative behavior, anxiety, grooming and social behavior. 1,25(OH)₂D₃ is produced in human brain and influences the function of various structures including substantia nigra. In neurons 1,25(OH)₂D₃ suppresses oxidative stress, inhibits inflammation and stimulates neurotrophin formation thus providing neuroprotection. As a result, 1,25(OH)₂D₃ is considered to favorably influence the clinical course of Parkinson's disease. In conclusion, consumption of milk could in theory accelerate the downhill course of neuronal function in Parkinson's disease. However, substantial additional experimentation is required to define the putative causal role of 1,25(OH)₂D₃ in the pathophysiology of Parkinson's disease and its sensitivity to milk consumption.