Evaluation of the safety profile of the quadrivalent vaccine against human papillomavirus in the risk of developing autoimmune, neurological, and hematological diseases in adolescent women in Colombia.

BACKGROUND: Cervical cancer eradication is one of the main goals for 2030 by the World Health Organization, which can only be achieved with high vaccination rates against Human Papilloma Virus. In Colombia, more and better scientific evidence is required to increase confidence in vaccination. The objective of this study is to evaluate the safety profile of the quadrivalent vaccine against HPV in the risk of developing autoimmune, neurological, and hematological diseases in adolescent women in Colombia. METHODS: We designed a cohort study based on national HPV vaccination records and incident diagnostic data for the diseases of special interest during 2012 and 2021. We included adolescent women between 9 and 19 years old and compared vaccinated and non-vaccinated cohorts using an Inverse Probability of Treatment Weighting (IPWT) method for each scenario disease and follow-up period (180 and 360 days). FINDINGS: The Odds Ratio (OR) of developing diseases of interest was estimated during two follow up periods, 180 and 360 days after the follow-up index date (Vaccination Day). The OR for developing rheumatoid arthritis was 4·4; CI95% (1·74 - 11·14), juvenile idiopathic arthritis was 2·76 IC95% (1·50 - 5·11), idiopathic thrombocytopenic purpura was 2·54 IC95% (1·28 - 5·02) and thyrotoxicosis was 2·86 IC95% (1·03 - 7·95), when comparing the vaccinated versus unvaccinated population. However, the temporal distribution of cases incident did not reveal a clear difference between the cohorts, since the rate of appearance of new cases has a constant linear behavior for the two groups. INTERPRETATION: For rheumatoid arthritis, juvenile idiopathic arthritis, idiopathic thrombocytopenic purpura, and thyrotoxicosis; the application of the vaccine had an effect on the development of the disease. Nevertheless, our results should be interpreted with caution and be further studied, considering that the biological plausibility of the events occurred without a clear temporal pattern in relation to the exposure to the vaccine.

Epileptogénesis y corteza piriforme: entendiendo a la epilepsia del lóbulo temporal más allá del hipocampo / Epileptogenesis and the piriform cortex: understanding temporal lobe epilepsy beyond the hippocampus

Introducción: Con la experiencia de los registros electroencefalográficos invasivos y el fracaso quirúrgico después de la cirugía, se ha hecho evidente que la epilepsia del lóbulo temporal es mucho más compleja de lo que se creía, y en la actualidad es considerada una enfermedad de redes anatomofuncionales y no de lesiones estructurales. Contenido: La información neurofisiológica e imagenológica actual permite concluir que en esta epilepsia están involucradas varias redes neuronales temporales y extratemporales que contribuyen a la extensión de la zona epileptógena. Una forma de entender el concepto de red epiléptica en la epilepsia del lóbulo temporal es a partir del conocimiento de la corteza piriforme. Varios estudios clínicos han mostrado que en pacientes con epilepsia del lóbulo temporal asociada a esclerosis hipocampal existe una disfunción interictal del procesamiento olfatorio que es más significativa, en comparación con pacientes con epilepsia focal extrahipocampal y controles sanos. Esta alteración es, probablemente, la consecuencia de una red neuronal disfuncional que se extiende más allá del hipocampo y que afecta a otras estructuras cercanas, incluida la corteza piriforme. Conclusión: En este artículo llevamos a cabo una revisión narrativa de la literatura con el objetivo de establecer un vínculo entre la corteza piriforme y la epileptogénesis del lóbulo temporal, y demostramos que esta enfermedad es la consecuencia de una disfunción de redes neuronales que no depende exclusivamente de una anormalidad estructural en el hipocampo o en estructuras cercanas.

Introduction: With the experience of invasive EEG recordings and surgical failure after surgery, it has become clear that temporal lobe epilepsy is much more complex than previously thought, and currently, is conceptualized as a disease of anatomical networks instead of structural lesions. Content: The current neurophysiological and imaging information allows us to conclude that several temporal and extratemporal anatomical networks are involved in this type of epilepsy. One way of understanding the concept of the epileptic network in temporal lobe epilepsy is from the knowledge of the piriform cortex. Several clinical studies have shown that in patients with temporal lobe epilepsy associated with hippocampal sclerosis exists an interictal dysfunction of olfactory processing that is more significant compared to patients with focal extra-hippocampal epilepsy and healthy controls. This alteration is probably the consequence of a dysfunctional neural network that extends beyond the hippocampus and affects other nearby structures, including the piriform cortex. Conclusion: In this article, we carry out a narrative review of the literature with the aim of establishing a link between the piriform cortex and temporal lobe epileptogenesis, demonstrating that this disease is the consequence of a dysfunctional network that does not depend exclusively of a hippocampal structural abnormality.

Green Synthesis and Antiproliferative Activity of Gold Nanoparticles of a Controlled Size and Shape Obtained Using Shock Wave Extracts from Amphipterygium adstringens.

In this study, green chemistry was used as a tool to obtain gold nanoparticles using Amphipterygium adstringens extracts as a synthesis medium. Green ethanolic and aqueous extracts were obtained using ultrasound and shock wave-assisted extraction. Gold nanoparticles with sizes ranging between 100 and 150 nm were obtained with ultrasound aqueous extract. Interestingly, homogeneous quasi-spherical gold nanoparticles with sizes between 50 and 100 nm were achieved with shock wave aqueous-ethanolic extracts. Furthermore, 10 nm gold nanoparticles were obtained by the traditional methanolic macerate extraction method. The physicochemical characteristics, morphology, size, stability, and Z potential of the nanoparticles were determined using microscopic and spectroscopic techniques. The viability assay in leukemia cells (Jurkat) was performed using two different sets of gold nanoparticles, with final IC50 values of 87 µM and 94.7 µM, reaching a maximum cell viability decrease of 80% The results do not indicate a significant difference between the cytotoxic effects produced by the gold nanoparticles synthesized in this study and vincristine on normal lymphoblasts (CRL-1991).

Maternal outcomes according to the type of placenta previa in a high complexity hospital in Cali, Colombia. Retrospective cohort study / Desenlaces maternos según el tipo de placenta previa en un hospital de alta complejidad en Cali, Colombia. Estudio de cohorte retrospectivo

Objectives: To describe the frequency of maternal complications in pregnant women with major or minor placenta previa (PP), and to assess a potential association between PP type and the presence of severe maternal bleeding and other associated outcomes. Materials and methods: Retrospective descriptive cohort. The study included pregnant women with 20 weeks of gestation or more and a confirmed diagnosis of placenta previa who were seen in a high complexity hospital in Cali (Colombia), between January 2011 and December 2020. Women with a diagnosis of placenta previa and concomitant placenta accreta were excluded. The collected variables were maternal age, body mass index, smoking, obesity, parity, presence of bleeding, postpartum hemorrhage, management of postpartum hemorrhage, transfusion, and maternal ICU admission. A descriptive analysis was performed. The protocol was approved by the ethics committee of Fundaciónn Valle de Lili. Results: A total of 146 patients met the inclusion criteria. The population consisted of women with a mean age of 32 years, with no history of prior surgery, with a prenatal diagnosis of placente previa at week 22; 70 % were major placenta previa cases. The most frequent complications were postpartum hemorrhage (37.9 % vs. 16.3 % for patients with major and minor placenta previa, respectively), transfusion requirement (23.3 and 9.3 %, respectively), and maternal ICU admission (40.8 % vs. 18.6 %, respectively). There were no cases of maternal death. Conclusions: There is a high frequency of complications in women with placenta previa, and it is probably higher in cases of major placenta previa. Further studies are needed to compare the frequency of maternal complications according to the type of placenta previa.

Objetivos: describir la frecuencia de complicaciones maternas en mujeres gestantes con placenta previa (PP) mayor o menor y evaluar una posible asociación entre tipo de PP y la presencia de hemorragia materna severa y otros resultados maternos asociados. Materiales y métodos: cohorte retrospectiva, descriptiva. Se incluyeron gestantes con 20 semanas o más de embarazo, con diagnóstico confirmado de placenta previa, quienes fueron atendidas en un hospital de alto nivel de complejidad localizado en Cali (Colombia), entre enero de 2011 y diciembre de 2020. Se excluyeron las gestantes con diagnóstico de placenta previa y acretismo placentario concomitante. Las variables recolectadas fueron: edad materna, índice de masa corporal, tabaquismo, obesidad, paridad, presencia de sangrado, hemorragia posparto, manejo de la hemorragia posparto, transfusión y admisión a UCI de la gestante. Se realizó análisis descriptivo. El protocolo fue aprobado por el comité de ética de la Fundación Valle de Lili. Resultados: 146 pacientes cumplieron con los criterios de inclusión. La población estuvo constituida por mujeres con una mediana de edad de 32 años, sin antecedente quirúrgico, con diagnóstico prenatal de placenta previa a la semana 22. En el 70,5 % de los casos se trató de pacientes con placenta previa mayor. Las complicaciones más frecuentes fueron hemorragia posparto (37,9 % vs. 16,3 % para pacientes con placenta previa mayor y menor, respectivamente), requerimiento de transfusión (23,3 y 9,3 %, respectivamente) y el ingreso materno a la UCI (40,8 % vs. 18,6 %, respectivamente). No se registraron muertes maternas. Conclusiones: las mujeres con placenta previa experimentan una frecuencia elevada de complicaciones; probablemente, dicha frecuencia es más alta cuando se documenta placenta previa mayor. Se requieren más estudios que comparen la frecuencia de complicaciones maternas según el tipo de placenta previa.

Desenlaces maternos según el tipo de placenta previa en un hospital de alta complejidad en Cali, Colombia. Estudio de cohorte retrospectivo / Maternal outcomes according to the type of placenta previa in a high complexity hospital in Cali, Colombia. Retrospective cohort study

Objetivos: Describir la frecuencia de complicaciones maternas en mujeres gestantes con placenta previa (PP) mayor o menor y evaluar una posible asociación entre tipo de PP y la presencia de hemorragia materna severa y otros resultados maternos asociados. Materiales y métodos: Cohorte retrospectiva, descriptiva. Se incluyeron gestantes con 20 semanas o más de embarazo, con diagnóstico confirmado de placenta previa, quienes fueron atendidas en un hospital de alto nivel de complejidad localizado en Cali (Colombia), entre enero de 2011 y diciembre de 2020. Se excluyeron las gestantes con diagnóstico de placenta previa y acretismo placentario concomitante. Las variables recolectadas fueron: edad materna, índice de masa corporal, tabaquismo, obesidad, paridad, presencia de sangrado, hemorragia posparto, manejo de la hemorragia posparto, transfusión y admisión a UCI de la gestante. Se realizó análisis descriptivo. El protocolo fue aprobado por el comité de ética de la Fundación Valle de Lili. Resultados: 146 pacientes cumplieron con los criterios de inclusión. La población estuvo constituida por mujeres con una mediana de edad de 32 años, sin antecedente quirúrgico, con diagnóstico prenatal de placenta previa a la semana 22. En el 70,5 % de los casos se trató de pacientes con placenta previa mayor. Las complicaciones más frecuentes fueron hemorragia posparto (37,9 % vs. 16,3 % para pacientes con placenta previa mayor y menor, respectivamente), requerimiento de transfusión (23,3 y 9,3 %, respectivamente) y el ingreso materno a la UCI (40,8 % vs. 18,6 %, respectivamente). No se registraron muertes maternas. Conclusiones: Las mujeres con placenta previa experimentan una frecuencia elevada de complicaciones; probablemente, dicha frecuencia es más alta cuando se documenta placenta previa mayor. Se requieren más estudios que comparen la frecuencia de complicaciones maternas según el tipo de placenta previa.

Objectives: To describe the frequency of maternal complications in pregnant women with major or minor placenta previa (PP), and to assess a potential association between PP type and the presence of severe maternal bleeding and other associated outcomes. Material and methods: Retrospective descriptive cohort. The study included pregnant women with 20 weeks of gestation or more and a confirmed diagnosis of placenta previa who were seen in a high complexity hospital in Cali (Colombia), between January 2011 and December 2020. Women with a diagnosis of placenta previa and concomitant placenta accreta were excluded. The collected variables were maternal age, body mass index, smoking, obesity, parity, presence of bleeding, postpartum hemorrhage, management of postpartum hemorrhage, transfusion, and maternal ICU admission. A descriptive analysis was performed. The protocol was approved by the ethics committee of Fundaciónn Valle de Lili. Results: A total of 146 patients met the inclusion criteria. The population consisted of women with a mean age of 32 years, with no history of prior surgery, with a prenatal diagnosis of placente previa at week 22; 70% were major placenta previa cases. The most frequent complications were postpartum hemorrhage (37.9 % vs. 16.3 % for patients with major and minor placenta previa, respectively), transfusion requirement (23.3 and 9.3 %, respectively), and maternal ICU admission (40.8 % vs. 18.6 %, respectively). There were no cases of maternal death. Conclusions: There is a high frequency of complications in women with placenta previa, and it is probably higher in cases of major placenta previa. Further studies are needed to compare the frequency of maternal complications according to the type of placenta previa.

House fly (Musca domestica) larvae meal as an ingredient with high nutritional value: Microencapsulation and improvement of organoleptic characteristics.

Insects have potential to become food ingredients, but it is necessary to improve the sensory properties of insects to help them to be better accepted by the population. The purpose of this study was to produce and characterize house fly larval meal (FLM) converted to a micro-encapsulated powder to improve appearance and other organoleptic characteristics. FLM showed high protein (54%) and lipid (22%) content, with a microbiological activity compatible for food purposes. Moreover, the high content of essentials amino acids (lysine, cysteine and leucine) and unsaturated fatty acids (oleic, linoleic and palmitoleic) make FLM a valuable nutritional source. Spray drying was selected to encapsulate FLM (0.5-2% w/v) using maltodextrin (20% w/v) and alginate (0.5% w/v). Encapsulation improved the appearance of FLM, creating a white-beige, monodispersed micro-powder (9 µm in size). Micro-powder with 2% FLM is considered a good source of protein (5.1%). Microencapsulation also dramatically reduced the volatile emissions of FLM. In conclusion, novel FLM micro-powders were developed using a simple and scalable encapsulation technique. The micro-powder with 2% FLM is a good source of protein, has a pleasant appearance similar to vegetable meals and has improved odor compared to typical insect meals. Thus, insect-based food ingredients in micro-powders could become more accepted by the general population.

Increased dietary availability of selenium in rainbow trout (Oncorhynchus mykiss) improves its plasma antioxidant capacity and resistance to infection with Piscirickettsia salmonis.

Salmonid Rickettsial Septicaemia (SRS), caused by Piscirickettsia salmonis, is the most important infectious disease in the Chilean salmon farming industry. An opportunity to control this disease is to use functional micronutrients to modulate host mechanisms of response to the infection. Since P. salmonis may affect the host antioxidant system in salmonids, particularly that dependent on selenium (Se), we hypothesized that fish's dietary selenium supplementation could improve the response to the bacterial infection. To address this, we defined a non-antibiotic, non-cytotoxic concentration of selenium to evaluate its effect on the response to in vitro infections of SHK-1 cells with P. salmonis. The results indicated that selenium supplementation reduced the cytopathic effect, intracellular bacterial load, and cellular mortality of SHK-1 by increasing the abundance and activity of host glutathione peroxidase. We then prepared diets supplemented with selenium up to 1, 5, and 10 mg/kg to feed juvenile trout for 8 weeks. At the end of this feeding period, we obtained their blood plasma and evaluated its ability to protect SHK-1 cells from infection with P. salmonis in ex vivo assays. These results recapitulated the observed ability of selenium to protect against infection with P. salmonis by increasing the concentration of selenium and the antioxidant capacity in fish's plasma. To the best of our knowledge, this is the first report of the protective capacity of selenium against P. salmonis infection in salmonids, becoming a potential effective host-directed dietary therapy for SRS and other infectious diseases in animals at a non-antibiotic concentration.

Pharmacological iron-chelation as an assisted nutritional immunity strategy against Piscirickettsia salmonis infection.

Salmonid Rickettsial Septicaemia (SRS), caused by Piscirickettsia salmonis, is a severe bacterial disease in the Chilean salmon farming industry. Vaccines and antibiotics are the current strategies to fight SRS; however, the high frequency of new epizootic events confirms the need to develop new strategies to combat this disease. An innovative opportunity is perturbing the host pathways used by the microorganisms to replicate inside host cells through host-directed antimicrobial drugs (HDAD). Iron is a critical nutrient for P. salmonis infection; hence, the use of iron-chelators becomes an excellent alternative to be used as HDAD. The aim of this work was to use the iron chelator Deferiprone (DFP) as HDAD to treat SRS. Here, we describe the protective effect of the iron chelator DFP over P. salmonis infections at non-antibiotic concentrations, in bacterial challenges both in vitro and in vivo. At the cellular level, our results indicate that DFP reduced the intracellular iron content by 33.1% and P. salmonis relative load during bacterial infections by 78%. These findings were recapitulated in fish, where DFP reduced the mortality of rainbow trout challenged with P. salmonis in 34.9% compared to the non-treated group. This is the first report of the protective capacity of an iron chelator against infection in fish, becoming a potential effective host-directed therapy for SRS and other animals against ferrophilic pathogens.

Resiliencia y constructos personales de victimización en individuos vulnerados por el conflicto armado / Resilience and personal constructions in individual victims in the armed conflict

El presente trabajo investigativo parte de la postura de que ahondar sobre el conflicto armado y sus efectos en la población colombiana, es referirse a un tema que durante años ha evolucionado en diferentes periodos trascendentales generando diversas posturas, pero que indudablemente solo se puede describir de manera particular por quien ha vivido el rigor de la lucha por el poder económico y político, teniendo en cuenta esto, se desarrolla un estudio mediante un paradigma explicativo e interpretativo que contempla una metodología mixta, dirigida a indagar la relación entre el nivel de resiliencia y los constructos personales de aquellos individuos vulnerados por el conflicto armado, evidenciándose una disonancia entre el análisis de los resultados, al hallarse habilidades resilientes en los sujetos desde lo cuantitativo, las cuales no estaban representadas, desde un foco cualitativo, en el discurso de la mayoría de individuos, pues su subjetividad refería constructos poco ligados a la resiliencia. En tanto, se devela la relevancia de ejecutar acciones no solo inclinadas en hacer una reparación desde lo legal, sino que traigan a colación las significaciones individuales de las víctimas, para que estas puedan trascender y superar las secuelas que dificultan el desarrollo en las dimensiones psicológicas, sociales y emocionales que de alguna manera prolongan el flagelo y perpetúan el asistencialismo.

This paper is part of an effort to try to go deeper into the armed conflict and its effect on the Colombian people, it refers to a topic that has evolved into transcendental periods creating diverse postures that can only be described by those who have lived the political and economic struggle. Taking this perspective into account, this study was carried out under an explanatory and interpretative paradigm using a mixed methodo- logy looking to analyze the relationship between the level of resilience and the personal construction of those individuals victims of the armed conflict, displaying a dissonance between the result analysis of the results in finding the resilient abilities in subjects using a quantitative perspective, since their subjectivity referred constructions that were not very resilient. Therefore, there is the relevance of carrying out actions not only meant to repair forma legal perspective but that bring meaning to individual victims so that they may transcend and overcome the aftermath that hinder the development of psychological, social and emotional dimensions that in some way or another elongate the pain and extend assistance.

Deprivation of folate and B12 increases neurodegeneration beyond that accompanying deprivation of either vitamin alone.

Increased homocysteine has in some cases been linked with an increased incidence of Alzheimer's disease and motor neuron disease. Folate or B12 deficiency increases homocysteine, but controversy exists as to whether their levels also correlate with either disorder. Since their presence within various dietary constituents may confound interpretation, we tested the impact of deprivation of either or both in the closed environment of neuronal cell cultures. Deprivation of either increased cytosolic calcium, reactive oxygen species, intracellular homocysteine, and apoptosis, but deprivation of both fostered substantially larger increases, supporting the notion that both are required for optimal neuroprotection.

A nanoemulsion formulation of tamoxifen increases its efficacy in a breast cancer cell line.

This paper reports on the preparation of a water-soluble nanoemulsion of the highly lipid-soluble drug tamoxifen (TAM). In addition, relative to a suspension of TAM, the nanoemulsion preparation demonstrated a greater zeta potential (increased negative charge) which has previously been associated with increasing drug/membrane permeability. This study also reports that relative to suspensions of TAM with particle sizes greater than 6000 nm, nanoemulsions of TAM, having mean particle sizes of 47 nm, inhibited cell proliferation 20-fold greater and increased cell apoptosis 4-fold greater in the HTB-20 breast cancer cell line. Thus, this work suggests that a nanoemulsion compared to a suspension preparation of TAM increases its anticancer properties relative to breast cancer.

Dynein mediates retrograde neurofilament transport within axons and anterograde delivery of NFs from perikarya into axons: regulation by multiple phosphorylation events.

We examined the respective roles of dynein and kinesin in axonal transport of neurofilaments (NFs). Differentiated NB2a/d1 cells were transfected with green fluorescent protein-NF-M (GFP-M) and dynein function was inhibited by co-transfection with a construct expressing myc-tagged dynamitin, or by intracellular delivery of purified dynamitin and two antibodies against dynein's cargo domain. Monitoring of the bulk distribution of GFP signal within axonal neurites, recovery of GFP signal within photobleached regions, and real-time monitoring of individual NFs/punctate structures each revealed that pertubation of dynein function inhibited retrograde transport and accelerated anterograde, confirming that dynein mediated retrograde axonal transport, while intracellular delivery of two anti-kinesin antibodies selectively inhibited NF anterograde transport. In addition, dynamitin overexpression inhibited the initial translocation of newly-expressed NFs out of perikarya and into neurites, indicating that dynein participated in the initial anterograde delivery of NFs into neurites. Delivery of NFs to the axon hillock inner plasma membrane surface, and their subsequent translocation into neurites, was also prevented by vinblastine-mediated inhibition of microtubule assembly. These data collectively suggest that some NFs enter axons as cargo of microtubues that are themselves undergoing transport into axons via dynein-mediated interactions with the actin cortex and/or larger microtubules. C-terminal NF phosphorylation regulates motor association, since anti-dynein selectively coprecipitated extensively phosphorylated NFs, while anti-kinesin selectively coprecipitated less phosphorylated NFs. In addition, however, the MAP kinase inhibitor PD98059 also inhibited transport of a constitutively-phosphorylated NF construct, indicating that one or more additional, non-NF phosphorylation events also regulated NF association with dynein or kinesin.

Folate, vitamin E, and acetyl-L-carnitine provide synergistic protection against oxidative stress resulting from exposure of human neuroblastoma cells to amyloid-beta.

Oxidative stress is an early and pivotal factor in Alzheimer's disease (AD). The neurotoxic peptide amyloid-beta (Abeta) contributes to oxidative damage in AD by inducing lipid peroxidation, which in turn generates additional downstream cytosolic free radicals and reactive oxygen species (ROS), leading to mitochondrial and cytoskeletal compromise, depletion of ATP, and ultimate apoptosis. Timely application of antioxidants can prevent all downstream consequences of Abeta exposure in culture, but in situ efficacy is limited, due in part to prior damage as well as difficulty in delivery. Herein, we demonstrate that administration of a combination of vitamin E (which prevents de novo membrane oxidative damage), folate (which maintains levels of the endogenous antioxidant glutathione), and acetyl-L-carnitine (which prevents Abeta-induced mitochondrial damage and ATP depletion) provides superior protection to that derived from each agent alone. These findings support a combinatorial approach in Alzheimer's therapy.

Neurofilaments can undergo axonal transport and cytoskeletal incorporation in a discontinuous manner.

Neurofilaments (NFs) are thought to provide structural support for axons. Some NFs exhibit an extended residence time along axons, the nature of which remains unclear. In prior studies in NB2a/d1 cells, hypophosphorylated NFs were demonstrated to be dispersed throughout the axon and to undergo relatively rapid axonal transport, while extensively phosphorylated NFs organized into a "bundle" localized along the center of the axon. It was not conclusively determined whether bundled NFs underwent transport or instead underwent turnover via exchange with transporting individual NFs. Herein, using transfection with multiple constructs and regional photobleaching, we demonstrate that bundled NFs undergo relatively slow transport as well as exchange with surrounding individual NFs. We also demonstrate that newly synthesized NFs disperse nonhomogenously throughout axonal neurites and perikarya. These findings provide a mechanism by which some NFs exhibit extended residence time within axons, which lessens the metabolic burden of cytoskeletal turnover.

Nanosphere-mediated delivery of vitamin E increases its efficacy against oxidative stress resulting from exposure to amyloid beta.

Oxidative stress is an early hallmark of affected neurons in Alzheimer's disease (AD). The antioxidant vitamin E provided limited neuroprotection in AD, which may have derived from its lipophilic nature and resultant inability to quench cytosolic reactive oxygen species (ROS), including those generated from antecedent membrane oxidative damage. We examined herein whether or not encapsulation into polyethylene glycol (PEG)-based nanospheres, which can enter the cytosol, improved the efficacy of vitamin E against amyloid-beta(Abeta)-induced ROS. Unexcapsulated vitamin E prevented Abeta-induced ROS in cultured SH-SY-5Y human neuroblastoma cells only if present prior to, or applied simultaneously with, Abeta treatment. By contrast, encapsulated vitamin E was equally effective if administered 1 hr after Abeta exposure. These findings suggest suggests that nanosphere-mediated delivery methods may be a useful adjunct for antioxidant therapy in AD.

Cdk5 inhibits anterograde axonal transport of neurofilaments but not that of tau by inhibition of mitogen-activated protein kinase activity.

Cyclin-dependent kinase 5 (cdk5) inhibits neurofilament (NF) anterograde axonal transport while p42/44 mitogen-activated protein kinase (MAPk) promotes it. Since cdk5 is known to inhibit MAP kinase activity, we examined whether or not cdk5 inhibits anterograde NF transport via inhibition of MAPk activity. To accomplish this, we manipulated the activity of these kinases in differentiated NB2a/d1 cells, and monitored anterograde axonal transport of green fluorescent protein-conjugated-NF-M (GFP-M) and cyan fluorescent protein-conjugated (CFP)-tau. The cdk5 inhibitor roscovitine increased anterograde axonal transport of GFP-M and CFP-tau; transfection with cdk5/p25 inhibited transport of both. Inhibition of MAPk activity by PD98059 or expression of dominant-negative MAPk inhibited anterograde GFP-M transport, while expression of constitutively active MAPk enhanced it; these treatments did not affect CFP-tau transport. PD98059 prevented roscovitine-mediated enhancement of GFP-M transport, but did not prevent enhancement of CFP-tau transport. Co-transfection with constitutively activated MAPk prevented the inhibition of GFP-M transport that normally accompanied transfection with cdk5/p25, but did not prevent inhibition of tau transport by cdk5/p25. Finally, the extent of inhibition of GFP-M axonal transport by PD98059 was not additive to that derived from transfection with cdk5/p35, and the increase in NF transport that accompanies roscovitine treatment was not additive to that derived from transfection with constitutively activated MAPk, suggesting that the influence of these kinases on NF transport was within the same, rather than distinct, pathways. These findings suggest that axonal transport of tau and NFs is under the control of distinct kinase cascades, and that cdk5 inhibits NF transport at least in part by inhibiting MAPk.

N-acteyl cysteine alleviates oxidative damage to central nervous system of ApoE-deficient mice following folate and vitamin E-deficiency.

Oxidative stress is an early neurodegenerative insult in Alzheimer's disease (AD). Antioxidant mechanisms, including elements of the glutathione (GSH) pathway, undergo at least a transient compensatory increase that is apparently insufficient due to continued oxidative damage during disease progression. Mice deficient in apolipoprotein E, which provide a model for some aspects of AD, undergo increased oxidative damage to brain tissue and cognitive decline when maintained on a folate-free diet, despite a compensatory increase in glutathione synthase transcription and activity as well as increased levels of GSH. Dietary supplementation with N-acetyl cysteine (1 g/kg diet), a cell-permeant antioxidant and GSH precursor, alleviated oxidative damage and cognitive decline, and restored glutathione synthase and GSH levels in ApoE-deficient mice deprived of folate to those of normal mice maintained in the presence of folate. These data support the administration of antioxidant precursors to buffer oxidative damage in neurodegenerative disorders.

Neurofilament transport is dependent on actin and myosin.

Real-time analyses have revealed that some newly synthesized neurofilament (NF) subunits translocate into and along axonal neurites by moving along the inner plasma membrane surface, suggesting that they may translocate against the submembrane actin cortex. We therefore examined whether or not NF axonal transport was dependent on actin and myosin. Perturbation of filamentous actin in NB2a/d1 cells with cytochalasin B inhibited translocation of subunits into axonal neurites and inhibited bidirectional translocation of NF subunits within neurites. Intravitreal injection of cytochalasin B inhibited NF axonal transport in optic axons in a dose-response manner. NF subunits were coprecipitated from NB2a/d1 cells by an anti-myosin antibody, and myosin colocalized with NFs in immunofluorescent analyses. The myosin light chain kinase inhibitor ML-7 and the myosin ATPase inhibitor 2,3-butanedione-2-monoxime perturbed NF translocation within NB2a/d1 axonal neurites. These findings suggest that some NF subunits may undergo axonal transport via myosin-mediated interactions with the actin cortex.

Reexpression of vimentin in differentiated neuroblastoma cells enhances elongation of axonal neurites.

Vimentin (Vm) is initially expressed by early neuronal precursors in situ and in culture. Vm is essential for neuritogenesis at least in culture and is gradually replaced by neurofilaments (NFs) because of down-regulation of Vm expression. This period is accompanied by a slowing of axonal elongation. We examined whether continued expression of Vm could foster continued axonal elongation. NB2a/d1 cells differentiated with dibutyryl cAMP were transfected with constructs expressing Vm or the middle-molecular-weight NF subunit (NF-M) each conjugated to green fluorescent protein (GFP). Axonal neurites of cells expressing GFP-Vm were 30% longer than those of nonexpressing cells, or cells expressing GFP-M, and exhibited a decrease in neurite caliber. Expression of GFP-M did not enhance axonal neurite length but significantly increased caliber. These findings provide further evidence of a role for Vm in axonal outgrowth. Culturing of nontransfected cells on laminin increased neurite length, but cells expressing GFP-Vm demonstrated an equivalent increase whether cultured on laminin or culture plastic. Axonal neurites of cells expressing GFP-Vm turned to avoid a nonfavorable substrate (nitrocellulose), but culturing of these cells on nitrocellulose did not impair axonal outgrowth. These latter findings indicate that the more robust outgrowth following reexpression of Vm is independent of a favorable or nonfavorable substrate but that axonal neurites of these cells still interact with the substrate to the extent that the substrate can influence directionality.