Catalytically Active Amyloids as Future Bionanomaterials.

Peptides and proteins can aggregate into highly ordered and structured conformations called amyloids. These supramolecular structures generally have convergent features, such as the formation of intermolecular beta sheets, that lead to fibrillary architectures. The resulting fibrils have unique mechanical properties that can be exploited to develop novel nanomaterials. In recent years, sequences of small peptides have been rationally designed to self-assemble into amyloids that catalyze several chemical reactions. These amyloids exhibit reactive surfaces that can mimic the active sites of enzymes. In this review, I provide a state-of-the-art summary of the development of catalytically active amyloids. I will focus especially on catalytic activities mediated by hydrolysis, which are the most studied examples to date, as well as novel types of recently reported activities that promise to expand the possible repertoires. The combination of mechanical properties with catalytic activity in an amyloid scaffold has great potential for the development of future bionanomaterials aimed at specific applications.

Glucose-6-phosphate dehydrogenase immobilized onto magnetic beads (G6PDH-Mb) as a generator system for production of NADPH: Development and application in metabolism studies.

Reduced nicotinamide adenine dinucleotide phosphate (NADPH) participates in several anabolic and catabolic pathways, being essential in numerous biochemical reactions involving energy release. Most of these reactions require a high amount of NADPH, which can be expensive from an industry point of view. Thus, biotechnology industries developed a great interest in NADPH production. Currently, there are different ways to obtain NADPH in situ, however, the most common is by enzymatic reactions, known as generator systems. Although this approach can be beneficial in terms of cost, the major drawback is the impossibility of reusing the enzyme. To overcome this, enzyme immobilization is a proven alternative. Herein, we report the use of glucose-6-phosphate dehydrogenase immobilized onto magnetic beads (G6PDH-Mb) through glutaraldehyde coupling to produce high amounts of NADPH. The G6PDH-Mbs were kinetically characterized showing a sigmoidal curve. Besides, the stability was evaluated, and their reuse was demonstrated for a period superior to 40 days. The G6PDH-Mb was used to in situ production of the NADPH metabolism experiments, using human liver microsome solutions and either albendazole or fiscalin B as model targets. The production of in vitro metabolites from albendazole and fiscalin B was evaluated by comparing the use of NADPH generated in situ with those obtained by commercial NADPH. Moreover, the activity of the G6PDH-Mb was monitored after using it for five consecutive albendazole metabolism reactions, with only a minor decrease in the enzyme activity (3.58 ± 1.67%) after the fifth time of use. The higher concentration obtained when using the designed G6PDH-Mb generator system demonstrated proof of the concept and its applicability.

Novel Nutraceutical Compounds in Alzheimer Prevention.

Alzheimer's disease (AD) incidence is increasing worldwide at an alarming rate. Considering this increase, prevention efforts, stemming from scientific research, health education, and public policies, are critical. Clinical studies evidenced that healthy lifestyles along with natural multitarget and disease-modifying agents have a preventative impact on AD or mitigate symptoms in diagnosed patients. The pathological alterations of AD start 30 years before symptoms, and it is essential to develop the capacity to detect those changes. In this regard, molecular biomarkers that detect early pathological manifestations are helpful. Based on markers data, early preventive interventions could reduce more than 40% of AD cases. Protective actions include exercise, shown to induce neurogenesis, cognitive stimulation, intellectual-social activity, and nutrition among others. Mediterranean diet, preprobiotics, and nutraceuticals containing bioactive molecules with antioxidant and anti-inflammatory properties are relevant. Antiprotein aggregation molecules whose mechanisms were described are important. Anti-inflammatory agents with anti-aggregation properties that help to control cognitive impairment, include quercetin, biocurcumin, rosemarinic acid, and Andean shilajit. Anthocyanidins, e.g., delphinidin, malvidin, and natural flavonoids, are also included. Quercetin and hydroxy-tyrosol are antiaging molecules and could have anti-AD properties. We emphasize the relevance of nutraceuticals as a main actor in the prevention and/or control of dementia and particularly AD.

Association of Righ-Risk Human Papillomavirus and Ureaplasma parvum Co-Infections with Increased Risk of Low-Grade Squamous Intraepithelial Cervical Lesions.

OBJECTIVE: The present report investigated the rates of coinfections between high-rik human papillomavirus (hrHPV) and the most important human mycoplasmas including Mycoplasma hominis, M. genitalium, Ureaplasma urealyticum and U. parvum in cervical samples of asymptomatic brazilian population. METHODS: Were included a total of 283 women aged 25-64 years screened by Papanicolaou smears for determining cervical abnormalities, single-target polymerase chain reaction (PCR) and real-time PCR (rt-PCR) for hrHPV and mycoplasmas, respectively. RESULTS: A total of 273 (94.5%) women were negative for intraepithelial lesions or malignancy cytology (NILM) and 10 (3.5%) presented abnormal cytology, all low-grade intraepithelial lesions (LSIL). The prevalence of hrHPV was 12.7% and 53.7% for mycoplasmas. U. parvum was the most frequently bacteria detected, followed by Mycoplasma hominis and U. urealyticum. M. genitalium was not detected. Women positive for U. parvum presented a 5-fold increased risk of LSIL (OR = 5.33; 95% CI = 1.09-26.04, P = 0.02) and co-infections between U. parvum and hrHPV increased the risk for LSIL (OR = 3.88; 95% CI = 1.75-8.58, P = 0.0003). However, these associations were not dependent on the concentration of the bacteria. CONCLUSION: Our results reinforced the hypothesis that some mycoplasmas may play a role as cofactors in HPV-mediated cervical carcinogenesis, at least in some populations.
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MicroRNAs and Mammarenaviruses: Modulating Cellular Metabolism.

Mammarenaviruses are a diverse genus of emerging viruses that include several causative agents of severe viral hemorrhagic fevers with high mortality in humans. Although these viruses share many similarities, important differences with regard to pathogenicity, type of immune response, and molecular mechanisms during virus infection are different between and within New World and Old World viral infections. Viruses rely exclusively on the host cellular machinery to translate their genome, and therefore to replicate and propagate. miRNAs are the crucial factor in diverse biological processes such as antiviral defense, oncogenesis, and cell development. The viral infection can exert a profound impact on the cellular miRNA expression profile, and numerous RNA viruses have been reported to interact directly with cellular miRNAs and/or to use these miRNAs to augment their replication potential. Our present study indicates that mammarenavirus infection induces metabolic reprogramming of host cells, probably manipulating cellular microRNAs. A number of metabolic pathways, including valine, leucine, and isoleucine biosynthesis, d-Glutamine and d-glutamate metabolism, thiamine metabolism, and pools of several amino acids were impacted by the predicted miRNAs that would no longer regulate these pathways. A deeper understanding of mechanisms by which mammarenaviruses handle these signaling pathways is critical for understanding the virus/host interactions and potential diagnostic and therapeutic targets, through the inhibition of specific pathologic metabolic pathways.

[Epilepsias de origen metabólico en el neonato]. / Epilepsies of metabolic origin in the neonate.

Neurometabolic diseases that manifest seizures and epilepsy are a large group of inherited disorders. They can present at any age from the neonatal period to adolescence. The epileptic manifestations can be very varied and, in general, they are epilepsies refractory to antiepileptic drugs. Epileptic phenomenology does not contribute to the diagnosis. The inborn errors of metabolism that respond to the use of cofactors should be known. In acute decompensation, it is essential to provide nutritional, hydroelectrolytic and respiratory support. It is possible that in a few years we can detect the metabolomic profile of these diseases, thus knowing better the diagnosis non-invasively and offering greater therapeutic possibilities for their epilepsy and especially for the underlying disease. We must not forget the transitory metabolic disorders and the electrolyte imbalances within the causes of seizures, especially in the neonatal period, and must be identified and treated early to avoid major damages.

Las enfermedades neurometabólicas que manifiestan convulsiones y epilepsia constituyen un amplio grupo de trastornos hereditarios. Se pueden presentar a cualquier edad desde el período neonatal hasta la adolescencia. Las manifestaciones epilépticas pueden ser muy variadas y, en general, se trata de epilepsias refractarias a los fármacos antiepilépticos. La fenomenología epiléptica no contribuye al diagnóstico. Se deben conocer los errores innatos del metabolismo que responden al empleo de cofactores. En descompensaciones agudas es fundamental dar soporte nutricional, hidroelectrolítico y respiratorio. Es muy posible que en pocos años se pueda conocer el perfil metabolómico de estas enfermedades y así profundizar en el diagnóstico no invasivo y ofrecer mayores posibilidades terapéuticas para la epilepsia y especialmente para la enfermedad de base. No debemos olvidar los desórdenes metabólicos transitorios y los desequilibrios hidroelectrolíticos dentro de las causas de las convulsiones, en especial en el período neonatal, que se deben identificar y tratar precozmente para evitar daños mayores.

Epilepsias de origen metabólico en el neonato / Epilepsias de origen metabólico en el neonato

Las enfermedades neurometabólicas que manifiestan convulsiones y epilepsia constituyen un amplio grupo de trastornos hereditarios. Se pueden presentar a cualquier edad desde el período neonatal hasta la adolescencia. Las manifestaciones epilépticas pueden ser muy variadas y, en general, se trata de epilepsias refractarias a los fármacos antiepilépticos. La fenomenología epiléptica no contribuye al diagnóstico. Se deben conocer los errores innatos del metabolismo que responden al empleo de cofactores. En descompensaciones agudas es fundamental dar soporte nutricional, hidroelectrolítico y respiratorio. Es muy posible que en pocos años se pueda conocer el perfil metabolómico de estas enfermedades y así profundizar en el diagnóstico no invasivo y ofrecer mayores posibilidades terapéuticas para la epilepsia y especialmente para la enfermedad de base. No debemos olvidar los desórdenes metabólicos transitorios y los desequilibrios hidroelectrolíticos dentro de las causas de las convulsiones, en especial en el período neonatal, que se deben identificar y tratar precozmente para evitar daños mayores.

Neurometabolic diseases that manifest seizures and epilepsy are a large group of inherited disorders. They can present at any age from the neonatal period to adolescence. The epileptic manifestations can be very varied and, in general, they are epilepsies refractory to antiepileptic drugs. Epileptic phenomenology does not contribute to the diagnosis. The inborn errors of metabolism that respond to the use of cofactors should be known. In acute decompensation, it is essential to provide nutritional, hydroelectrolytic and respiratory support. It is possible that in a few years we can detect the metabolomic profile of these diseases, thus knowing better the diagnosis non-invasively and offering greater therapeutic possibilities for their epilepsy and especially for the underlying disease. We must not forget the transitory metabolic disorders and the electrolyte imbalances within the causes of seizures, especially in the neonatal period, and must be identified and treated early to avoid major damages.

Association of human papillomavirus and bacterial vaginosis with increased risk of high-grade squamous intraepithelial cervical lesions.

OBJECTIVE: To assess the rates of co-infections between human papillomavirus (HPV) and 13 key markers of bacterial vaginosis in cervical samples by multiplex polymerase chain reaction in a population with a high rate of abnormal cytology and a positive HPV test. METHODS: The study included a total of 213 women aged 18-72 years screened using Papanicolaou smears for determining cervical abnormalities and for HPV and bacterial vaginosis by single-target and multiplex polymerase chain reaction. RESULTS: A total of 83 (39%) women were negative for intraepithelial lesion or malignancy cytology and 130 (61%) had abnormal cytology. HPV-DNA prevalence was 69.9% and bacterial vaginosis was 72.7 %. Co-infections between bacterial vaginosis with HPV-DNA and high-risk HPV were associated with an increased risk for squamous intraepithelial lesions of low-grade cytology and high-grade squamous intraepithelial lesions plus cervical cancer. The most frequent bacterial vaginosis agent was Gardnerella vaginalis (33.8%), and co-infection with HPV-DNA and high-risk HPV increased the risk for squamous intraepithelial lesions of low grade cytology and high-grade squamous intraepithelial lesions plus cervical cancer. Co-infection between Megasphaera type I and high-risk HPV increased the risk for high-grade squamous intraepithelial lesions plus cervical cancer. CONCLUSIONS: Our results reinforce the hypothesis that some bacterial vaginosis agents may play a role as co-factors in HPV-mediated cervical carcinogenesis, at least in some populations.

Lisil-oxidasa (LOX) y proteinas tipo LOX: rol de amino-oxidasas, propiedades moleculares y cataliticas / Lysyl oxidase (LOX) and LOX-like proteins: role of amino-oxidases, molecular and catalytic properties / Lisil-oxidase (LOX) e proteinas tipo LOX: papel da amino-oxidases, propriedades moleculares e catalíticas

Las amino-oxidasas pertenecen a dos grupos de proteinas: flavoenzimas y quinoenzimas. La lisil-oxidasa (LOX) es una quinoenzima que contiene cobre y lisil-tirosil-quinona como cofactor. Los niveles de LOX aumentan en muchas enfermedades fibroticas y en algunos tumores promoviendo metastasis, mientras que la expresion de la enzima esta disminuida en enfermedades que involucran un deterioro en el metabolismo del cobre. Se discute el rol de LOX como amino-oxidasa en la catalisis de la desaminacion oxidativa de residuos de lisina en los precursores del colageno y de elastina, y la participacion de los restantes miembros de esta familia genica: LOXL1, LOXL2, LOXL3 y LOXL4, asi como sus propiedades moleculares. Se analizan su biosintesis, sus propiedades cataliticas y mecanismo de reaccion, cofactores e inhibidores y la expresion y respuesta a diversos efectores celulares.

Amino-oxidases belong to two groups of proteins: flavoenzymes and quinoenzymes. Lysyl oxidase (LOX) is a copper-containing quinoenzime, having lysyl-tyrosyl-quinone as cofactor. LOX levels are increased in many fibrotic diseases, and in some tumors promoting metastasis, while the enzyme expression is decreased in diseases that involve deterioration in copper metabolism. The role of LOX as amino oxidase in catalyzing the oxidative deamination of lysine residues in precursors of collagen and elastin is discussed, as well as the participation of other members of this gene family: LOXL1, LOXL2, LOXL3, and LOXL4, and their molecular properties. The biosynthesis, catalytic properties and reaction mechanism, cofactors and inhibitors, and the expression and response to various cellular effectors are analyzed.

As amina oxidases pertencem a dois grupos de proteínas: flavoenzimas e quinoenzimas. A lisil-oxidase (LOX) é uma quinoenzima contendo cobre e lisil-tirosil-quinona como cofator. Os níveis da enzima LOX aumentam em muitas doenças fibróticas e em alguns tumores promovendo metástase, enquanto que a expressão da enzima está reduzida em doenças que envolvem a deterioração no metabolismo do cobre. Discute-se o papel de LOX como amina oxidase na catálise a desaminação oxidativa de resíduos de lisina de precursores de colágeno e de elastina, e a participação dos outros membros desta família gênica: LOXL1, LOXL2, LOXL3 e LOXL4, bem como as suas propriedades moleculares. A sua biossíntese, as suas propriedades catalíticas e mecanismo de reação, cofatores e inibidores e a expressão e resposta a diversos efetores celulares são analisados.

Lisil-oxidasa (LOX) y proteinas tipo LOX: rol de amino-oxidasas, propiedades moleculares y cataliticas / Lysyl oxidase (LOX) and LOX-like proteins: role of amino-oxidases, molecular and catalytic properties / Lisil-oxidase (LOX) e proteinas tipo LOX: papel da amino-oxidases, propriedades moleculares e catalíticas

Las amino-oxidasas pertenecen a dos grupos de proteinas: flavoenzimas y quinoenzimas. La lisil-oxidasa (LOX) es una quinoenzima que contiene cobre y lisil-tirosil-quinona como cofactor. Los niveles de LOX aumentan en muchas enfermedades fibroticas y en algunos tumores promoviendo metastasis, mientras que la expresion de la enzima esta disminuida en enfermedades que involucran un deterioro en el metabolismo del cobre. Se discute el rol de LOX como amino-oxidasa en la catalisis de la desaminacion oxidativa de residuos de lisina en los precursores del colageno y de elastina, y la participacion de los restantes miembros de esta familia genica: LOXL1, LOXL2, LOXL3 y LOXL4, asi como sus propiedades moleculares. Se analizan su biosintesis, sus propiedades cataliticas y mecanismo de reaccion, cofactores e inhibidores y la expresion y respuesta a diversos efectores celulares.(AU)

Amino-oxidases belong to two groups of proteins: flavoenzymes and quinoenzymes. Lysyl oxidase (LOX) is a copper-containing quinoenzime, having lysyl-tyrosyl-quinone as cofactor. LOX levels are increased in many fibrotic diseases, and in some tumors promoting metastasis, while the enzyme expression is decreased in diseases that involve deterioration in copper metabolism. The role of LOX as amino oxidase in catalyzing the oxidative deamination of lysine residues in precursors of collagen and elastin is discussed, as well as the participation of other members of this gene family: LOXL1, LOXL2, LOXL3, and LOXL4, and their molecular properties. The biosynthesis, catalytic properties and reaction mechanism, cofactors and inhibitors, and the expression and response to various cellular effectors are analyzed.(AU)

As amina oxidases pertencem a dois grupos de proteínas: flavoenzimas e quinoenzimas. A lisil-oxidase (LOX) é uma quinoenzima contendo cobre e lisil-tirosil-quinona como cofator. Os níveis da enzima LOX aumentam em muitas doenþas fibróticas e em alguns tumores promovendo metástase, enquanto que a expressÒo da enzima está reduzida em doenþas que envolvem a deterioraþÒo no metabolismo do cobre. Discute-se o papel de LOX como amina oxidase na catálise a desaminaþÒo oxidativa de resíduos de lisina de precursores de colágeno e de elastina, e a participaþÒo dos outros membros desta família gÛnica: LOXL1, LOXL2, LOXL3 e LOXL4, bem como as suas propriedades moleculares. A sua biossíntese, as suas propriedades catalíticas e mecanismo de reaþÒo, cofatores e inibidores e a expressÒo e resposta a diversos efetores celulares sÒo analisados.(AU)

Convulsiones neonatales refractarias / Neonatal refractory seizures

Las convulsiones del período neonatal y del primer año de vida pueden tener un origen, un tratamiento y un pronóstico muy distintos y serán el neonatólogo y el neuropediatra quienes mejor las conozcan y manejen con mayor experiencia. Existen formas graves de encefalopatía epiléptica del período neonatal como el Sídrome Ohtahara o la encefalopatía mioclónica de Aicardi, con un pronóstico muy reservado y una elevada morbimortalidad. Además existen algunas formas de convulsiones y epilepsias del período neonatal y del lactante joven que no responden al empleo de fármacos antiepilépticos (FAEs). En esta situación el iniciar precozmente otro tipo de terapia puede evitar el deterioro neurológico que, sin duda debido a las crisis convulsivas, se producirá y podrá permitir al paciente llevar una vida normal con la única obligación de tomar de por vida una medicación distinta de los FAEs. Revisamos el grupo de defectos metabólicos que dan lugar a convulsiones y epilepsias y cuyo tratamiento es muy distinto al de una epilepsia. Incluimos en esta revisión algunas formas de convulsiones y epilepsias del lactante joven que tienen en la actualidad tratamiento efectivo mediante sustancias totalmente distintas de los FAEs.

Convulsions appearing in the neonatal or first year of life can have a very different origin, treatment or prognosis and it shall be up to the neonatologist or neuropediatrician to resolve the problem since they are the ones who know their patients best. There are severe forms of epileptic encephalopathy in the neonatal period such as Ohtahara syndrome or Aicardi myoclonic encephalopathy with poor prognosis and high morbimortality. Furthermore, there are forms of convulsions and epilepsies during the neonatal and infant period which do not respond to AED. In such cases, it is important to initiate as soon as possible another type of treatment to prevent a neurological deterioration due to repeated convulsion crises and thus allow the patients to lead a normal life with the only obligation to take a different medication from AED during their whole life. We discuss the metabolic defects which lead to convulsions and epilepsies and their various treatments. We also include a revision of some forms of convulsions and epilepsies in the infant insisting on treatments with substances completely different from AEDs.

Disección aórtica, urgencia cardiológica y su relación con hiperhomocistinemia, marcador sérico. Hospital Dr. Teodoro Maldonado Carbo, Guayaquil 1999-2000 / Aortic dissection, cardiological emergency and its Relation with hyperhomocysteinemia serum marker at the Dr. Teodoro Maldonado Carbo Hospital in Guayaquil 1999-2000

Diseño: Estudio cerrado realizado en el área de emergencia del hospital ¡§Dr. Teodoro Maldonado Carbo¡¨ del Instituto Ecuatoriano de Seguridad Social, con estigmas de dolor torácico o falla cardiaca, cuyo antecedente fue la hipertensión arterial, en quienes se analizó muestras sanguíneas para detectar homocisteina en ayunas, durante las primeras 24 horas de su ingreso.Objetivo: Evaluar prospectivamente, el riesgo de disección aórtica asociada a niveles plasmáticos elevados de homocisteina.Universo: 120 pacientes, raza mestiza, grupo etario comprendido entre los 28 y 71 años; edad promedio 65 años, predominio masculino, sin infarto de miocardio previo; 25 pacientes desarrollaron urgencias hipertensivas, edema agudo de pulmón; 61 pacientes síndrome coronario agudo, angina de clase III de Brauwald, y 34 pacientes se complicaron con disección aórtica.Medición del estudio: En quienes con hipertensión arterial, se relacionaban con hiperhomocistinemia y el desarrollo de disección aórtica.Propósito: Diagnóstico precoz de disección, algoritmo, protocolo específico ante esta patología con el uso de vasodilatadores, beta bloqueadores, cofactores enzimáticos, vitamina B6, ácido fólico, acetilcisteina, hasta su estabilización hemodinámica.

Design: Study of a population that went to the emergency room of the Dr. Teodoro Maldonado Carbo Hospital of the Ecuadorian Social Security Institute, with thoracic pain or heart failure who have a clinical history of hypertension in which we determined homocystein levels in the blood, during the first 24 hrs of the patients¡¦ arrival to the emergency room.Objective: A prospective study of the association of aortic dissection risk with the high blood levels of homocystein.Universe: 120 patients of racially mixed race, among the ages of 28-71 years being the average of 65 year of age being predominantly male, without a clinical history of myocardial infraction, 25 patients developed hypertensive emergencies and acute pulmonary edema, 61 patients developed acute coronary syndrome, class III Angina of the Brauwald, and 34 patients got complicated with aortic dissection.Measurement of the study: The relationship that exists in patients who have hypertension and development of hyperhomocysteinemia and aortic dissection. Purpose: „XTo be able to diagnose early an aortic dissection.„XTo have a specific protocol in the use of vasodilatators, beta blockers, enzymatic cofactors vitamin b6, folic Acid, acetilcystein until the patient is hemodinamically stable. Results: The homocystein levels were higher in patients with aortic dissection, 56% plasmatic level than 15umol/ml, the other patients that developed acute pulmonary edema were treated with the conventional therapy