Infectious endocarditis without intracardiac devices or underlying structural heart disease.

OBJECTIVE: To describe clinical, microbiological and echocardiographic aspects of endocarditis in a specific group of patients without intracardiac devices or underlying structural heart disease. METHOD: Retrospective study, clinical records and echocardiographic reports were reviewed during the period 1997 to 2020. Duke's modified criteria were applied. Statistical analysis: univariate expressed in frequencies, using measures of dispersion and central tendency. RESULTS: 30,000 echocardiographic reports were reviewed, only 1350 had infectious endocarditis as a reason for sending, of which 248 cases were selected. The mean age was 48.1 ± 16.7 years. 140 men (56%) and 108 women (44%). The most frequent echocardiographic sign was vegetation, in 278 (93.60%), and most common location was mitral (35.55%), with a higher number of cases in the right ventricle than expected. The most common systemic disease was kidney disease, in 135 (41.08%). A case of Streptococcus thoraltensis not previously reported in Mexico was identified. CONCLUSIONS: The presence of infectious endocarditis has increased due to invasive in-hospital and drug procedures. Due to their complexity, multidisciplinary teams are indispensable.

OBJETIVO: Describir aspectos clínicos, microbiológicos y ecocardiográficos de endocarditis en un grupo específico de pacientes sin dispositivos intracardiacos ni cardiopatía estructural subyacente. MÉTODO: Estudio retrospectivo en el que se revisaron expedientes clínicos y reportes ecocardiográficos durante el periodo de 1997 a 2020. Se aplicaron los criterios modificados de Duke. Se describió la muestra por edad, sexo, enfermedad sistémica, vegetaciones y agente microbiológico. Se excluyeron pacientes con cardiopatía estructural o Libman-Sacks. Análisis estadístico: univariado expresado en frecuencias, utilizando medidas de dispersión y tendencia central. RESULTADOS: Se revisaron 30,000 reportes ecocardiográficos, de los cuales solo 1350 tenían como motivo de envío endocarditis infecciosa, y de estos se seleccionaron 248 casos. La edad promedio fue de 48.1 ± 16.7 años. Hubo 140 hombres (56%) y 108 mujeres (44%). El signo ecocardiográfico más frecuente fue la vegetación, en 278 (93.60%), y la ubicación más común fue mitral (35.55%), con un número mayor de casos en el ventrículo derecho de lo esperado. La enfermedad sistémica más común fue la enfermedad renal, en 135 (41.08%). Se identificó un caso de Streptococcus thoraltensis no reportado previamente en México. CONCLUSIONES: La presencia de endocarditis infecciosa ha aumentado debido a procedimientos invasivos intrahospitalarios y fármacos. Por su complejidad, los equipos multidisciplinarios son indispensables.

Co-infection patterns in the ectoparasitic community affecting the Iberian ibex Capra pyrenaica.

BACKGROUND: Sarcoptic mange is one of the main parasitic diseases affecting the Iberian ibex Capra pyrenaica. Scabietic animals suffer a decline in body condition and reproductive fitness and in severe cases may die. Although several previous studies of the pathology of this disease and the physiological changes it produces in ibex have been carried out in recent years, our knowledge of the relationship between Sarcoptes scabiei and other ectoparasites of this host is still limited. METHODS: We analysed 430 Iberian ibex skin samples. Ectoparasites were removed, counted and identified. Mite (S. scabiei) numbers were obtained after digesting the skin samples in a 5% KOH solution. We modelled mite numbers in terms of host sex and age, site, year, season and the presence of other ectoparasites such as ticks and lice using generalized linear mixed models (GLMMs) and ectoparasite co-occurrence patterns using two different models: the probabilistic model species co-occurrence and the generalized linear latent variable model (GLLVM). RESULTS: The ectoparasite community was mainly composed of S. scabiei, six ticks (Haemaphysalis sulcata, Haemaphysalis punctata, Rhipicephalus bursa, Rhipicephalus turanicus, Dermacentor marginatus and Ixodes ricinus) and two lice (Bovicola crassipes and Linognathus stenopsis). Adult male ibex harboured more mites than females. Mite numbers varied greatly spatially and seasonally and increased with the presence of other parasites. Some positive co-occurrence relationships between pairs of different ectoparasites were observed, particularly between ticks. The presence of S. scabiei negatively affected lice and H. sulcata numbers. CONCLUSIONS: Sarcoptic mange has spread above all in ibex populations in and around the Mediterranean Basin, where it is now found in almost a third of its host's range. Mite numbers varied seasonally and spatially and were higher in male hosts. The presence of S. scabiei had a negative effect on lice numbers but favoured the presence of ticks.

NRN1 Gene as a Potential Marker of Early-Onset Schizophrenia: Evidence from Genetic and Neuroimaging Approaches.

Included in the neurotrophins family, the Neuritin 1 gene (NRN1) has emerged as an attractive candidate gene for schizophrenia (SZ) since it has been associated with the risk for the disorder and general cognitive performance. In this work, we aimed to further investigate the association of NRN1 with SZ by exploring its role on age at onset and its brain activity correlates. First, we developed two genetic association analyses using a family-based sample (80 early-onset (EO) trios (offspring onset ≤ 18 years) and 71 adult-onset (AO) trios) and an independent case-control sample (120 healthy subjects (HS), 87 EO and 138 AO patients). Second, we explored the effect of NRN1 on brain activity during a working memory task (N-back task; 39 HS, 39 EO and 39 AO; matched by age, sex and estimated IQ). Different haplotypes encompassing the same three Single Nucleotide Polymorphisms(SNPs, rs3763180-rs10484320-rs4960155) were associated with EO in the two samples (GCT, TCC and GTT). Besides, the GTT haplotype was associated with worse N-back task performance in EO and was linked to an inefficient dorsolateral prefrontal cortex activity in subjects with EO compared to HS. Our results show convergent evidence on the NRN1 association with EO both from genetic and neuroimaging approaches, highlighting the role of neurotrophins in the pathophysiology of SZ.

Impacto en el proceso de cicatrización post extracción de terceros molares mandibulares con plaquetas rica en fibrina: Revisión de Literatura / Impact on the post extraction healing process of mandibular third molars with fibrin-rich platelets: Literature review

Resumen Diversos autores sostienen que la aplicación de plaquetas ricas en fibrina en el área de cirugía oral resulta beneficioso en el proceso de cicatrización por la liberación de factores de crecimiento y citocinas sumergidas en las plaquetas y la malla de fibrina misma que contiene leucocitos para resistir y combatir la infección formando hueso nuevo en los alvéolos post extracción. El objetivo es determinar el beneficio en el proceso de cicatrización post extracción de terceros molares mandibulares con plaquetas ricas en fibrina. La investigación es de tipo descriptiva, de carácter documental, de diseño no experimental y enfoque cualitativo. Se emplea la metodología PRISMA para la identificación, revisión e inclusión de los artículos científicos que forman parte del estudio. Se seleccionó los artículos tomando en cuenta el título, resumen y objetivo, considerados todos los estudios de revisiones sistemáticas, meta-análisis, estudios comparativos y revisiones de literatura que comprendan diferentes criterios acerca de la preservación del alveolo dentario posterior a cirugía de terceros molares con el uso de plaquetas ricas en fibrina. La búsqueda arrojó 9 en Pub Med y 201 en Google Académicos, 8 en Science Direct, determinando los criterios de exclusión excluyendo libros, monografías y estudios experimentales, quedó 175 artículos que no cumplen el objetivo a investigar, 22 estaban duplicados y 21 artículos se consideran incluidos en esta revisión de literatura. Los artículos fueron leídos en su total integridad, se analizó los artículos, objetivos, metodología y conclusión de cada uno de ellos lo cual fue expuesto a seguir y posteriormente analizados.

Abstract Several authors maintain that the application of fibrin-rich platelets in the oral surgery area is beneficial in the healing process due to the reléase of growth factors and cytokines submerged in the platelets and the fibrin mesh itself that contains leukocytes to resist and combat the infection forming new bone in the postextraction alveoli. The objective is to determine the Benefit in the healing process after extraction of mandibular third molars with fibrin-rich platelets. The research is exploratory, documentary, non-experimental design, and qualitative approach. The PRISMA methodology was used for the identification, review, selection, and inclusion of the scientific articles that are part of the study. The articles were selected taking into account the title, summary, and objective, regarding all studies of systematic reviews, meta-analyses, comparative studies, and literatura reviews comprising different criterio about the preservation of the dentary alveolus after surgery of third molars with the use of platelets rich in fibrin. The research yielded 9 in Pub Med and 201 in Google Academics, 8 in Science direct, establishing the exclusion criterio excluding books, monographs, and experimental studies, there were 175 articles that do not gather the objective to be investigated, 22 were duplicated and 21 articles are considered included in this literature review. The articles were read in their completeness, the articles were analyzed, objectives, methodology, and conclusion of each of them which was exposed to follow and subsequently examined.

Neuroprotective Fragment C of Tetanus Toxin Modulates IL-6 in an ALS Mouse Model.

Neuroinflammation plays a significant role in amyotrophic lateral sclerosis (ALS) pathology, leading to the development of therapies targeting inflammation in recent years. Our group has studied the tetanus toxin C-terminal fragment (TTC) as a therapeutic molecule, showing neuroprotective properties in the SOD1G93A mouse model. However, it is unknown whether TTC could have some effect on inflammation. The objective of this study was to assess the effect of TTC on the regulation of inflammatory mediators to elucidate its potential role in modulating inflammation occurring in ALS. After TTC treatment in SOD1G93A mice, levels of eotaxin-1, interleukin (IL)-2, IL-6 and macrophage inflammatory protein (MIP)-1 alpha (α) and galectin-1 were analyzed by immunoassays in plasma samples, whilst protein expression of caspase-1, IL-1ß, IL-6 and NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) was measured in the spinal cord, extensor digitorum longus (EDL) muscle and soleus (SOL) muscle. The results showed reduced levels of IL-6 in spinal cord, EDL and SOL in treated SOD1G93A mice. In addition, TTC showed a different role in the modulation of NLRP3 and caspase-1 depending on the tissue analyzed. In conclusion, our results suggest that TTC could have a potential anti-inflammatory effect by reducing IL-6 levels in tissues drastically affected by the disease. However, further research is needed to study more in depth the anti-inflammatory effect of TTC in ALS.

Type XIX collagen: a promising biomarker from the basement membranes.

Among collagen members in the collagen superfamily, type XIX collagen has raised increasing interest in relation to its structural and biological roles. Type XIX collagen is a Fibril-Associated Collagen with Interrupted Triple helices member, one main subclass of collagens in this superfamily. This collagen contains a triple helix composed of three polypeptide segments aligned in parallel and it is associated with the basement membrane zone in different tissues. The molecular structure of type XIX collagen consists of five collagenous domains, COL1 to COL5, interrupted by six non-collagenous domains, NC1 to NC6. The most relevant domain by which this collagen exerts its biological roles is NC1 domain that can be cleavage enzymatically to release matricryptins, exerting anti-tumor and anti-angiogenic effect in murine and human models of cancer. Under physiological conditions, type XIX collagen expression decreases after birth in different tissues although it is necessary to keep its basal levels, mainly in skeletal muscle and hippocampal and telencephalic interneurons in brain. Notwithstanding, in amyotrophic lateral sclerosis, altered transcript expression levels show a novel biological effect of this collagen beyond its structural role in basement membranes and its anti-tumor and anti-angiogenic properties. Type XIX collagen can exert a compensatory effect to ameliorate the disease progression under neurodegenerative conditions specific to amyotrophic lateral sclerosis in transgenic SOD1G93A mice and amyotrophic lateral sclerosis patients. This novel biological role highlights its nature as prognostic biomarker of disease progression in and as promising therapeutic target, paving the way to a more precise prognosis of amyotrophic lateral sclerosis.

Collagen XIX Alpha 1 Improves Prognosis in Amyotrophic Lateral Sclerosis.

The identification of more reliable diagnostic or prognostic biomarkers in age-related neurodegenerative diseases, such as Amyotrophic Lateral Sclerosis (ALS), is urgently needed. The objective in this study was to identify more reliable prognostic biomarkers of ALS mirroring neurodegeneration that could be of help in clinical trials. A total of 268 participants from three cohorts were included in this study. The muscle and blood cohorts were analyzed in two cross-sectional studies, while the serial blood cohort was analyzed in a longitudinal study at 6-monthly intervals. Fifteen target genes and fourteen proteins involved in muscle physiology and differentiation, metabolic processes and neuromuscular junction dismantlement were studied in the three cohorts. In the muscle biopsy cohort, the risk for a higher mortality in an ALS patient that showed high Collagen type XIX, alpha 1 (COL19A1) protein levels and a fast progression of the disease was 70.5% (P < 0.05), while in the blood cohort, this risk was 20% (P < 0.01). In the serial blood cohort, the linear mixed model analysis showed a significant association between increasing COL19A1 gene levels along disease progression and a faster progression during the follow-up period of 24 months (P < 0.05). Additionally, higher COL19A1 levels and a faster progression increased 17.9% the mortality risk (P < 0.01). We provide new evidence that COL19A1 can be considered a prognostic biomarker that could help the selection of homogeneous groups of patients for upcoming clinical trial and may be pointed out as a promising therapeutic target in ALS.

Quistes aracnoideos de localización infrecuente. Quistes extratemporales / Rare location of arachnoid cysts. Extratemporal cysts

El manejo terapéutico de los quistes aracnoideos depende, en gran medida, de su localización. Casi el 50% de los quistes aracnoideos se localizan en la fosa temporal-cisura de Silvio. En cambio, la otra mitad se reparte en localizaciones diversas, a veces excepcionales. En este trabajo describimos, bajo la denominación de «quistes aracnoideos de localización infrecuente», aquellos compuestos por las 2 hojas de membrana aracnoidea que no se encuentran localizados en la fosa temporal y que son primarios o de origen congénito

The therapeutic management of arachnoid cysts depends largely on its location. Almost 50% of arachnoid cysts are located in the temporal fossa-Sylvian fissure, whereas the other half is distributed in different locations, sometimes exceptional. Under the name of infrequent location arachnoid cysts, a description is presented of those composed of 2 sheets of arachnoid membrane, which are not located in the temporal fossa, and are primary or congenital

[Rare location of arachnoid cysts. Extratemporal cysts]. / Quistes aracnoideos de localización infrecuente. Quistes extratemporales.

The therapeutic management of arachnoid cysts depends largely on its location. Almost 50% of arachnoid cysts are located in the temporal fossa-Sylvian fissure, whereas the other half is distributed in different locations, sometimes exceptional. Under the name of infrequent location arachnoid cysts, a description is presented of those composed of 2 sheets of arachnoid membrane, which are not located in the temporal fossa, and are primary or congenital.

Comparison of industrially viable pretreatments to enhance soybean straw biodegradability.

This study explores acid and alkaline pretreatments in order to enhance soybean straw biodegradability. The effects of sulfuric acid and sodium hydroxide for different pretreatment times at 30°C and 121°C on biomass dissolution and the subsequent enzymatic hydrolysis were investigated. The highest total conversion to reducing sugars of 93.9% was attained when soybean straw was pretreated with acid (4% H2SO4, 121°C, 1 h) and subsequently subjected to the enzymatic process. However, conversion of 86.5%, were reached only with the hydrolysis of the pretreated residue using mild conditions, (0.5% NaOH, 30°C, 48 h), involving the reduction cost of the process. In addition to this, this result was dramatically decreased when pectinase was removed from the enzyme cocktail. It has been also demonstrated that the reduction of the enzyme loading to less than half allowed obtaining about 96% of the reducing sugars attained with the highest enzyme dose.

Amyotrophic lateral sclerosis: a focus on disease progression.

Since amyotrophic lateral sclerosis (ALS) was discovered and described in 1869 as a neurodegenerative disease in which motor neuron death is induced, a wide range of biomarkers have been selected to identify therapeutic targets. ALS shares altered molecular pathways with other neurodegenerative diseases, such as Alzheimer's, Huntington's, and Parkinson's diseases. However, the molecular targets that directly influence its aggressive nature remain unknown. What is the first link in the neurodegenerative chain of ALS that makes this disease so peculiar? In this review, we will discuss the progression of the disease from the viewpoint of the potential biomarkers described to date in human and animal model samples. Finally, we will consider potential therapeutic strategies for ALS treatment and future, innovative perspectives.

Alkaline and alkaline peroxide pretreatments at mild temperature to enhance enzymatic hydrolysis of rice hulls and straw.

The current study explores alkaline and alkaline peroxide pretreatments in order to achieve a method to improve saccharification of agricultural residues for ethanol production. The effects of reagent concentration and pretreatment time at 30°C and atmospheric pressure on biomass dissolution after the pretreatment and enzymatic hydrolysis of the pretreated biomass were investigated. In fact, although all pretreatments tested improved enzymatic hydrolysis of native residues, the best results were not achieved for the highest biomass loss. The maximum conversions to reducing sugars in the hydrolysis stage of 77.5% and 92.6% were obtained for rice hulls and straw pretreated by alkaline peroxide (4%, 24h) and alkaline (1%, 48 h) methods, respectively. For both pretreated residues, the reduction to more than half the recommended enzyme loading allowed obtaining more than 94% the reducing sugars attained with the recommended dose.

La grasa epicárdica se relaciona con la visceral, el síndrome metabólico y la resistencia a la insulina en mujeres menopáusicas / Epicardial Adipose Tissue Is Associated With Visceral Fat, Metabolic Syndrome, and Insulin Resistance in Menopausal Women

Introducción y objetivos El tejido adiposo epicárdico se ha asociado con diversos índices de adiposidad y resistencia a insulina. La medición de este tejido por ecocardiografía se considera una herramienta útil y accesible para valorar factores de riesgo cardiometabólico; no obstante, aún no existen suficientes estudios en mujeres posmenopáusicas, que es una etapa en la que se presenta un incremento del riesgo cardiovascular. El objetivo del estudio es analizar la relación entre las mediciones del tejido adiposo epicárdico y tejido adiposo visceral, perímetro de cintura, índice de masa corporal y resistencia a insulina en mujeres posmenopáusicas.MétodosEstudio transversal comparativo en 34 mujeres posmenopáusicas con y sin síndrome metabólico a las que se realizó ecocardiograma transtorácico y análisis de composición corporal.ResultadosSe encontró asociación positiva de las medidas de grasa epicárdica con el tejido adiposo visceral, el índice de masa corporal y el perímetro de cintura; en el surco aortoventricular derecho, las correlaciones fueron r = 0,505 (p < 0,003), r = 0,545 (p < 0,001) y r = 0,515 (p < 0,003) respectivamente. También se observó que las mujeres posmenopáusicas con síndrome metabólico presentaban aumento del tejido adiposo epicárdico en comparación con las que no tienen el síndrome (544,2 ± 122,9 frente a 363,6 ± 162,3 mm2; p = 0,03).ConclusionesEl tejido adiposo epicárdico medido por ecocardiografía se asocia con el tejido adiposo abdominal y corporal en las mujeres posmenopáusicas. Las posmenopáusicas con síndrome metabólico presentan mayor cantidad de grasa epicárdica. La medición del tejido adiposo epicárdico por ecocardiografía puede ser un método de utilidad para evaluar el riesgo cardiovascular en la posmenopausia (AU)

Introduction and objectives Epicardial adipose tissue has been associated with several obesity-related parameters and with insulin resistance. Echocardiographic assessment of this tissue is an easy and reliable marker of cardiometabolic risk. However, there are insufficient studies on the relationship between epicardial fat and insulin resistance during the postmenopausal period, when cardiovascular risk increases in women. The objective of this study was to examine the association between epicardial adipose tissue and visceral adipose tissue, waist circumference, body mass index, and insulin resistance in postmenopausal women.MethodsA cross sectional study was conducted in 34 postmenopausal women with and without metabolic syndrome. All participants underwent a transthoracic echocardiogram and body composition analysis.ResultsA positive correlation was observed between epicardial fat and visceral adipose tissue, body mass index, and waist circumference. The values of these correlations of epicardial fat thickness overlying the aorta-right ventricle were r = 0.505 (P < .003), r = 0.545 (P < .001), and r = 0.515 (P < .003), respectively. Epicardial adipose tissue was higher in postmenopausal women with metabolic syndrome than in those without this syndrome (mean [standard deviation], 544.2 [122.9] vs 363.6 [162.3] mm2; P = .03).ConclusionsEpicardial fat thickness measured by echocardiography was associated with visceral adipose tissue and other obesity parameters. Epicardial adipose tissue was higher in postmenopausal women with metabolic syndrome. Therefore, echocardiographic assessment of epicardial fat may be a simple and reliable marker of cardiovascular risk in postmenopausal women (AU)

Epicardial adipose tissue is associated with visceral fat, metabolic syndrome, and insulin resistance in menopausal women.

INTRODUCTION AND OBJECTIVES: Epicardial adipose tissue has been associated with several obesity-related parameters and with insulin resistance. Echocardiographic assessment of this tissue is an easy and reliable marker of cardiometabolic risk. However, there are insufficient studies on the relationship between epicardial fat and insulin resistance during the postmenopausal period, when cardiovascular risk increases in women. The objective of this study was to examine the association between epicardial adipose tissue and visceral adipose tissue, waist circumference, body mass index, and insulin resistance in postmenopausal women. METHODS: A cross sectional study was conducted in 34 postmenopausal women with and without metabolic syndrome. All participants underwent a transthoracic echocardiogram and body composition analysis. RESULTS: A positive correlation was observed between epicardial fat and visceral adipose tissue, body mass index, and waist circumference. The values of these correlations of epicardial fat thickness overlying the aorta-right ventricle were r = 0.505 (P < .003), r = 0.545 (P < .001), and r = 0.515 (P < .003), respectively. Epicardial adipose tissue was higher in postmenopausal women with metabolic syndrome than in those without this syndrome (mean [standard deviation], 544.2 [122.9] vs 363.6 [162.3] mm(2); P = .03). CONCLUSIONS: Epicardial fat thickness measured by echocardiography was associated with visceral adipose tissue and other obesity parameters. Epicardial adipose tissue was higher in postmenopausal women with metabolic syndrome. Therefore, echocardiographic assessment of epicardial fat may be a simple and reliable marker of cardiovascular risk in postmenopausal women.

Genetic polymorphisms in MTHFR (C677T, A1298C), MTR (A2756G) and MTRR (A66G) genes associated with pathological characteristics of prostate cancer in the Ecuadorian population.

INTRODUCTION: The methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTR) and MTR reductase (MTRR) enzymes act in the folate metabolism, which is essential in methylation and synthesis of nucleic acids. The single nucleotide polymorphisms, MTHFR C677T, A1298C, MTR A2756G and MTRR A66G, cause alteration in the homocysteine levels and reduced enzymatic activity that generates deficiency in the assimilation of folates associated with DNA damage; that is, why it is important to know if the single nucleotide polymorphisms are associated with the pathological characteristics and development of prostate cancer, through a case-control retrospective study. METHODS: DNA was extracted from 110 healthy and 104 affected men. The genotypes were determined by means of the polymerase chain reaction-restriction fragment length polymorphism and confirmed with genomic sequencing. RESULTS: We found significant association between the genotypes of the MTHFR C677T polymorphism: C/T (odds ratio [OR] = 2.2; 95% confidence interval [CI] = 1.3-3.9; P = 0.008) and C/T + T/T (OR = 2.2; 95% CI = 1.3-3.9; P = 0.009) with the risk of prostate cancer development, and a slight association with MTRR A66G. Regarding pathological characteristics, we found significant risk between the C/T + T/T genotypes and the Gleason score (7-10) of poorly differentiated carcinoma (OR = 5.2; 95% CI = 1.7-16.2; P = 0.007). On the other hand, a significant association between A1298C, A66G, and A2756G with the pathological characteristics was not found (P > 0.05). CONCLUSIONS: The MTHFR C677T polymorphism has significant effects on susceptibility to prostate cancer in Ecuadorian population, especially with the Gleason grade.

Genetic biomarkers for ALS disease in transgenic SOD1(G93A) mice.

The pathophysiological mechanisms of both familial and sporadic Amyotrophic Lateral Sclerosis (ALS) are unknown, although growing evidence suggests that skeletal muscle tissue is a primary target of ALS toxicity. Skeletal muscle biopsies were performed on transgenic SOD1(G93A) mice, a mouse model of ALS, to determine genetic biomarkers of disease longevity. Mice were anesthetized with isoflurane, and three biopsy samples were obtained per animal at the three main stages of the disease. Transcriptional expression levels of seventeen genes, Ankrd1, Calm1, Col19a1, Fbxo32, Gsr, Impa1, Mef2c, Mt2, Myf5, Myod1, Myog, Nnt, Nogo A, Pax7, Rrad, Sln and Snx10, were tested in each muscle biopsy sample. Total RNA was extracted using TRIzol Reagent according to the manufacturer's protocol, and variations in gene expression were assayed by real-time PCR for all of the samples. The Pearson correlation coefficient was used to determine the linear correlation between transcriptional expression levels throughout disease progression and longevity. Consistent with the results obtained from total skeletal muscle of transgenic SOD1(G93A) mice and 74-day-old denervated mice, five genes (Mef2c, Gsr, Col19a1, Calm1 and Snx10) could be considered potential genetic biomarkers of longevity in transgenic SOD1(G93A) mice. These results are important because they may lead to the exploration of previously unexamined tissues in the search for new disease biomarkers and even to the application of these findings in human studies.

Sex, fiber-type, and age dependent in vitro proliferation of mouse muscle satellite cells.

During postnatal growth and after muscle injury, satellite cells proliferate and differentiate into myotubes to form and repair musculature. Comparison of studies on satellite cell proliferation and differentiation characteristics is confounded by the heterogeneity of the experimental conditions used. To examine the influence of sex, age, and fiber-type origin on in vitro properties of satellite cells derived from postnatal muscles, fast extensor digitorum longus (EDL) and slow soleus (SOL) muscles were extracted from male and female mice of 1 week to 3 months of age. Myoblast proliferation and myogenic regulatory factor (MRF) expression was measured from cultures of freshly isolated satellite cells. Higher proliferation rate and elevated Myod1 expression was found in male EDL and SOL derived cells compared with females at age of 40, 60, and 120 days, whereas inverse tendency for cell proliferation was apparent in EDL of juvenile (7-day-old) pups. Myogenin and Mrf4 transcripts were generally elevated in males of 40 and 60 days of age and in female EDL of juveniles. However, these differentiation markers did not significantly correlate with proliferation rate at all ages. Pax7, whose overexpression can block myogenesis, was up-regulated especially in 40-day-old females where MRF expression was low. These results indicate that gender, postnatal age, and muscle fiber origin affect proliferation and muscle transcription factor expression in vitro. The results also support the view that satellite cells originating from slow and fast muscles are intrinsically different and warrant further studies on the effect of cell origin for therapeutic approaches.

Lack of a synergistic effect of a non-viral ALS gene therapy based on BDNF and a TTC fusion molecule.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is one of the most devastating neurodegenerative diseases. Neurotrophic factors have been widely tested to counteract neurodegenerative conditions, despite their unspecific neuronal access. The non-toxic C-terminal fragment of the tetanus toxin (TTC) heavy chain has been studied not only as a carrier molecule to the CNS but also as a neuroprotective agent. Because the neurotrophic effects of BDNF have been demonstrated in vitro and in vivo, the question addressed in this work is whether a fusion molecule of BDNF-TTC may have a synergistic effect and enhance the neuroprotective properties of TTC alone in a mouse model of ALS. METHODS: Recombinant plasmid constructs (pCMV-TTC and pCMV-BDNF-TTC) were injected into the quadriceps femoris and triceps brachialis muscles of SOD1(G93A) transgenic mice at 8 weeks of age. The hanging wire and rotarod tests were performed to assess motor coordination, strength and balance. Electrophysiological tests, morphological assays of spinal cord sections of L2 and L4 segments, and gene and protein expression analyses were performed. The Kaplan-Meier survival analysis test was used for comparisons of survival. Multiple comparisons of data were analyzed using a one-way analysis of variance (ANOVA). RESULTS: Treatment with the fusion-molecule BDNF-TTC and with TTC alone significantly delayed the onset of symptoms and functional deficits of SOD1(G93A) mice. Muscle innervation was partially preserved with these treatments, and the number of surviving motoneurons in L2 spinal cord segment was increased particularly by the fusion protein induction. Inhibition of pro-apoptotic protein targets (caspase-3 and Bax) and significant phosphorylation of Akt and ERK were also found in the spinal cord of treated mice. CONCLUSIONS: Significant improvements in behavioral and electrophysiological results, motoneuron survival and anti-apoptotic/survival-activated pathways were observed with BDNF-TTC treatment. However, no synergistic effect was found for this fusion molecule. Although BDNF in the fusion molecule is capable of activating autocrine and neuroprotective pathways, TTC treatment alone yielded similar neuroprotection. Therefore, an accurate study of the neuroprotective effects of TTC fusion molecules should be performed to obtain a better understanding of its effects.

Altered expression of myogenic regulatory factors in the mouse model of amyotrophic lateral sclerosis.

BACKGROUND: In the superoxide dismutase 1 (SOD1)-G93A mouse model of amyotrophic lateral sclerosis (ALS), skeletal muscle is a key target of mutant SOD1 toxicity. However, the expression of factors that control the regenerative potential of the muscle is unknown in this model. OBJECTIVE: To characterize the expression of satellite cell marker Pax7 and myogenic regulatory factors (MRF) in skeletal muscle of SOD1-G93A mice at different stages of the disease. METHODS: The expressions of Pax7, Myod1, Myf5 and myogenin (Myog) were determined by quantitative real-time PCR and by Western blotting from the grouped gastrocnemius, quadriceps and soleus muscles of SOD1-G93A mice at presymptomatic, symptomatic and terminal stages of the disease, and from surgically denervated wild-type gastrocnemius muscles. RESULTS: Pax7 mRNA and MYF5 protein were upregulated in presymptomatic mice, coinciding with increased muscle damage marker Rrad and chemokine Ccl5. All MRF transcripts and most proteins (excluding MYOG) were increased, starting from 3 months of age, simultaneously with increased expression of denervation marker Chrna1. However, in the terminal stage, no protein increase was evident for Pax7 or any of the MRF despite the increased mRNA levels. The transcripts for chemokine Ccl2 and chemokine receptor Cxcr4 were increased starting from the onset of symptoms. CONCLUSIONS: The characterization of Pax7 and MRF in SOD1-G93A mice reveals a progressive induction of the myogenic program at the RNA level, but a blunted protein level response at late stages of the disease. Altered posttranscriptional and posttranslational mechanisms likely to operate, as well as the potential role of chemokine signaling in mutant SOD1 muscle, are discussed.