TEMPO-conjugated tobacco mosaic virus as a magnetic resonance imaging contrast agent for detection of superoxide production in the inflamed liver.

Superoxide, an anionic dioxygen molecule, plays a crucial role in redox regulation within the body but is implicated in various pathological conditions when produced excessively. Efforts to develop superoxide detection strategies have led to the exploration of organic-based contrast agents for magnetic resonance imaging (MRI). This study compares the effectiveness of two such agents, nTMV-TEMPO and kTMV-TEMPO, for detecting superoxide in a mouse liver model with lipopolysaccharide (LPS)-induced inflammation. The study demonstrates that kTMV-TEMPO, with a strategically positioned lysine residue for TEMPO attachment, outperforms nTMV-TEMPO as an MRI contrast agent. The enhanced sensitivity of kTMV-TEMPO is attributed to its more exposed TEMPO attachment site, facilitating stronger interactions with water protons and superoxide radicals. EPR kinetics experiments confirm kTMV-TEMPO's faster oxidation and reduction rates, making it a promising sensor for superoxide in inflamed liver tissue. In vivo experiments using healthy and LPS-induced inflamed mice reveal that reduced kTMV-TEMPO remains MRI-inactive in healthy mice but becomes MRI-active in inflamed livers. The contrast enhancement in inflamed livers is substantial, validating the potential of kTMV-TEMPO for detecting superoxide in vivo. This research underscores the importance of optimizing contrast agents for in vivo imaging applications. The enhanced sensitivity and biocompatibility of kTMV-TEMPO make it a promising candidate for further studies in the realm of medical imaging, particularly in the context of monitoring oxidative stress-related diseases.

Preoperative imaging of glioblastoma patients using hyperpolarized 13C pyruvate: Potential role in clinical decision making.

BACKGROUND: Glioblastoma remains incurable despite treatment with surgery, radiation therapy, and cytotoxic chemotherapy, prompting the search for a metabolic pathway unique to glioblastoma cells.13C MR spectroscopic imaging with hyperpolarized pyruvate can demonstrate alterations in pyruvate metabolism in these tumors. METHODS: Three patients with diagnostic MRI suggestive of a glioblastoma were scanned at 3 T 1-2 days prior to tumor resection using a 13C/1H dual-frequency RF coil and a 13C/1H-integrated MR protocol, which consists of a series of 1H MR sequences (T2 FLAIR, arterial spin labeling and contrast-enhanced [CE] T1) and 13C spectroscopic imaging with hyperpolarized [1-13C]pyruvate. Dynamic spiral chemical shift imaging was used for 13C data acquisition. Surgical navigation was used to correlate the locations of tissue samples submitted for histology with the changes seen on the diagnostic MR scans and the 13C spectroscopic images. RESULTS: Each tumor was histologically confirmed to be a WHO grade IV glioblastoma with isocitrate dehydrogenase wild type. Total hyperpolarized 13C signals detected near the tumor mass reflected altered tissue perfusion near the tumor. For each tumor, a hyperintense [1-13C]lactate signal was detected both within CE and T2-FLAIR regions on the 1H diagnostic images (P = .008). [13C]bicarbonate signal was maintained or decreased in the lesion but the observation was not significant (P = .3). CONCLUSIONS: Prior to surgical resection, 13C MR spectroscopic imaging with hyperpolarized pyruvate reveals increased lactate production in regions of histologically confirmed glioblastoma.

Diseño de un registro de fibrilación auricular y riesgo embólico en México: CARMEN-AF / Design of an atrial fibrillation and embolic risk registry in Mexico: CARMEN-AF

Resumen: Objetivo: La fibrilación auricular (FA) es una de las arritmias más comunes, y su prevalencia aumenta con la edad. Se asocia con alto riesgo de embolia cerebral. La prevención de dichas tromboembolias se realiza mediante anticoagulantes orales, que en nuestro país parecen estar subutilizados. El Registro CARMEN-AF tiene como objetivo primario determinar cuál es el estado actual de la tromboprofilaxis de la FA no valvular en México. Como objetivo secundario pretende conocer la morbimortalidad asociada a la FA no valvular en por lo menos un año de seguimiento. Métodos: El Registro CARMEN-AF es un estudio observacional, longitudinal, multicéntrico y nacional sobre el empleo de los anticoagulantes orales en pacientes con FA no-valvular que pretende la inclusión de pacientes mayores de 18 años de edad diagnosticados con FA no valvular durante los últimos 6 meses y con al menos un factor de riesgo para desarrollar una tromboembolia de acuerdo con la escala de CHA2DS2-Vasc. Serán recolectados datos demográficos y clínicos en las visitas clínicas habituales a lo largo de un seguimiento de 2 años. El reclutamiento comenzó el 19 de septiembre de 2014 y se prevé la inclusión del último paciente el 18 de septiembre de 2016. Se estima la inclusión de 1,200 pacientes dada la incidencia de FA reportada a nivel mundial y tomando en consideración la población mexicana total. Conclusiones: El registro de FA y riesgo embólico en México (CARMEN-AF) permitirá conocer el estado actual de la tromboprofilaxis en pacientes con FA no valvular y permitirá obtener una panorámica del cumplimiento de las guías nacionales e internacionales de práctica clínica en esta materia.

Abstract: Objective: Atrial fibrillation (AF) is one of the most common arrhythmias, and its prevalence increase with age. It is associated with high risk of stroke. The prevention of such thromboembolism is done with oral anticoagulants, which in our country seem to be underused. CARMEN-AF registry aims primarily to determine the current status of thromboprophylaxis of non-valvular AF in Mexico. A secondary objective is to know the morbidity and mortality associated with non-valvular AF in at least one year of follow-up. Methods: CARMEN-AF registry is an observational, longitudinal, multicenter, and national survey about the use of oral anticoagulants in patients with non-valvular AF. Patients 18 years old or older, diagnosed with AF during the last 6 months, and with at least one risk factor of thromboembolism based in the CHA2DS2-Vasc score are being selected. Demographic and clinical data will be collected during the visits to their usual clinic with a follow-up of 2 years. The recruitment began on September 19, 2014, and the inclusion of the last patient is expected on September 18, 2016. According to the reported incidence of AF globally and taking into account the total Mexican population, the inclusion of 1,200 patients is estimated. Conclusions: The Atrial Fibrillation and Embolic Risk Registry (CARMEN-AF) will reveal the current status of thromboprophylaxis in patients with non-valvular AF, and will allow to get an overview of the national and international clinical practice guidelines accomplishment in this area.

Genetic factors conferring an increased susceptibility to develop Crohn's disease also influence disease phenotype: results from the IBDchip European Project.

OBJECTIVE: Through genome-wide association scans and meta-analyses thereof, over 70 genetic loci (Crohn's disease (CD) single nucleotide polymorphisms (SNPs)) are significantly associated with CD. We aimed to investigate the influence of CD-SNPs and basic patient characteristics on CD clinical course, and develop statistical models to predict CD clinical course. DESIGN: This retrospective study included 1528 patients with CD with more than 10 years of follow-up from eight European referral hospitals. CD outcomes of interest were ileal (L1), colonic (L2) and ileocolonic disease location (L3); stenosing (B2) or penetrating behaviour (B3); perianal disease; extraintestinal manifestations; and bowel resection. A complicated disease course was defined as stenosing or penetrating behaviour, perianal disease and/or bowel resection. Association between CD-SNPs or patient characteristics and specified outcomes was studied. RESULTS: Several CD-SNPs and clinical characteristics were statistically associated with outcomes of interest. The NOD2 gene was the most important genetic factor, being an independent predictive factor for ileal location (p=2.02 × 10(-06), OR=1.90), stenosing (p=3.16 × 10(-06), OR=1.82) and penetrating (p=1.26 × 10(-02), OR=1.25) CD behaviours, and need for surgery (p=2.28 × e-05, OR=1.73), and as such was also the strongest factor associated with a complicated disease course (p=6.86 × 10(-06), OR=2.96). Immunomodulator (azathioprine/6-mercaptopurine and methotrexate) use within 3 years after diagnosis led to a reduction in bowel stenoses (p=1.48 × 10(-06), OR=0.35) and surgical rate (p=1.71 × 10(-07), OR=0.34). Association between each outcome and genetic scores, created using significant SNPs in the univariate analysis, revealed large differences in the probability of developing fistulising disease (IL23R, LOC441108, PRDM1, NOD2; p=9.64e-4, HR=1.43), need for surgery (IRGM, TNFSF15, C13ORF31, NOD2; p=7.12 × 10(-03), HR=1.35), and stenosing disease (NOD2, JAK2, ATG16L1; p=3.01 × 10(-02), HR=1.29) among patients with low and high score. CONCLUSIONS: This large multicentre cohort study has found several genetic and clinical factors influencing the clinical course of CD. NOD2 and early immunomodulator use are the clinically most meaningful predictors for its clinical course.

Azurin as a protein scaffold for a low-coordinate nonheme iron site with a small-molecule binding pocket.

The apoprotein of Pseudomonas aeruginosa azurin binds iron(II) to give a 1:1 complex, which has been characterized by electronic absorption, Mössbauer, and NMR spectroscopies, as well as X-ray crystallography and quantum-chemical computations. Despite potential competition by water and other coordinating residues, iron(II) binds tightly to the low-coordinate site. The iron(II) complex does not react with chemical redox agents to undergo oxidation or reduction. Spectroscopically calibrated quantum-chemical computations show that the complex has high-spin iron(II) in a pseudotetrahedral coordination environment, which features interactions with side chains of two histidines and a cysteine as well as the C═O of Gly45. In the (5)A(1) ground state, the d(z(2)) orbital is doubly occupied. Mutation of Met121 to Ala leaves the metal site in a similar environment but creates a pocket for reversible binding of small anions to the iron(II) center. Specifically, azide forms a high-spin iron(II) complex and cyanide forms a low-spin iron(II) complex.

Effects of diabetes and obesity on vascular reactivity, inflammatory cytokines, and growth factors.

We examined the influences of obesity and diabetes on endothelium-dependent and -independent vasodilation, inflammatory cytokines, and growth factors. We included 258 subjects, age 21-80 years in four groups matched for age and gender: 40 healthy nonobese (BMI <30 kg·m(-2)) nondiabetic subjects, 76 nonobese diabetic patients, 37 obese (BMI >30) nondiabetic subjects, and 105 obese (BMI >30) diabetic patients. The flow-mediated dilation (FMD, endothelium-dependent) and nitroglycerin-induced dilation (NID, endothelium-independent) in the brachial artery, the vascular reactivity at the forearm skin and serum growth factors and inflammatory cytokines were measured. FMD was reduced in the nonobese diabetic patients, obese nondiabetic controls, and obese diabetic patients (P < 0.0001). NID was different among all four groups, being highest in the obese nondiabetic subjects and lowest in the obese diabetic patients (P < 0.0001). The resting skin forearm blood flow was reduced in the obese nondiabetic subjects (P < 0.01). Vascular endothelial growth factor (VEGF) was higher in the obese nondiabetic subjects (P < 0.05), tumor necrosis factor-α was higher in the obese diabetic patients (P < 0.0001) and C-reactive protein was higher in both the obese nondiabetic and diabetic subjects (P < 0.0001). Soluble intercellular adhesion molecule-1 was elevated in the two diabetic groups and the obese nondiabetic subjects (P < 0.05). We conclude that diabetes and obesity affect equally the endothelial cell function but the smooth muscle cell function is affected only by diabetes. In addition, the above findings may be related to differences that were observed in the growth factors and inflammatory cytokines.

CDH1 gene polymorphisms, smoking, Helicobacter pylori infection and the risk of gastric cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC-EURGAST).

Despite declining incidence rates, gastric cancer (GC) is a major cause of death worldwide. E-Cadherin is an adhesion molecule that is thought to be involved in GC. Germline mutations in the E-Cadherin gene (CDH1) have been identified in hereditary diffuse GC. Also, a promoter polymorphism at position -160 C/A has been suggested to lead to transcriptional down regulation and has been shown to affect GC risk in some studies. However, very little information exists on the GC risk association of other CDH1 polymorphisms and it is unclear whether any associations may be different by GC anatomical sites or histological types. Thus, a case-control study (cases=245/controls=950) nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort was conducted to assess the GC risk association of eight CDH1 gene polymorphisms. None of the CDH1 polymorphisms or haplotypes analysed were associated with GC risk and no differences of effect were observed by Helicobacter pylori infection status. However, three CDH1 polymorphisms in the same haplotype block, including the CDH1-160C/A, interacted with smoking to increase GC risk in smokers but not in never smokers. These findings should be confirmed in larger independent studies.

Schedule shifts, cancer and longevity: good, bad or indifferent?

Prompted by a recent report of the possible carcinogenic effect of shiftwork focusing on the disruption of circadian rhythms, we review studies involving shifts in schedule implemented at varying intervals in unicells, insects and mammals, including humans. Results indicate the desirability to account for a broader-than-circadian view. They also suggest the possibility of optimizing schedule shifts by selecting intervals between consecutive shifts associated with potential side-effects such as an increase in cancer risk. Toward this goal, marker rhythmometry is most desirable. The monitoring of blood pressure and heart rate present the added benefit of assessing cardiovascular disease risks resulting not only from an elevated blood pressure but also from abnormal variability in blood pressure and/or heart rate of normotensive as well as hypertensive subjects.

Relationship between clinical features of Crohn's disease and the risk of developing extraintestinal manifestations.

OBJECTIVES: Crohn's disease is frequently associated with extraintestinal manifestations. The aim of this study was to evaluate the degree of association between the development of extraintestinal manifestations, the clinical forms of Crohn's disease according to the Vienna Classification and to the presence of several potential risk factors of the disease. METHODS: One hundred and seventy-three consecutive Crohn's disease patients were studied. Sex, smoking habits, previous Crohn's disease-related surgery, family history of Crohn's disease, steroid dependency, steroid resistance and the presence of at least one mutant allele in any of the three considered variants of CARD15 gene were considered as potential risk factors. The Vienna Classification was applied, and the presence of extraintestinal manifestations was evaluated. RESULTS: A total of 61 (35.3%) patients developed extraintestinal manifestations. They were more frequently seen in women than in men (41.1 vs. 26.7%), (odds ratio 1.92, 95% confidence interval: 0.99-3.70; P=0.05) and in steroid-dependent patients than in steroid responders (61.1 vs. 28.5%), (odds ratio 3.94, 95% confidence interval: 1.83-8.49; P<0.01). No relationship was found in general between the extraintestinal manifestations of Crohn's disease and smoking habits, previous Crohn's disease-related surgery, a family history of Crohn's disease, steroid resistance and CARD15 mutations. Such relationships were, however, detected for some individual extraintestinal manifestations as between both smoking habits (odds ratio 9.09, 95% confidence interval: 1.15-71.66; P<0.05) and the G908R CARD15 mutation (odds ratio 4.76, 95% confidence interval: 1.11-20.43; P<0.05), respectively, and erythema nodosum. Patients with any colonic involvement of Crohn's disease (L2+L3) suffered from extraintestinal manifestations of the disease more frequently than patients without colonic involvement (42.7 vs. 25.9%, respectively; odds ratio 2.12, 95% confidence interval: 1.10-4.07; P<0.05). CONCLUSIONS: Female gender, steroid-dependency and colonic involvement are associated with the risk of developing extraintestinal manifestations of Crohn's disease.

Autoantibodies and histogenesis of celiac disease.

OBJECTIVE: Autoantibodies are used as markers for celiac disease (CD) identifying patients with mucosal lesions. The purpose of this study was to evaluate the sensitivity and role of the autoantibodies such as IgA antiendomysium (EMA), IgA antigliadin (AGA) and the IgA antitissue transglutaminase (tTGA) in histogenesis of celiac disease. METHODS: Seventy-nine cases including 30 untreated celiacs, 5 celiacs on gluten-free diet (GFD), 41 first degree relatives and 3 non-relatives suspected for CD were investigated. Three untreated celiacs with IgA deficiency were excluded from this study group. IgA antibodies to tTGA were determined by ELISA, as described before. Twelve of 41 relatives and 2 cases of non relatives suspected with positive serology underwent a small intestinal biopsy. Results were correlated with the degrees of abnormality of the intestinal mucosa in patients with CD. Intestinal biopsies obtained from study population were evaluated for histological quantification. RESULTS: Celiacs and suspected cases with positive EMA/AGA and or tTGA showed shorter villi (p < 0.007) and/or a higher number of intraepithelial lymphocytes (IEL) (p < 0.035). The sensitivity of serology (EMA, AGA, tTGA) in patients with Marsh IIIc was 100%. However, in patients with Marsh IIIa the sensitivity for EMA, AGA, and tTGA was 40%, 50% and 20% respectively. CONCLUSIONS: The appearance of antibodies is related to the degree of mucosal infiltration by IELs. Although tTGA, like EMA provide a highly sensitive parameter for the detection of celiacs with severe mucosal damage, it appears to be less sensitive (even less than AGA) in celiac patients with milder histopathological abnormalities. However, it should be recognized that the substantial part of the celiac population present with these milder forms of mucosal abnormalities. Using tTGA as a single test in screening may result in missing up to 60-70% of celiacs with mild mucosal abnormalities. Combination with other screening tests (at least with AGA) is essential and strongly recommended

Perfiles de glucosa e insulina en pacientes con hepatitis crónica por virus C / Glucose and insulin profiles on patients with chronic C hepatitis

Con objeto de estudiar el comportamiento de los perfiles de glucosa e insulina en pacientes con hepatitis crónica por virus C (HCV), se incluyeron once pacientes con edad promedio de 47.5 años e índice de masa corporal de 23.8 por ciento 1.4. Cinco de ellos eran diabéticos. Su diabetes apareció años después de la hepatitis. El grupo control estuvo compuesto por 12 sujetos sanos con edad promedio de 42.8 años e índice de masa corporal de 24.1 ñ 1.2. Los pacientes tuvieron hepatitis crónica con diferentes grados de daño hepático, pero sin cirrosis. Las cifras de glucosa en ayunas fueron 119.9 ñ 43.4 mg/dL para el grupo de pacientes y 91.9 ñ 3.6 mg/dL para el control. Los niveles de insulina de ayunas fueron 28.1 ñ 17 µU/mL para el grupo de pacientes y 12.9 ñ 3.9 µU/mL para el control. Los valores posprandiales de insulina fueron 38.5 ñ 38 µU/mL para el grupo de pacientes y 51.04 ñ 27 µU/mL para el control. Los valores poprandiales de glucosa fueron 146.9 ñ 118 mg/dL para el grupo de pacientes y 104 ñ 15 mg/mL para el control. En cuanto a la glucosa y a la insulina, el grupo de pacientes no mostró diferencias significativas cuando sus valores de ayuno se compararon versus los posprandiales, contrario a lo que sucedió en el control (p < 0.01 y p< 0.005). Se sugiere que en pacientes con HCV se efectúen periódicamente mediciones de glucemia de ayuno y posprandiales para detectar oportunamente alteraciones de hiperglucemia

Diferencias entre los ácidos ribonucleicos mensajeros de hígado normal y de hepatoma de Novikoff / Differences between the messenger ribonucleic acids of the normal liver and Novikoff's hepatoma

En la activación de varios genes en algunas células cancerosas aparentemente se requiere que se desencadene una cascada de eventos, que trae como consecuencia la transcripción de diversos genes; al mismo tiempo, otros genes son reprimidos. El propósito de este trabajo fue investigar si existen diferencias en la transcripción del ácido ribonucleico mensajero (mRNA) del hígado normal y del hepatoma de Novikoff. En todos los experimentos se utilizaron ratas macho adultas Sprague Dawley. La extracción del RNA total de bazo, hígado y células del hepatoma de Novikoff se llevó a cabo con el método de Schueltz y la separación del mRNA se realizó utilizando una columna de celulosa-ácido oligotimidílico, de acuerdo a lo señalado por Aviv y Leder. La cuantificación del mRNA mostró que las células del hepatoma de Novikoff tienen el doble de esta macromolécula comparadas con el hígado normal de rata

Bioterapia del hepatoma de Novikoff con DNA politimidílico / Biotherapy of Novikoff's hepatoma with thymidilic DNA

Con el propósito de investigar una nueva forma de bioterapia nosotros exploramos el tratamiento del hepatoma de Novikoff con DNA que sintetiza RNA mensajero (mRNA). Para trasmitir permanentemente esta información en las células de hepatoma de Novikoff, se decidió usar DNA politimidílico (DNA poli T). La extracción de DNA poli T y de mRNA de hígado y de bazo de ratas normales o inmunizadas con células de hepatoma de Novikoff no viables se llevó a cabo por medio de cromatografía de afinidad con una columna de celulosa-ácido oliodenílico y de celulosa-ácido oligotimidílico, respectivamente. Las células de hepatoma de Novikoff viables fueron inoculadas intraperitonealmente en roedores machos Sprague Dawley, después de haber sido incubadas 30 minutos a 37 ºC con: a) solución salina, b) solución salina con 100 µgde mRNA de hígado normal de rata, c) 100 µg de mRNA de bazo normal de rata, d) 100 µg de mRNA de bazo de ratas inmunizadas con células no viables de hepatoma de Novikoff, e) 100 µg de DNA poli T de hígado normal de rata y f) 100 µg de DNA poli T de bazo normal de rata. La supervivencia de las ratas se evaluó hasta 200 días después de la inoculación de las células tumorales. El análisis de varianza mostró una supervivencia más larga, estadísticamente significativa, de las ratas inoculadas con células de hepatoma de Novikoff tratadas con DNA poli T bazo normal de rata. Estos resultados sugieren que la administración de DNA poli T podría ser usada como poligenoterapia del cáncer y que su efectividad podría ser mayor en las células neoplásicas en suspensión y probablemente la incorporación del DNA poli T en el material genética sería más fácil. Es aconsejable la administración de estas macromoléculas, como una forma de poligenoterapia en neoplasias experimentales, para evaluar su posible utilización en el ser humano

Diabetes mellitus, resistencia a la insulina y enfermedades crónicas del hígado / Diabetes mellitus, resistance to insulin and chronic diseases of the liver

Se analizan los cambios que ocurren en el metabolismo de la glucosa en pacientes con hepatopatías crónicas. La sensibilidad a la insulina está disminuida en los pacientes con cirrosis hepática, incluso antes de que la intolerancia a la glucosa se haga manifiesta. La resistencia a la insulina reside en el músculo y mayormente resulta de un defecto en la síntesis del glucógeno. La diabetes mellitus en los pacientes con cirrosis y resistencia a la insulina es el resultado de un defecto progresivo en la secreción de insulina con el desarrollo de resistencia a la insulina por el hígado, lo que conduce a la hiperglucemia de ayuno.

Variaciones circadianas de algunas enzimas y hormonas en el cuerpo humano / Circadian rhytms of some ensymes and hormones in the human body

Desde hace algunos años, se ha estudiado con gran interés la asociación de los ritmos circadianos con la acción metabólica de las enzimas y otras moléculas. En este trabajo, se destacan algunos estudios que se han realizado en humanos para demostrar los ritmos circadianos de algunas enzimas y hormonas que son necesarias para el metabolismo, aunque también se hace referencia a las observaciones realizadas en modelos experimentales. El conocimiento de los ritmos circadianos de las enzimas y hormonas constituye una herramienta útil para la administración oportuna de medicamentos en el tratamiento de enfermedades.

Conceptos básicos en cronobiomedicina / Basic concepts in chronobiomedicine

Los seres vivientes se caracterizan por exhibir fenómenos cíclicos que les permiten interactuar con ellos mismos y con otros seres. Los principales objetivos de la cronobiología son la cuantificación de la variabilidad de estos fenómenos cíclicos, así como de los fenómenos rítmicos que les permiten sus interacciones; esto se lleva a cabo por medio de la determinación estadística (cronas) de la estructura temporal (cronoma) de cada organismo. La aplicación y desarrollo de estudios cronobiológicos en el ser humano constituyen la cronobiomedicina.