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PURPOSE: The aim of this study was to investigate the differences in early (EOAD) and late (LOAD) onset of Alzheimer´s disease, as well as glucose uptake, regional cerebral blood flow (R1), amyloid depositions, and functional brain connectivity between normal young (YC) and Old Controls (OC). METHODOLOGY: The study included 22 YC (37 ± 5 y), 22 OC (73 ± 5.9 y), 18 patients with EOAD (63 ± 9.5 y), and 18 with LOAD (70.6 ± 7.1 y). Patients underwent FDG and PIB PET/CT. R1 images were obtained from the compartmental analysis of the dynamic PIB acquisitions. Images were analyzed by a voxel-wise and a VOI-based approach. Functional connectivity was studied from the R1 and glucose uptake images. RESULTS: OC had a significant reduction of R1 and glucose uptake compared to YC, predominantly at the dorsolateral and mesial frontal cortex. EOAD and LOAD vs. OC showed a decreased R1 and glucose uptake at the posterior parietal cortex, precuneus, and posterior cingulum. EOAD vs. LOAD showed a reduction in glucose uptake and R1 at the occipital and parietal cortex and an increased at the mesial frontal and temporal cortex. There was a mild increase in an amyloid deposition at the frontal cortex in LOAD vs. EOAD. YC presented higher connectivity than OC in R1 but lower connectivity considering glucose uptake. Moreover, EOAD and LOAD showed a decreased connectivity compared to controls that were more pronounced in glucose uptake than R1. CONCLUSION: Our results demonstrated differences in amyloid deposition and functional imaging between groups and a differential pattern of functional connectivity in R1 and glucose uptake in each clinical condition. These findings provide new insights into the pathophysiological processes of AD and may have an impact on patient diagnostic evaluation.

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Small ruminant lentiviruses (SRLV) cause an incurable multiorganic disease widely spread in sheep and goats that disturbs animal welfare and production. In the absence of a vaccine, control measures have been traditionally based on early diagnosis and breeding with virus-inactivated colostrum with segregation of seropositive animals. However, antigenic heterogeneity, poor antibody production due to low viral load, and single strain design of most available ELISA, pose a threat to SRLV diagnosis. Genome-wide association studies have described TMEM154 E35K polymorphism as a good genetic marker for selection of resistant animals in some American and European breeds. In this study, a multitargeted serological and virological screening of more than 500 animals from four different breeds (latxa, raza Navarra, assaf, and churra) attending to SRLV infection status was performed. Then, animals were genotyped to characterize TMEM154 E35K polymorphism. ELISA procedures, individually considered, only identified a proportion of the seropositive animals, and PCR detected a fraction of seronegative animals, globally offering different animal classifications according to SRLV infection status. TMEM154 allele frequency differed substantially among breeds and a positive association between seroprevalence and TMEM154 genotype was found only in one breed. Selection based on TMEM154 may be suitable for specific ovine breeds or SRLV strains, however generalization to the whole SRLV genetic spectrum, ovine breeds, or epidemiological situation may need further validation.

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Resumen En el Ecuador ha habido un importante incremento en el número de publicaciones sobre Esclerosis Múltiple (EM) en los últimos años. Este interés por conocer el comportamiento clínico y epidemiológico de la enfermedad nos ha permitido establecer semejanzas y diferencias con otras cohortes de pacientes con EM que provienen de regiones en donde la prevalencia de la enfermedad es alta. El Ecuador sigue siendo un país de baja prevalencia, los estudios han demostrado que la misma fluctúa entre 3 a 5 casos por 100.000 habitantes. El comportamiento epidemiológico es muy similar a la de cohortes europeas por ejemplo el sexo femenino es el principalmente afectado. Sin embargo, el comportamiento clínico difiere en lo que respecta a deterioro cognitivo, fatiga siendo éstos menos frecuentes. Aún se desconoce el impacto de la vitamina D en nuestros pacientes debido a que, solo un estudio ha sido llevado a cabo. Al parecer, existe una alta prevalencia de deficiencia e insuficiencia de vitamina D en los pacientes ecuatorianos pero no se traduce en un incremento de prevalencia o discapacidad como ocurre en poblaciones europeas. A pesar de que tenemos una mejor comprensión de la enfermedad en el país, más estudios son necesarios y es imperativo incluir a todos los pacientes ecuatorianos con esclerosis múltiple con el fin de mejorar nuestro conocimiento sobre el comportamiento de esta patología en nuestra región.

Abstract In recent years, the number of publications on Multiple Sclerosis (MS) from Ecuador has seen a significant increase. As a result, the research on the clinical and epidemiological behaviour of the disease has allowed us to make comparisons with other cohorts of patients with MS that come from regions where the prevalence of the disease is high. Nevertheless, Ecuador is still a country in which the prevalence of MS is low with a prevalence that fluctuates between 3 to 5 cases per 100,000 inhabitants. The epidemiological behaviour of MS is very similar to that of european cohorts, for example female patients are the most affected. However, the clinical behaviour of multiple sclerosis differs in terms of cognitive impairment and fatigue being less frequent. The impact of vitamin D on patients with MS is still unknown as only one study has been carried out. This study show that there is a high prevalence of vitamin D deficiency and insufficiency in ecuadorian patients, but this does not translate into an increase in prevalence or disability as it does in european populations. Although we have a better understanding of the disease in the country, more studies are necessary, and it is imperative that all ecuadorian patients with MS be included in future studies in order to improve our knowledge about the behaviour of this disease in our region.

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Following publication of the original article [1], Andrés Damián Ortega Heredia requested that his name be corrected from.

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BACKGROUND: Creutzfeldt-Jakob disease is a rare and fatal neurodegenerative disorder that affects mammals and humans. The prevalence of this disease in the United States is 0.5 to 1 per million inhabitants. So far in Ecuador, we do not know what the prevalence or incidence is, and only one case report has been written. CASE PRESENTATION: We present a case series of Creutzfeldt-Jakob disease in a third-level hospital in Quito. The average age of symptom onset in our patients was 58.8 years. The male to female ratio was 1:1. Two patients began with cognitive/behavioral symptoms, while 4 patients began with focal neurological signs; 1 case with ataxia, 2 with gait disorders and 1 with vertigo and headache. All of the patients had the clinical features established by the World Health Organization. In addition, the entire cohort was positive for the 14-3-3 protein in cerebrospinal fluid, and had high signal abnormalities in caudate and putamen nucleus in DWI and FLAIR IRM. Only in one case, did we reach a definitive diagnosis through a pathological study. All other cases had a probable diagnosis. In this series of cases, 6 out of 6 patients died. The average time from the onset of the symptoms to death in this cohort was 13 months. CONCLUSION: This is the first report of a series of cases of Creutzfeldt-Jakob disease in Quito. Although definitive diagnosis must be histopathological, there are ancillary tests currently available that have allowed us to obtain a diagnosis of the disease.

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The transmission frequency of small ruminant lentiviruses (SRLVs) through the placenta is controversial and may be associated with breed susceptibility. In Mexico, SRLV infections in sheep have been poorly studied. This work explores the presence of antibodies and proviral DNA in Mexican Pelibuey sheep. Enzyme-linked immunosorbent assays (ELISAs; three commercial kits and two on the basis of synthetic peptides) and polymerase chain reaction (PCR; amplifying the long terminal repeat and gag segments) were performed to diagnose SRLV infection in 25 adult Pelibuey ewes with an average age of 2.5 years and 32 fetuses with gestational ages ranging from 40 to 90 days without clinical signs of SRLV. Two of the three commercial ELISAs and the synthetic peptide-based ones were positive for SRLV antibody detection in 28% and 24% of the ewes, respectively, whereas none of the fetuses were positive by any of the ELISAs. By PCR, 31% of the ewes and, interestingly, two fetuses were positive. Characteristic SRLV lesions were not found in the fetal and/or ewe tissues, including those with positive PCR results. These findings demonstrate the susceptibility of Pelibuey sheep to SRLV infection and the low transmission frequency through the placenta.

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El vólvulo de la vesícula biliar es una enfermedad preponderante en las personas ancianas y del sexo femenino. En niños es extremadamente raro. El rango de edad ocurre entre los 6 y 13 años, predomina en el sexo masculino, con una relación de 4:1; el paciente más joven reportado en la literatura es de dos años. Es una enfermedad rara en la que el órgano gira a lo largo de su eje comprometiendo su irrigación vascular. Esta enfermedad fue descrita por primera vez en 1898 por Wendel. El primer caso en niños se describió en 1925 por Daux. A la fecha, 14 casos han sido reportados en la literatura inglesa y 38 casos en la literatura japonesa. En México no encontramos registro de casos. Se reporta el primer caso mundial de vólvulo de vesícula en un recién nacido como causa inusual de abdomen agudo. Caso clínico: recién nacido masculino de 24 días de vida con vólvulo de la vesícula biliar que ameritó colecistectomía convencional.

Gallbladder volvulus is a disease most frequently seen in elderly people or women, but its presence in children is extremely rare. Its incidence occurs between 6 to 13 years, it is predominant in males, 4:1. The youngest case described in the literature was a two-year-old. It is considered a rare disease in which the organ rotates along its axis, compromising its vascular irrigation. It was first described in 1898 by Wendel; in children, it was first reported in 1925 by Daux. To date, only 14 cases have been documented in the English literature and 38 in the Japanese. In Mexico we did not find any case recorded. We report the first world-wide case of gallbladder volvulus in a newborn as unusual cause of acute abdomen. Case report: 24-day-old male newborn with acute abdomen due to a gallbladder volvulus that required conventional cholecystectomy.

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Small ruminant lentiviruses (SRLV) cause a multisystemic chronic disease affecting animal production and welfare. SRLV infections are spread across the world with the exception of Iceland. Success in controlling SRLV spread depends largely on the use of appropriate diagnostic tools, but the existence of a high genetic/antigenic variability among these viruses, the fluctuant levels of antibody against them and the low viral loads found in infected individuals hamper the diagnostic efficacy. SRLV have a marked in vivo tropism towards the monocyte/macrophage lineage and attempts have been made to identify the genome regions involved in tropism, with two main candidates, the LTR and env gene, since LTR contains primer binding sites for viral replication and the env-encoded protein (SU ENV), which mediates the binding of the virus to the host's cell and has hypervariable regions to escape the humoral immune response. Once inside the host cell, innate immunity may interfere with SRLV replication, but the virus develops counteraction mechanisms to escape, multiply and survive, creating a quasi-species and undergoing compartmentalization events. So far, the mechanisms of organ tropism involved in the development of different disease forms (neurological, arthritic, pulmonary and mammary) are unknown, but different alternatives are proposed. This is an overview of the current state of knowledge on SRLV genetic variability and its implications in tropism as well as in the development of alternative diagnostic assays.

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