Diversidad genética de polimorfismos autosómicos en poblaciones africanas

El continente africano es la fuente de todos los seres humanos anatómicamente modernos, que más tarde se dispersaron por todo el planeta. África posee el mayor nivel de variación genética, por lo que es una región de interés a estudiar. En este trabajo se ha analizado como se distribuye la variabilidad genética en África con cada uno de los polimorfismos estudiados, polimorfismos de nucleótido simple (SNP), grupos sanguíneos y microsatélites (STR) y se ha comparado la información que ofrece cada tipo de marcador. Se observa una diferenciación sobre todo de las familias Khoi-San y afroasiáticos pero con diferencias según que tipo de polimorfismo que se ha estudiado. En general la selección natural parece haber afectado de forma similar a SNPs de genes codificantes y a grupos sanguíneos

Development, Optimisation and Validation of a Novel Multiplex Real-Time PCR Method for the Simultaneous Detection of Cryptosporidium spp., Giardia duodenalis and Dientamoeba fragilis

The enteric protozoan parasites Cryptosporidium spp., Giardia duodenalis and Dientamoeba fragilis are—to various extents—contributors to the burden of gastrointestinal illness in high-income countries. Detection of these pathogens by microscopy examination is challenging because of the limited sensitivity and need for specific staining procedures. We developed and optimised a new multiplex real-time PCR assay for the simultaneous detection of Cryptosporidium spp., G. duodenalis and D. fragilis in clinical (stool) samples. The diagnostic performance of the assay was evaluated against a large panel of well-characterised DNA samples positive for Cryptosporidium spp. (n = 126), G. duodenalis (n = 132) and D. fragilis (n = 49). The specificity of the test was assessed against a DNA panel from other intestinal or phylogenetically related parasites (n = 105) and faecal DNA from individuals without clinical manifestations (n = 12). The assay exhibited a diagnostic sensitivity of 0.90–0.97 and a diagnostic specificity of 1. The limit of detection was estimated for Cryptosporidium (1 oocyst) and G. duodenalis (5 × 10−4 cysts). The method allowed the detection of four Cryptosporidium species (C. hominis, C. parvum, C. meleagridis and C. cuniculus) and five G. duodenalis assemblages (A–E) without cross-reacting with other parasites belonging to the phyla Amoebozoa, Apicomplexa, Euglenozoa, Microsporidia, Nematoda and Platyhelminthes. This newly developed multiplex real-time PCR assay represents a novel alternative for the rapid and accurate detection of Cryptosporidium, G. duodenalis and D. fragilis in clinical settings

“Long-term oncologic outcomes and risk factors for distant recurrence after pathologic complete response following neoadjuvant treatment for locally advanced rectal cancer. A nationwide, multicentre study”

Background: Pathologic complete response (pCR) after multimodal treatment for locally advanced rectal cancer (LARC) is used as surrogate marker of success as it is assumed to correlate with improved oncologic outcome. However, long-term oncologic data are scarce.Methods: This retrospective, multicentre study updated the oncologic follow-up of prospectively collected data from the Spanish Rectal Cancer Project database. pCR was described as no evidence of tumour cells in the specimen. Endpoints were distant metastases-free survival (DMFS) and overall survival (OS). Multivariate regression analyses were run to identify factors associated with survival.Results: Overall, 32 different hospitals were involved, providing data on 815 patients with pCR. At a median follow-up of 73.4 (IQR 57.7-99.5) months, distant metastases occurred in 6.4% of patients. Abdominoperineal excision (APE) (HR 2.2, 95%CI 1.2-4.1, p = 0.008) and elevated CEA levels (HR = 1.9, 95% CI 1.0-3.7, p = 0.049) were independent risk factors for distant recurrence. Age (years) (HR 1.1; 95% CI 1.05-41.09; p < 0.001) and ASA III-IV (HR = 2.0; 95%-CI 1.4-2.9; p < 0.001), were the only factors associated with OS. The estimated 12, 36 and 60-months DMFS rates were 96.9%, 91.3%, and 86.8%. The estimated 12, 36 and 60-months OS rates were 99.1%, 94.9% and 89.3%.Conclusions: The incidence of metachronous distant metastases is low after pCR, with high rates of both DMFS and OS. The oncologic prognosis in LARC patients that achieve pCR after neoadjuvant chemoradiotherapy is excellent in the long term. (c) 2023 Elsevier Ltd, BASO similar to The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved