Prognostic Factors of Survival in Patients With Gastric Cancer Under 45 Years Old Treated With Surgery in a Single Center in Mexico City.

Introduction Gastric cancer is a significant major global health concern, particularly prevalent in Asia. In recent years, a large number of new cases have been diagnosed worldwide, leading to a substantial number of deaths. The disease tends to present more aggressively in these cases, leading to debates about the prognosis and survival outcomes. Nonetheless, research has shown that survival rates improve significantly when the tumor is completely surgically resected. Materials and methods This retrospective study included patients between 16 and 45 years old, diagnosed with gastric cancer, with the support of the pathology department, who underwent surgery in the upper GI service, in the period from January 2006 to December 2012. Data collected encompassed variables such as gender, age, tumor size, type of surgery, overall survival, disease-free period, type and histological degree of the tumor, clinical stage of the cancer, and R0 resection (curative resection). All patients with a confirmed diagnosis of gastric cancer were included and treated with surgery and D1 limited dissection or extended D2 dissection. Patients who have received chemotherapy prior to surgical treatment and those who have been surgically treated outside the XXI Century National Medical Center were excluded. Results A total of 104 patients were included; the predominant histological type was diffuse adenocarcinoma accounting for 79.8% and 81.7% of the cases were histological grade 3. The most common clinical stage was IIIA in 41.3% of the cases. In 53.8% of the cases, we obtained an R0 resection. D2 lymphadenectomy was performed in 53.8% of the cases, with an overall survival rate of 82.69%. Significant prognostic factors for survival included T4 depth with an increase in risk for mortality (OR: 25.93; 95% CI: 6.41-53.54; p=0.001), lymph node status (OR: 14.76; 95% CI: 4.6-46.83; p<0.001), and size greater than 5 cm (OR: 1.8; 95% CI: 0.61-6.35; p<0.001). Conclusions Gastric cancer is more common in adults aged above 60 years old, but the incidence in young adults under 45 years old has been increasing. Although young gastric cancer patients present with more aggressive tumor behavior, these patients can have similar or even better overall survival compared to older patients, being 35% in some cases, especially in the resectable setting. Further research is still needed to fully characterize the unique biology and optimal management of gastric cancer in young adults.

Neoadjuvant Imatinib in Gastrointestinal Stromal Tumors (GIST): The First Analysis of a Mexican Population.

Introduction Gastrointestinal stromal tumors (GISTs) are neoplasms originating from the interstitial cells of Cajal, pacemaker cells responsible for intestinal motility. Patients with locally advanced GISTs and those with borderline resections due to the proximity of vital anatomical structures, which could result in unacceptable post-surgical morbidity, require special therapeutic consideration. Imatinib, a tyrosine kinase inhibitor, has demonstrated significant success in the non-surgical management of metastatic GIST, and its favorable impact on overall survival in the adjuvant setting makes it logical to speculate on the benefit it could provide as a neoadjuvant medication in patients with locally advanced disease. Methods Patients aged 18-90 years with a diagnosis of GIST confirmed by immunohistochemistry (CD117 positivity) who were treated at the Oncology Hospital of Centro Médico Nacional Siglo XXI in Mexico City from January 2012 to December 2016 were included in the study. It is a retrospective study with a duration of four years. Clinical data were collected from the medical records, which included sex, age, tumor location, initial resectability, reason for unresectability, initial tumor size, and mitotic rate. In the case of unresectable disease, patients who were evaluated by medical oncology and who had received treatment with 400 mg of imatinib daily were evaluated. Results A total of 312 patients diagnosed with GIST were analyzed. One hundred thirty-one were men (42%) with a mean age of 57 years, and 181 were women (58%) with a mean age of 59 years. The most frequent anatomical location was the stomach (n=185, 59.2%). At the time of diagnosis, 210 patients (67.3%) presented with resectable disease, while n=102 patients (32.7%) had unresectable disease. A total of 102 patients with unresectable disease received therapy with 400 mg of imatinib per day. Sixteen patients (15.7%) presented a reduction in tumor dimensions and underwent surgery. Conclusion The study highlights the importance of complete surgical resection and the potential benefit of neoadjuvant imatinib therapy in converting unresectable to resectable disease. The results suggest that imatinib can be effective in converting unresectable GISTs to resectable ones, allowing for a complete resection to be performed and obtaining an R0 resection in 93.7% of these cases.

Exploring the Photophysics and Photocatalytic Activity of Heteroleptic Rh(III) Transition-Metal Complexes Using High-Throughput Experimentation.

High-throughput synthesis and screening (HTSS) methods were used to investigate the photophysical properties of 576 heteroleptic Rh(III) transition-metal complexes through measurement of the UV-visible absorption spectra, deaerated excited-state lifetime, and phosphorescent emission spectra. While 4d transition-metal photophysics are often highly influenced by deleterious metal-centered deactivation channels, the HTSS of structurally diverse cyclometalating and ancillary ligands attached to the metal center facilitated the discovery of photoactive complexes exhibiting long-lived charge-transfer phosphorescence (0.15-0.95 µs) spanning a substantial portion of the visible region (546-620 nm) at room temperature. Further photophysical and electrochemical investigations were then carried out on select complexes with favorable photophysics to understand the underlying features controlling these superior properties. Heteroleptic Ir(III) complexes with identical ligand morphology were also synthesized to compare these features to this family of well understood chromophores. A number of these Rh(III) complexes contained the requisite properties for photocatalytic activity and were consequently tested as photocatalysts (PCs) in a water reduction system using a Pd water reduction cocatalyst. Under certain conditions, the activity of the Rh(III) PC actually surpassed that of the Ir(III) PC, uncovering the potential of this often-overlooked class of transition metals as both efficient photoactive chromophores and PCs.

Small Bowel Obstruction Secondary to Metastatic Urothelial Cell Carcinoma With Plasmacytoid Features: A Case Report.

Urothelial cell carcinoma (UCC) is a type of malignant cancer that affects thousands of people worldwide, especially those who smoke and have certain occupational exposures. Plasmacytoid urothelial carcinoma (PUC) is a rare histological variant of UCC that can present aggressively and insidiously. Small bowel obstruction secondary to malignancy is a rare presentation of UCC because the small bowel is a rare site of metastasis. We showcase a patient who presented with small bowel obstruction secondary to high-grade metastatic UCC with plasmacytoid features, exhibiting minimal urologic symptoms and no apparent risk factors. This case highlights the importance of high clinical suspicion for patients with possible malignancies that present with limited or unusual symptomatology and no risk factors. Further research into PUC to understand its symptoms and metastatic pattern is warranted to advance current early diagnostic criteria and further improve patient outcomes.

Clinicopathological Characteristics and the First Mutational Analysis of Gastrointestinal Stromal Tumors From Mexico: A Single Institution Experience.

Background Gastrointestinal stromal tumors (GISTs) arise from Cajal's interstitial cell precursors and display a variety of genetic mutations, primarily in the KIT and PDGFRA genes. These mutations are linked to tumor location, prognosis, and response to treatment. This study delves into the mutational patterns of GISTs in a Mexican population and their impact on overall survival (OS) and disease-free survival (DFS). Methodology This retrospective study examined 42 GIST cases diagnosed at the Oncology Hospital of the National Medical Center XXI Century between January 2018 and December 2020. Clinical, histological, and immunohistochemical data were gathered, and mutational analysis of KIT and PDGFRA genes was conducted using second-generation sequencing. Results The study group consisted of 52.4% females and 47.6% males, with an average age of 62.6 years. The most common tumor site was the stomach (59.5%), followed by the small intestine (26.2%). KIT mutations were detected in 71.4% of cases, predominantly involving exon 11. PDGFRA mutations were observed in 7.1% of cases. Recurrence was noted in 9.5% of patients, all with high-risk tumors. No significant link was identified between specific mutations and OS or DFS. Conclusions This investigation sheds light on the genetic landscape of GISTs in the Mexican population. While no significant association was established between particular mutations and survival outcomes, the study emphasizes the importance of molecular profiling in treatment decision-making. Further studies with larger sample sizes and longer follow-up periods are necessary to validate these results and explore their clinical relevance.

Combining multisensor images and social network data to assess the area flooded by a hurricane event.

In this study, multisensor remote sensing datasets were used to characterize the land use and land covers (LULC) flooded by Hurricane Willa which made landfall on October 24, 2018. The landscape characterization was done using an unsupervised K-means algorithm of a cloud-free Sentinel-2 MultiSpectral Instrument (MSI) image, acquired during the dry season before Hurricane Willa. A flood map was derived using the histogram thresholding technique over a Synthetic Aperture Radar (SAR) Sentinel-1 C-band and combined with a flood map derived from a Sentinel-2 MSI image. Both, the Sentinel-1 and Sentinel-2 images were obtained after Willa landfall. While the LULC map reached an accuracy of 92%, validated using data collected during field surveys, the flood map achieved 90% overall accuracy, validated using locations extracted from social network data, that were manually georeferenced. The agriculture class was the dominant land use (about 2,624 km2), followed by deciduous forest (1,591 km2) and sub-perennial forest (1,317 km2). About 1,608 km2 represents the permanent wetlands (mangrove, salt marsh, lagoon and estuaries, and littoral classes), but only 489 km2 of this area belongs to aquatic surfaces (lagoons and estuaries). The flooded area was 1,225 km2, with the agricultural class as the most impacted (735 km2). Our analysis detected the saltmarsh class occupied 541 km2in the LULC map, and around 328 km2 were flooded during Hurricane Willa. Since the water flow receded relatively quickly, obtaining representative imagery to assess the flood event was a challenge. Still, the high overall accuracies obtained in this study allow us to assume that the outputs are reliable and can be used in the implementation of effective strategies for the protection, restoration, and management of wetlands. In addition, they will improve the capacity of local governments and residents of Marismas Nacionales to make informed decisions for the protection of vulnerable areas to the different threats derived from climate change.

Focal-to-bilateral tonic-clonic seizures and High-grade CMV-infection are poor survival predictors in Tumor-related Epilepsy Adult-type diffuse gliomas-A single-center study and literature review.

Introduction: Previous studies have reported a correlation between a high-grade CMV-infection and an unfavorable prognosis in glioblastoma (GB). Coversely, epilepsy has been associated with a more favorable outcome in GB patients. Despites epilepsy and CMV share similar molecular mechanisms in GB tumoral microenvironment, the correlation between Tumor-Related-Epilepsy (TRE) and CMVinfection remains unexplored. The aim of our study is to examine the correlation between the dregree of CMV infection and seizure types on the survival of TRE Adult-type-diffuse-glioma. To achieve this objective, we conducted a comprehensive literature review to assess our results regarding previous publications. Methods: We conducted a retrospective-observational study on TRE Adult-type-diffuse-gliomas treated at a single center in Mexico from 2010 to 2018. Tumor tissue and cDNA were analyzed by immunochemistry (IHC) for CMV (IE and LA antigens) at the Karolinska Institute in Sweden, and RT-PCR for CMV-gB in Torreon Mexico, respectively. Bivariate analysis (X2-test) was performed to evaluate the association between subtypes of Adult-type-diffuse-glioma (IDH-mut grade 4 astrocytoma vs. IDH-wt glioblastoma) and the following variables: type of hemispheric involvement (mesial vs. neocortical involvement), degree of CMV infection (<25%vs. >25% infected-tumoral cells) and seizure types [Focal awareness, focal impaired awareness, and FBTCS]. Kaplan Meier and Cox analyses were performed to determine the risk, p < 0.05 was considered statistically significant. Results: Sixty patients with TRE Adult type diffuse gliomas were included (80% IDH-wt glioblastoma and 20% IDH-mut grade 4astrocytomas). The mean age was 61.5 SD ± 18.4, and 57% were male. Fifty percent of the patients presented with mesial involvement of the hemysphere. Seizure types included focal awareness (15%), focal impaired awareness (43.3%), and FBTCS (41.7%). Ninety percent of cases were treated with Levetiracetam and 33.3% presented Engel-IA postoperative seizure control. More than 90% of samples were positive for CMV-immunohistochemistry (IHC). However, all cDNA analyzed by RT-PCR return negative results. The median of overall survival (OS) was 15 months. High-grade CMV-IE infection (14 vs. 25 months, p<0.001), mesial involvement (12 vs. 18 months, p<0.001), and FBTCS were associated with worse OS (9 vs.18 months for non-FBTCS). Multivariate analysis demonstrated that high-grade CMV infection (HR = 3.689, p=0.002) and FBTCS (HR=7.007, p<0.001) were independent unfavorable survival factors. Conclusions: CMV induces a proinflammatory tumoral microenvironment that contributes to the developmet of epilepsy. Tumor progression could be associated not only with a higher degree of CMV infection but also to epileptogenesis, resulting in a seizure phenotype chracterized by FBTCS and poor survival outcomes. This study represents the first survival analysis in Latin America to include a representative sample of TRE Adult-type diffuse gliomas considering CMV-infection-degree and distinguishing features (such as FBTCS) that might have potential clinical relevance in this group of patients. Further prospective studies are required to validate these results.

Protein Quality Control Systems and ER Stress as Key Players in SARS-CoV-2-Induced Neurodegeneration.

The COVID-19 pandemic has brought to the forefront the intricate relationship between SARS-CoV-2 and its impact on neurological complications, including potential links to neurodegenerative processes, characterized by a dysfunction of the protein quality control systems and ER stress. This review article explores the role of protein quality control systems, such as the Unfolded Protein Response (UPR), the Endoplasmic Reticulum-Associated Degradation (ERAD), the Ubiquitin-Proteasome System (UPS), autophagy and the molecular chaperones, in SARS-CoV-2 infection. Our hypothesis suggests that SARS-CoV-2 produces ER stress and exploits the protein quality control systems, leading to a disruption in proteostasis that cannot be solved by the host cell. This disruption culminates in cell death and may represent a link between SARS-CoV-2 and neurodegeneration.

Pathogenic bacteria prevalence in cultured Nile tilapia in Southwest Mexico: A real-time PCR analysis.

The present study investigates molecular-based PCR techniques to estimate the prevalence of fish pathogens in southwest Mexico where recurrent mortality in the tilapia cultures has been observed. Sample of internal organs and lesions of Nile tilapia were taken and analysed in 2018, 2019, 2020 and 2022 to detect bacterial pathogens using PCR. No samples were taken in 2021 due to the COVID-19 pandemic. The real-time PCR conditions were optimized to allow a qualitative reliable detection of the bacteria from fixed fish tissue. A total of 599 pond- and cage-cultured tilapia from the southwestern Mexican Pacific (Guerrero, Oaxaca and Chiapas states) were analysed. In this tropical region, during 2018 and 2019 water temperatures of the tilapia cultures were generally with the optimal range to grow Nile tilapia, although extreme values were recorded on some farms. Most of the tilapia sampled were apparently healthy. No Francisella sp. was detected in any sample, and Staphylococcus sp. was the most prevalent (from 0% to 64%) bacteria from the three states over time. Low prevalence of Aeromonas sp. was found, from 0% to 4.3%, although the fish pathogen Aeromonas dhakensis was not detected. Sterptococcus iniae was only detected in Chiapas in 2019 at a low prevalence (1.4%), while the major tilapia pathogen S. agalactiae was detected at a high prevalence (from 0% to 59%) in the three Mexican states. This is the first detection of these pathogenic bacteria in rural farms using real-time PCR and constitutes a great risk for tilapia aquaculture in Mexico, as well as a potential dispersion of these pathogens to other aquaculture areas.

[Extremity soft tissue sarcoma: does surgical margin impact survival?] / Sarcomas de tejidos blandos en las extremidades: ¿el margen quirúrgico impacta la sobrevida?

Objective: To define the impact of surgical margins on local recurrence (LR), distant recurrence (DR) and overall survival (OS) in patients with soft tissue sarcomas of the extremities (eSTS). Method: Patients treated for a primary eSTS from 2006 to 2010 were analyzed. Rates of local recurrence, distant recurrence, and overall survival were estimated using the Kaplan-Meier method. The association of possible prognostic factors such as local recurrence, metastasis, and survival was performed using the Cox proportional hazards model. Results: 128 patients were analyzed. The surgical margins were positive (R1 resection) in 22.7% and negative in 77.3%. The LR was 27%, the DR was 13% (70% of the population was free of disease at 5 years) and OS at 5 years was 84%. The prognostic factors for OS at 5 years were clinical stage, type and histological grade. The surgical margin had no impact on OS. Conclusions: Although an adequate oncological resection cannot be underestimated, this should be considered in the decision of the optimal treatment of eSTS when amputation or significant functional impairment of the limb is required to obtain negative surgical margins.

Objetivo: Definir el impacto de los márgenes quirúrgicos sobre la recurrencia local (RL), la recurrencia a distancia (RD) y la supervivencia global (SG) en pacientes con sarcomas de tejidos blandos de las extremidades (STBe). Método: Se analizaron pacientes tratados por un STBe primario desde 2006 hasta 2010. Las tasas de recurrencia local, recurrencia a distancia y sobrevida global se estimaron mediante el método de Kaplan-Meier. La asociación de posibles factores pronósticos como recidiva local, metástasis y supervivencia se realizó mediante el modelo de riesgos proporcionales de Cox. Resultados: Se analizaron 128 pacientes. Los márgenes quirúrgicos fueron positivos (resección R1) en el 22.7% y negativos en el 77.3%. La RL fue del 27% y la RD fue del 13% (el 70% de la población está libre de enfermedad a 5 años) y la SG a 5 años fue del 84%. Los factores pronósticos para la SG a 5 años fueron el estadio clínico, el tipo y el grado histológico. El margen quirúrgico no tuvo impacto en la SG. Conclusiones: Aunque no se puede subestimar una resección oncológica adecuada, esto se debe considerar en la decisión del tratamiento óptimo de los STBe cuando se requiere una amputación o un deterioro funcional significativo de la extremidad para obtener márgenes quirúrgicos negativos.

High expression of both desmoplastic stroma and epithelial to mesenchymal transition markers associate with shorter survival in pancreatic ductal adenocarcinoma.

Desmoplastic stroma (DS) and the epithelial-to-mesenchymal transition (EMT) play a key role in pancreatic ductal adenocarcinoma (PDAC) progression. To date, however, the combined expression of DS and EMT markers, and their association with variations in survival within each clinical stage and degree of tumor differentiation is unknown. The purpose of this study was to investigate the association between expression of DS and EMT markers and survival variability in patients diagnosed with PDAC. We examined the expression levels of DS markers alpha smooth muscle actin (α-SMA), fibronectin, and vimentin, and the EMT markers epithelial cell adhesion molecule (EPCAM), pan-cytokeratin, and vimentin, by immunohistochemistry using a tissue microarray of a retrospective cohort of 25 patients with PDAC. The results were examined for association with survival by clinical stage and by degree of tumor differentiation. High DS markers expression -α-SMA, fibronectin, and vimentin- was associated with decreased survival at intermediate and advanced clinical stages (p=0.006-0.03), as well as with both poorly and moderately differentiated tumor grades (p=0.01-0.02). Interestingly, the same pattern was observed for EMT markers, i.e., EPCAM, pan-cytokeratin, and vimentin (p=0.00008-0.03). High expression of DS and EMT markers within each clinical stage and degree of tumor differentiation was associated with lower PDAC survival. Evaluation of these markers may have a prognostic impact on survival time variation in patients with PDAC.

Giant liver teratoma with gliosis peritonei treated by right extended hepatectomy: Overview and case report.

Germ cell tumors (GCTs) are considered as extragonadal if there is no evidence of a primary tumor in the testes or ovaries. GCTs can be classified as seminomas, non-seminomatous, mature teratomas, and immature teratomas based upon histology. Mature teratomas are generally found in prepuberal children. Less than 1% of them have been reported in the gastrointestinal tract and liver. Liver teratomas are extremely rare. There are only 11 cases reported in adults up to 2018. Isolated liver metastasis of ovarian teratoma is also very rare. We present a case of a late metachronous recurrence of liver cystic teratoma with gliosis peritonei in a female adult treated by a right extended hepatectomy along with a literature review.

Association of MGAT4C with major neurocognitive disorder in the Mexican population.

BACKGROUND: Neurocognitive disorders (NCDs) are characterized by cognitive decline. Most genetic studies of NCDs have been focused on single-nucleotide polymorphism; other genetic variations, such as copy number variants (CNV), have been less explored. The aim of the present study was to explore CNVs associated with NCDs in a small sample of Mexican individuals and search for the frequency in a larger replication sample of individuals at high-risk for or diagnosed with NCDs. METHOD: The exploratory analysis analyzed whole-genome CNVs associated with NCDs in 1335 individuals, of whom 35 were diagnosed with NCDs and 1300 were population-based controls. Whole-genome CNVs were derived from PsychArray and the PennCNV algorithm. The frequency of associated CNVs in a sample of 277 individuals diagnosed with NCDs and 70 high-risk individuals was then determined using RT-PCR. RESULTS: The exploratory analysis identified one deletion associated with NCDs (p = 0.007) affecting the gene MGAT4C (Mannosyl (Alpha-1,3-)-Glycoprotein Beta-1,4-N-Acetylglucosaminyltransferase, Isozyme C). In the replication sample, a frequency of 3.97% was found in individuals diagnosed with NCDs and 1.43% in high-risk individuals. CONCLUSIONS: An association between a rare CNV on MGAT4C and cognitive impairment was found in this sample of the Mexican population. Nevertheless, studies with larger sample sizes are needed in order to further explore the association.

Cell Death Related Proteins Beyond Apoptosis in the CNS.

Cell death related (CDR) proteins are a diverse group of proteins whose original function was ascribed to apoptotic cell death signaling. Recently, descriptions of non-apoptotic functions for CDR proteins have increased. In this minireview, we comment on recent studies of CDR proteins outside the field of apoptosis in the CNS, encompassing areas such as the inflammasome and non-apoptotic cell death, cytoskeleton reorganization, synaptic plasticity, mitophagy, neurodegeneration and calcium signaling among others. Furthermore, we discuss the evolution of proteomic techniques used to predict caspase substrates that could potentially explain their non-apoptotic roles. Finally, we address new concepts in the field of non-apoptotic functions of CDR proteins that require further research such the effect of sexual dimorphism on non-apoptotic CDR protein function and the emergence of zymogen-specific caspase functions.

[Morbimortalidad de la pancreatoduodenectomía en pacientes con cáncer de páncreas y tumores periampulares en el Hospital de Oncología del Centro Médico Nacional Siglo XXI de 2008 a 2013]. / Morbimortality of pancreatoduenectomy in patients with cancer of pancreas and periampular tumors in the Oncology Hospital of Centro Médico Nacional Siglo XXI from 2008 to 2013.

INTRODUCTION: Pancreatic tumors and periampullary tumors have a similar clinical presentation; pancreatoduodenectomy represents the only possibility of cure or of increasing survival; with an average mortality of 5-10% and a morbidity of 20-40%. OBJECTIVE: To determine the morbidity and mortality secondary to the pancreatoduodenectomy intervention in patients with pancreatic cancer or periampullary tumors in the Oncology Hospital of Centro Médico Nacional Siglo XXI (Mexico City) from 2008 to 2013. METHOD: Historical, observational and descriptive cohort carried out in the department of sarcomas and tumors of the upper digestive tube of the Oncology Hospital of Centro Médico Nacional Siglo XXI, postoperative pancreatoduodenectomy from 2008 to 2013. RESULTS: We included 71 patients who underwent pancreatoduodenectomy, 47 (66.2%) were female and 24 (33.8%) were male. The average age was 60.3 years. The most common histology was cancer of the Vater's ampulla (66.2%). The resections were R0 in 95.8% of the cases. Mortality was 4.22% and morbidity was 69%. The most frequent complication was pancreatic fistula (23.9%). In the statistical analysis, perioperative transfusion was associated with surgical complications (p < 0.007). CONCLUSIONS: The morbidity of pancreatoduodenectomy is greater than that reported in the literature, however, it does not influence mortality that is similar to that reported in other centers. The number of lymph nodes resected; as well as the percentage of negative margins are those accepted worldwide; It is concluded that this is derived from the experience of the center where these procedures are performed. No factor with statistical significance was found, only the transfusion that increased the complications.

INTRODUCCIÓN: Los tumores de páncreas y los tumores periampulares tienen una presentación clínica similar. La pancreatoduodenectomía representa la única posibilidad de curación o de aumentar la sobrevida, con una mortalidad promedio del 5-10% y una morbilidad del 20-40%. OBJETIVO: Determinar la morbilidad y la mortalidad secundarias a la intervención de pancreatoduodenectomía en pacientes con cáncer de páncreas o tumores periampulares en el Hospital de Oncología del Centro Médico Nacional SXXI de 2008 a 2013. MÉTODO: Cohorte histórica, observacional y descriptiva, realizada en el departamento de sarcomas y tumores de tubo digestivo alto del Hospital de Oncología del Centro Médico Nacional Siglo XXI, operados de pancreatoduodenectomía entre 2008 y 2013. RESULTADOS: Se incluyeron 71 pacientes que se sometieron a pancreatoduodenectomía; 47 (66.2%) eran de sexo femenino y 24 (33.8%) de sexo masculino. La edad promedio fue de 60.3 años. La histología más común fue cáncer de ámpula de Vater (66.2%). Las resecciones fueron R0 en el 95.8% de los casos. La mortalidad fue del 4.22% y la morbilidad fue del 69%. La complicación más frecuente fue la fístula pancreática (23.9%). En el análisis estadístico, la transfusión perioperatoria se asoció a complicaciones quirúrgicas (p < 0.007). CONCLUSIONES: La morbilidad de la pancreatoduodenectomía es mayor que lo reportado en la literatura; sin embargo, no influye en la mortalidad, que es similar a lo reportado en otros centros. El número de ganglios resecados, así como el porcentaje de márgenes negativos, son los aceptados internacionalmente. Se concluye que esto se deriva de la experiencia del centro donde se realizan estos procedimientos. No se encontró ningún factor con relevancia estadística, excepto la transfusión, que incrementaba las complicaciones.

The Diagnostic Usefullness of the Salivary Pepsin Test in Symptomatic Laryngopharyngeal Reflux.

OBJECTIVE: Laryngopharyngeal Reflux (LPR) is a disease characterized by the presence of symptoms, signs and tissue alterations in the aero-digestive upper tract as a consequence of the gastric contents retrograde movement. In most cases diagnosis is clinical and it is established by the presence of symptoms and endoscopic laryngeal signs. The aim of the study was to determine the sensitivity, specificity, positive and negative Likelihood Ratio (LR) of the salivary pepsin assay (PEP-test, RD Biomed, Hull, UK) as diagnostic tool of LPR. STUDY DESIGN: Diagnostic Accuracy Study. METHOD: 221 subjects aged between 26 and 68 years were recruited. All subjects completed the Reflux Symptom Index scale. PEP-test was carried out on fasting subjects, and a second test was performed one hour after the main meal, only on those subjects with a fasting negative result. RESULTS: Fasting PEP-test showed a 98% specificity, 40% sensitivity, positive LR of 16.4 and negative LR of 0.61. The use of both PEP-test showed a 95% specificity, 48% sensitivity, positive LR of 9.61 and negative LR of 0.55. CONCLUSIONS: The PEP-test is a simple, inexpensive, non-invasive and easily reproducible test that should be considered as an alternative diagnosis tool for LPR diagnosis. When there is a clinical suspicion of LPR disease, a positive result on the test could be considered diagnostic, but on subjects with negative results it should be complemented with more complex tests such as the 24-hour dual-channel pH-metry.

[Programa de detección del alelo APOE-E4 en adultos mayores mexicanos con deterioro cognitivo].

INTRODUCTION: In Mexico, the prevalence of neurocognitive disorders (NCDs) has increased in parallel with the increase in life expectancy. The E4 allele of the gene that encodes apolipoprotein E (APOE) is the main genetic risk factor for cognitive impairment. OBJECTIVE: To replicate the association of APOE-E4 allele with neurocognitive impairment in a Mexican population, as well as to implement a genetic risk-detection program with the APOE-E4 allele. METHOD: A program was structured for the detection of APOE-E4 allele risk in different recruiting centers from the central zone of the Mexican Republic, with three stages: recruitment and selection of candidates for the detection of the risk-allele, genetic risk analysis and delivery of results. RESULTS: In the genetic-association study to replicate the association with neurocognitive disorders by means of multivariate logistic models, the APOE-E4 allele increased the risk for cognitive impairment in the Mexican populations by approximately 6 % (OR: 5.83, p = 0.0025). In addition, 367 genetic risk results were delivered. CONCLUSIONS: The present program is the first one to be implemented in Mexico with the purpose to inform on a genetic risk factor for neurocognitive disorders in several centers of the country.

INTRODUCCIÓN: En México, la prevalencia de los trastornos neurocognitivos (TNC) han aumentado a la par del incremento en la esperanza de vida. El alelo E4 del gen que codifica la apolipoproteína E (APOE) es el principal factor de riesgo genético para deterioro neurocognitivo. OBJETIVO: Reproducir la asociación en población mexicana entre APOE-E4 y el deterioro neurocognitivo, así como implementar un programa de detección de riesgo genético con el alelo APOE-E4. MÉTODO: Se estructuró un programa de detección de riesgo basado en APO-EA en diferentes centros de reclutamiento en la zona centro de la República Mexicana, con tres etapas: reclutamiento y selección de los candidatos para la detección del alelo de riesgo, análisis del riesgo genético y entrega del resultado. RESULTADOS: El análisis de asociación genética para replicar la asociación con trastornos neurocognitivos mediante modelos logísticos multivariados mostró que el alelo E4 de APOE incrementó aproximadamente 6 % el riesgo en población mexicana (RM = 5.83, p = 0.0025). Se entregaron 367 resultados de riesgo genético. CONCLUSIONES: El presente programa es el primero en México implementado para dar a conocer un factor de riesgo genético para trastornos neurocognitivos en varios centros del país.

Retrospective cohort of pancreatic and Vater ampullary adenocarcinoma from a reference center in Mexico.

INTRODUCTION: Pancreatic ductal adenocarcinoma (PDAC) and ampulla of Vater adenocarcinomas (AVAC) are periampullary tumors. These tumors have overlapping symptoms and a common treatment, but present differences in their survival and biology. No recent studies in Mexico have been published that describe the clinicopathological characteristics of these tumors. Therefore, the aim of this study was to describe the clinicopathological characteristics of PDAC and AVAC in patients at a reference center in Mexico. METHODS: A retrospective cohort of patients with PDAC or AVAC was analyzed at our institution (July 2007 to June 2016). Inferential analysis of the clinical data was performed with Student's t-test or a χ2 test with odds ratios (OR) and confidence intervals (CI), depending on the variables. Overall survival was compared using Kaplan-Meier curves with log-rank p values. RESULTS: Forty patients with PDAC and 76 with AVAC were analyzed, including 77 females and 39 males with a mean age of 60.6 years and a mean evolution time of 5.7 months. PDAC patients had more abdominal pain, a larger tumor size and more advanced stages than AVAC patients. In contrast, AVAC patients had more jaundice, a higher percentage of complete resections and higher overall survival. Up to 70% of patients were overweight. PDAC cohort included a higher proportion of smokers. CONCLUSIONS: Our cohort was slightly younger, had a larger percentage of females, and a greater percentage of obese patients than those in many international reports. A high proportion of PDAC patients are diagnosed in advanced stages and have a low likelihood of resectability.

CapsidMesh: Atomic-detail structured mesh representation of icosahedral viral capsids and the study of their mechanical properties.

Viruses are the most abundant pathogens affecting all forms of life. A major component of a virus is a protein shell, known as the viral capsid, that encapsulates the genomic material. The fundamental functions of the capsid are to protect and transport the viral genome and recognize the host cell. Descriptions of this macromolecular complex have been proposed at different scales of approximation. Here, we introduce a methodology to generate a structured volumetric mesh of icosahedral viral capsids (CapsidMesh) based on the atomic positions of their constituents. Material properties of the capsid proteins can be set on every mesh element individually. Hence, we have control over all levels of protein structure (atoms, amino acids, subunits, oligomers, and capsid). The CapsidMesh models are suitable for numerical simulations and analysis of a physical process using a third-party package. In particular, we used our methodology to generate a CapsidMesh of several capsids previously characterized by atomic force microscopy experiments and then simulated the mechanical nanoindentation through the finite element method. By fitting to the experimental linear elastic response, we estimated the elastic modulus and mechanical stresses produced on the capsids. Our results show that the atomic detail of the CapsidMesh is sufficient to reproduce anisotropic properties of the particle.

Role of oceanography in shaping the genetic structure in the North Pacific hake Merluccius productus.

Determining the relative influence of biotic and abiotic factors on genetic connectivity among populations remains a major challenge in evolutionary biology and in the management and conservation of species. North Pacific hake (Merluccius productus) inhabits upwelling regions in the California Current ecosystem from the Gulf of California to the Gulf of Alaska. In this study, we examined mitochondrial DNA (mtDNA) and microsatellite variation to estimate levels of genetic differentiation of M. productus in relation to the role of oceanographic features as potential barriers to gene flow. Samples were obtained from nine sites spanning a large part of the geographic range of the species, from Puget Sound, Washington to Costa Rica. The microsatellite results revealed three genetically discrete populations: one spanning the eastern Pacific coast, and two apparently resident populations circumscribed to the Puget Sound and the northern Gulf of California (FST = 0.032, p = 0.036). Cytochrome b sequence data indicated that isolation between the Puget Sound and northern Gulf of California populations from the coastal Pacific were recent phenomena (18.5 kyr for Puget Sound and 40 kyr for the northern Gulf of California). Oceanographic data obtained from the Gulf of California support the hypothesis that permanent fronts within the region, and strong gradients at the entrance to the Gulf of California act as barriers to gene flow. A seascape genetics approach found significant genetic-environment associations, where the daytime sea surface temperature and chlorophyll concentrations were the best predictive variables for the observed genetic differentiation. Considering the potential causes of genetic isolation among the three populations, e.g. spawning areas in different latitudes associated with upwelling processes, oceanographic barriers, asymmetric migration and specialized diet, oceanographic barriers appear to be a likely mechanism restricting gene flow.