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2.
Neurol Sci ; 45(7): 3325-3332, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38353847

RESUMEN

BACKGROUND: Antiplatelet agents have been shown to worsen outcomes following traumatic injury. Research on desmopressin (DDAVP) and platelet transfusion for antiplatelet reversal is limited. We aimed to evaluate the effect of these agents on patients taking pre-injury antiplatelet medications who experienced traumatic brain injury (TBI) after blunt trauma. METHODS: This is a retrospective cohort study of adult trauma patients from 2014 to 2021 on aspirin and/or a P2Y12 inhibitor. Patients were stratified into groups based on if they received DDAVP, platelets, both agents, or neither. RESULTS: Of 5525 included patients, 4696 (85.4%) were not reversed, 461 (8.4%) received platelets, 173 (3.1%) received DDAVP, and 172 (3.1%) received both reversals. There was no statistically significant difference in length of stay between, but patients who received platelets or both reversals were more likely to have hospital complications (p < 0.05), longer hospital length of stay (p < 0.001), and longer ICU length of stay (p < 0.001) compared to those who did not receive reversal. A subgroup analysis of patients with a head AIS of 4 or 5 confirmed these findings. CONCLUSIONS: Patients who received platelets or both reversals had a longer length of hospital stay and length of ICU stay. It is difficult to recommend one treatment over another based on our results alone. Further studies are needed to help clarify the risks and benefits of reversal agents in this patient population.


Asunto(s)
Lesiones Traumáticas del Encéfalo , Desamino Arginina Vasopresina , Inhibidores de Agregación Plaquetaria , Transfusión de Plaquetas , Humanos , Lesiones Traumáticas del Encéfalo/terapia , Lesiones Traumáticas del Encéfalo/tratamiento farmacológico , Masculino , Femenino , Inhibidores de Agregación Plaquetaria/uso terapéutico , Persona de Mediana Edad , Estudios Retrospectivos , Adulto , Desamino Arginina Vasopresina/uso terapéutico , Anciano , Tiempo de Internación/estadística & datos numéricos , Aspirina/uso terapéutico , Hemostáticos/uso terapéutico , Antagonistas del Receptor Purinérgico P2Y/uso terapéutico , Estudios de Cohortes
3.
Dis Colon Rectum ; 67(2): 313-321, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-37703205

RESUMEN

BACKGROUND: Ileostomies constitute 15% to 43% of readmissions after colorectal surgery, often due to dehydration and acute kidney injury. Prior institutional interventions decreased readmissions but not among patients who underwent new ileostomies. OBJECTIVE: To evaluate readmissions among patients who underwent new ileostomies after postoperative oral rehydration solution and standardized clinic visits. DESIGN: Retrospective analysis of prospective database. SETTINGS: Enhanced recovery colorectal surgery service. PATIENTS: Patients who underwent new ileostomy before and after intervention. INTERVENTIONS: Postoperative oral rehydration solution and postdischarge clinic visits with review of inputs/outputs, antimotility and appliance needs, and trained nurse reeducation 4 to 7 days after discharge, 30 days postoperatively, and every 1 to 2 weeks thereafter as needed. MAIN OUTCOME MEASURES: Readmission rate due to dehydration/acute kidney injury (primary), emergency department visits, and readmission rates overall and for specific diagnoses. Analysis used univariate and weighted techniques. RESULTS: A total of 312 patients (199 preintervention; 113 postintervention) were included, with a mean age of 59.0 years. Patients were predominantly White (94.9%) and evenly split between men and women. The most common diagnosis was diverticulitis (43.3%). The most common procedure was high anterior resection (38.8%), followed by low anterior resection (16.35%). Patient and procedure characteristics were well matched between groups. Multivariate analysis demonstrated that readmission rate due to dehydration/acute kidney injury significantly decreased between pre- and postintervention study groups (45.7% vs 16.5%, p = 0.039). Emergency department visits due to dehydration/acute kidney injury (12.0% vs 1.7%, p < 0.001) and readmissions from all causes (24.33% vs 10.6%, p = 0.005) also significantly decreased. Other complications were not significantly different between groups. Average stoma output 24 hours before (776 vs 625 mL, p = 0.005) and after (993 vs 890 mL, p = 0.025) discharge was significantly decreased in the postintervention group. LIMITATIONS: Retrospective single-center study. CONCLUSIONS: An oral rehydration solution and frequent standardized postdischarge visits led by trained nursing staff decreased readmissions and emergency department visits among patients who underwent new ileostomies after colorectal surgery. See Video Abstract . LA REHIDRATACIN ORAL POSOPERATORIA Y EL SEGUIMIENTO REGLAMENTADO REDUCEN LOS REINGRESOS EN PACIENTES DE CIRUGA COLORRECTAL CON ILEOSTOMAS: ANTECEDENTES:Las ileostomías constituyen del 15 al 43% de los reingresos después de la cirugía colorrectal, a menudo debido a la deshidratación y la lesión renal aguda. Las intervenciones institucionales previas redujeron los reingresos, pero no entre los pacientes con nuevas ileostomías.OBJETIVO:Evaluar los reingresos entre pacientes con nuevas ileostomías después del uso de solución de rehidratación oral postoperatoria y visitas clínicas estandarizadas.DISEÑO:Análisis retrospectivo de base de datos prospectiva.AJUSTES:Servicio de cirugía colorrectal de recuperación mejorada.PACIENTES:Pacientes con ileostomía nueva antes y después de la intervención.INTERVENCIÓN(ES):Solución de rehidratación oral posoperatoria y visitas clínicas posteriores al alta con revisión de entradas/salidas, antimotilidad y necesidades de aparatos, y reeducación de enfermeras capacitadas 4-7 días después del alta, 30 días después de la operación y cada 1-2 semanas después, según sea necesario.PRINCIPALES MEDIDAS DE RESULTADO:Tasa de readmisión debido a deshidratación/lesión renal aguda (primaria), tasa de urgencias y de readmisión en general y para diagnósticos específicos. El análisis utilizó técnicas univariadas y ponderadas.RESULTADOS:Se incluyeron un total de 312 pacientes (199 preintervención; 113 postintervención), con una edad media de 59,0 años. Los pacientes eran predominantemente blancos (94,9%) y se dividieron equitativamente entre hombres y mujeres. El diagnóstico más frecuente fue diverticulitis (43,3%). El procedimiento más común fue la resección anterior alta (38,8 %) seguida de la resección anterior baja (16,35 %). Las características del paciente y del procedimiento coincidieron bien entre los grupos. El análisis multivariante demostró que la tasa de reingreso debido a deshidratación/lesión renal aguda disminuyó significativamente entre los grupos de estudio antes y después de la intervención (45,7 % frente a 16,5 %, p = 0,039). Las visitas a urgencias por deshidratación/insuficiencia renal aguda (12,0 % frente a 1,7 %, p < 0,001) y los reingresos por todas las causas (24,33 % frente a 10,6 %, p = 0,005) también disminuyeron significativamente. Otras complicaciones no fueron significativamente diferentes entre los grupos. El gasto medio del estoma 24 horas antes (776 ml frente a 625 ml, p = 0,005) y después (993 ml frente a 890 ml, p = 0,025) del alta disminuyó significativamente en el grupo posterior a la intervención.LIMITACIONES:Estudio retrospectivo de centro único.CONCLUSIONES:Una solución de rehidratación oral y frecuentes visitas estandarizadas posteriores al alta dirigidas por personal de enfermería capacitado redujeron los reingresos y las visitas al servicio de urgencias entre los pacientes con nuevas ileostomías después de la cirugía colorrectal. ( Traducción-Dr. Yolanda Colorado ).


Asunto(s)
Lesión Renal Aguda , Cirugía Colorrectal , Diverticulitis , Masculino , Humanos , Femenino , Persona de Mediana Edad , Estudios Retrospectivos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/terapia , Complicaciones Posoperatorias/diagnóstico , Ileostomía/métodos , Deshidratación/etiología , Deshidratación/terapia , Deshidratación/diagnóstico , Readmisión del Paciente , Soluciones para Rehidratación , Estudios de Seguimiento , Cuidados Posteriores , Alta del Paciente , Fluidoterapia/efectos adversos , Lesión Renal Aguda/epidemiología , Lesión Renal Aguda/etiología , Lesión Renal Aguda/terapia , Diverticulitis/complicaciones
4.
Surg Endosc ; 37(8): 6097-6106, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37130983

RESUMEN

BACKGROUND: Alvimopan is a µ-opioid receptor antagonist associated with shorter time to gastrointestinal recovery in patients having open colorectal surgery. Data demonstrating the benefit of perioperative alvimopan for the minimally invasive surgical approach are inconsistent. The aim of this study is to determine colorectal surgery groups that benefit from perioperative alvimopan. METHODS: This is a retrospective cohort analysis of colorectal surgery patients who had, and patients who did not have, perioperative alvimopan in the Michigan Surgical Quality Collaborative regional risk-adjusted database from 2018 through 2021. Main outcome measures were postoperative length of hospital stay, time to return of bowel function, and postoperative ileus. RESULTS: There were 10,010 patients (30.3% open, 40.5% laparoscopic, 12.7% hand-assist laparoscopic, 43.5% robotic) who met inclusion criteria-4919 received alvimopan in the perioperative period and 5091 did not. When compared to those not receiving alvimopan, unadjusted outcomes showed that the alvimopan group had significantly shorter postoperative length of stay (4.75 days vs 5.5 days, p < 0.001), shorter time to return of bowel function (1.61 days vs 2.01 days, p < 0.001) and less postoperative ileus (5.45% vs 7.94%, p < 0.001). After adjustment, regression models confirmed that alvimopan was associated with an 9.6% reduction in hospital length of stay (p < 0.001), a 14.9% shorter time to return of bowel function (p < 0.001), and a 42.1% reduction in postoperative ileus (p < 0.001). Subgroup analysis showed significant benefit of alvimopan for all three outcomes in patients having the minimally invasive approach. CONCLUSIONS: Alvimopan is associated with shorter hospital length of stay, shorter time to return of bowel function, and decreased postoperative ileus when administered to patients undergoing colorectal surgery. Benefit is not limited to the open approach and includes minimally invasive laparoscopic and robotic colorectal procedures.


Asunto(s)
Cirugía Colorrectal , Procedimientos Quirúrgicos del Sistema Digestivo , Ileus , Humanos , Estudios Retrospectivos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/tratamiento farmacológico , Ileus/etiología , Ileus/prevención & control , Tiempo de Internación , Fármacos Gastrointestinales/uso terapéutico
5.
Am Surg ; 89(11): 4598-4603, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36039607

RESUMEN

BACKGROUND: Thomboelastography (TEG) is a point of care viscoelastic test that provides an assessment of clot formation and kinetics. Antiplatelet agents are commonly used but there is limited literature evaluating their possible effects on overall clot kinetics. We aimed to evaluate the relationship between antiplatelet agents and clot kinetics as defined by TEG. METHODS: This is a retrospective study of adult patients who underwent TEG from February 2018 to July 2020. Patients who received anticoagulants or blood transfusions within 72 hours, had an incomplete TEG, were diagnosed with COVID-19, or had liver failure were excluded. Patients were stratified based on antiplatelet status. RESULTS: Of 1060 patients, 119 were included (50 controls, 69 antiplatelet agents-37 aspirin monotherapy, 26 dual antiplatelet therapy). Between the control and antiplatelet therapy groups, there was no significant difference in clot time, maximal clot strength, or fibrinogen level. When compared to control patients, patients on dual antiplatelets had significantly higher fibrinogen levels (408.1 mg/dL vs 481.5 mg/dL, P = .013) but no significant differences in clot time or maximal clot strength. In our subgroup analysis, patients on dual antiplatelets had increased maximal clot strength (58.8° vs 63°, P = .005) and fibrinogen levels (384.1 mg/dL vs 481.5 mg/dL, P = .005) compared to those on aspirin alone. DISCUSSION: Compared to control patients and those on aspirin alone, patients on dual antiplatelets have increased maximal clot strength and increased fibrinogen levels. These results can help physicians better target product resuscitation in patients who are on antiplatelet agents.


Asunto(s)
Inhibidores de Agregación Plaquetaria , Trombosis , Adulto , Humanos , Inhibidores de Agregación Plaquetaria/farmacología , Tromboelastografía/métodos , Estudios Retrospectivos , Aspirina/farmacología , Fibrinógeno/análisis
6.
Dis Colon Rectum ; 65(12): 1431-1434, 2022 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-36194654

RESUMEN

CASE SUMMARY: A 33-year-old man with a history of chronic alcohol use, generalized anxiety disorder, and hypertension presented to the emergency department after a syncopal event. He was admitted to the medical intensive care unit for alcohol withdrawal, requiring intubation and sedation. On hospital day 7, abdominal x-ray image demonstrated a dilated cecum to 12 cm, transverse colon dilation to 7 cm, and decompressed distal colon ( Fig. 1 ). CT scan of the abdomen and pelvis confirmed dilation of the cecum and ascending and transverse colons ( Fig. 2 ). Colonoscopy showed no evidence of distal obstruction, but colonic distension persisted, and he subsequently underwent cecal decompression with an open "blow-hole" cecostomy fully matured at skin level via a small right lower quadrant incision. The nasogastric tube was removed on postoperative day 2, and his diet was slowly advanced. Abdominal x-ray image on postoperative day 5 demonstrated no colonic dilation. He was discharged home on postoperative day 7. The patient re-presented to the hospital 3 months later with cecostomy prolapse. He underwent cecostomy takedown with ileocecectomy via circumstomal incision. He was discharged home on postoperative day 2.


Asunto(s)
Alcoholismo , Seudoobstrucción Colónica , Síndrome de Abstinencia a Sustancias , Masculino , Humanos , Adulto , Seudoobstrucción Colónica/diagnóstico , Seudoobstrucción Colónica/etiología , Seudoobstrucción Colónica/cirugía , Cecostomía/métodos , Ciego
7.
BMC Genomics ; 23(1): 160, 2022 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-35209843

RESUMEN

BACKGROUND: Whole genomes are commonly assembled into a collection of scaffolds and often lack annotations of autosomes, sex chromosomes, and organelle genomes (i.e., mitochondrial and chloroplast). As these chromosome types differ in effective population size and can have highly disparate evolutionary histories, it is imperative to take this information into account when analysing genomic variation. Here we assessed the accuracy of four methods for identifying the homogametic sex chromosome in a small population using two whole genome sequences (WGS) and 133 RAD sequences of white-tailed eagles (Haliaeetus albicilla): i) difference in read depth per scaffold in a male and a female, ii) heterozygosity per scaffold in a male and a female, iii) mapping to the reference genome of a related species (chicken) with annotated sex chromosomes, and iv) analysis of SNP-loadings from a principal components analysis (PCA), based on the low-depth RADseq data. RESULTS: The best performing approach was the reference mapping (method iii), which identified 98.12% of the expected homogametic sex chromosome (Z). Read depth per scaffold (method i) identified 86.41% of the homogametic sex chromosome with few false positives. SNP-loading scores (method iv) identified 78.6% of the Z-chromosome and had a false positive discovery rate of more than 10%. Heterozygosity per scaffold (method ii) did not provide clear results due to a lack of diversity in both the Z and autosomal chromosomes, and potential interference from the heterogametic sex chromosome (W). The evaluation of these methods also revealed 10 Mb of putative PAR and gametologous regions. CONCLUSION: Identification of the homogametic sex chromosome in a small population is best accomplished by reference mapping or examining differences in read depth between sexes.


Asunto(s)
Genoma , Cromosomas Sexuales , Animales , Femenino , Genómica , Heterocigoto , Homocigoto , Masculino , Cromosomas Sexuales/genética
8.
Mol Ecol ; 30(13): 3158-3174, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33481325

RESUMEN

Environmental DNA (eDNA) metabarcoding can rapidly characterize the composition and diversity of benthic communities, thus it has high potential utility for routine assessments of benthic impacts of marine finfish farming. In this study, 126 sediment grab samples from 42 stations were collected at six salmon farms in British Columbia, Canada. Benthic community changes were assessed by both eDNA metabarcoding of metazoans and macrofaunal polychaete surveys. The latter was done by analysing 11,466 individuals using a combination of morphology-based taxonomy and DNA barcoding. Study objectives were to: (i) compare biotic signals associated with benthic impacts of salmon farming in the two data sources, and (ii) identify potential eDNA indicators to facilitate monitoring in Canada. Alpha diversity parameters were consistently reduced near fish cage edge and negatively correlated with pore-water sulphide concentration, with coefficients ranging from -0.62 to -0.48. Although Polychaeta are a common indicator group, the negative correlation with pore-water sulphide concentration was much stronger for Nematoda OTU richness (correlation coefficient: -0.86) than for Polychaeta (correlation coefficient: -0.38). Presence/absence of Capitella generally agreed well between the two methods despite that they differed in the volume of sediments sampled and the molecular marker used. Multiple approaches were used to identify OTUs related to organic enrichment statuses. We demonstrate that eDNA metabarcoding generates biotic signals that could be leveraged for environmental assessment of benthic impacts of fish farms in multiple ways: both alpha diversity and Nematoda OTU richness could be used to assess the spatial extent of impact, and OTUs related to organic enrichment could be used to develop local biotic indices.


Asunto(s)
Código de Barras del ADN Taxonómico , Salmón , Animales , Acuicultura , Biodiversidad , Colombia Británica , Monitoreo del Ambiente , Sedimentos Geológicos , Humanos , Salmón/genética
9.
Am Surg ; 87(3): 364-369, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32988226

RESUMEN

INTRODUCTION: The classic findings of acute appendicitis-right lower quadrant pain, anorexia, and leukocytosis-have been well known. However, emergency medicine and surgical providers continue to rely on imaging to confirm the diagnosis. We aimed to evaluate the increase in reliance on computed tomography (CT) scans for acute appendicitis diagnosis over time. METHODS: We conducted a retrospective study of patients ≥18 years presenting to UNC Hospitals with signs and symptoms of acute appendicitis who subsequently underwent appendectomy from 2011 to 2015. Demographic, clinical, laboratory, and pathologic data were reviewed. We evaluated the incidence of CT scans stratified by year, age, and sex. RESULTS: Within our male population, 55.2% (278/504) had classic appendicitis symptoms. Of the 278 male patients with classic appendicitis symptoms, 248 underwent CT imaging. Male patients <45 years of age were more likely to present with classic appendicitis symptoms (216/357, 60.5%) compared with patients aged 46-65 (52/108, 48.1%) or >65 (10/39, 25.6%). Of the male patients <45 years with classic appendicitis symptoms, the incidence of CT scans increased over time (68.3% in 2011, 84.2% in 2012, 92.3% in 2013, 93.9% in 2014, 92.3% in 2015). When considering the 216 CT scans that could have been avoided in our population, we calculate an approximate savings of $173 998.80 over 5 years. CONCLUSION: The incidence of CT scans for acute appendicitis confirmation has increased over time even in men. CT scans for the diagnosis or confirmation of acute appendicitis should rarely be indicated in men aged <45 years with classic appendicitis symptoms.


Asunto(s)
Apendicitis/diagnóstico por imagen , Costos de Hospital/tendencias , Pautas de la Práctica en Medicina/tendencias , Tomografía Computarizada por Rayos X/tendencias , Procedimientos Innecesarios/tendencias , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Apendicectomía , Apendicitis/economía , Apendicitis/cirugía , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pautas de la Práctica en Medicina/economía , Estudios Retrospectivos , Factores Sexuales , Tomografía Computarizada por Rayos X/economía , Estados Unidos , Procedimientos Innecesarios/economía , Adulto Joven
10.
Am Surg ; 85(11): 1209-1212, 2019 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-31775960

RESUMEN

Prompt appendectomy has long been the standard of care for acute appendicitis because of the risk of progression to perforation. Recently, studies have suggested nonemergent management of acute appendicitis. Our study aimed to determine changes in risk of rupture and complications in patients with appendicitis, with increasing time from symptom onset to treatment. Retrospective study of patients aged ≥18 years presenting to the University of North Carolina Hospitals with signs and symptoms of acute appendicitis who subsequently underwent appendectomy from 2011 to 2015 was performed. Demographic, clinical, laboratory, and pathologic data were reviewed. Bivariate analysis was performed to assess variables associated with increased risk of perforation. Poisson regression modeling was completed to evaluate the risk of perforation and postoperative abscess based on time from symptoms to treatment. Within our database of 1007 patients, the mean time from onset of symptoms to operative intervention was 3.24 ± 2.2 days. Modified Poisson regression modeling demonstrated the relative risk for perforation increases by 9% (RR 1.09, P < 0.001) for each day delay. Age (RR 1.03), male gender (RR 1.50), temperature on admission (RR 1.32), and the presence of fecalith (RR 1.89) statistically significantly increased the risk of perforation. Furthermore, for each day delay, there is an 8% increased risk of postoperative abscess (RR 1.08, P = 0.027). The relative risk for appendiceal perforation is 9 per cent per day delay with a resultant 8 per cent increased risk of postoperative abscess. Thus, appendectomy for acute appendicitis should remain an emergent procedure, given that delays in operative management lead to complications and increases in cost of care.


Asunto(s)
Absceso/etiología , Apendicitis/complicaciones , Apendicitis/cirugía , Perforación Intestinal/etiología , Enfermedad Aguda , Adulto , Factores de Edad , Temperatura Corporal , Estudios de Casos y Controles , Urgencias Médicas , Impactación Fecal/complicaciones , Femenino , Humanos , Masculino , Persona de Mediana Edad , Distribución de Poisson , Estudios Retrospectivos , Factores de Riesgo , Rotura Espontánea/etiología , Factores Sexuales , Tiempo de Tratamiento
11.
Am Surg ; 85(2): 223-225, 2019 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-30819303

RESUMEN

One potential harm of nonoperative management for acute appendicitis is missed appendiceal cancer, a rare and often aggressive malignancy due to the frequency of late stage of diagnosis. Previous studies have reported an increasing incidence of appendiceal neoplasms in the population. This is a retrospective case-control study of 1007 adult patients, who presented to the University of North Carolina-Memorial Hospital (UNC-MH) between 2011 and 2015 with clinical signs and symptoms of appendicitis. We evaluated the incidence of primary appendiceal cancer in this population and determined factors that predict appendiceal cancer diagnosis using multivariate logistic regression analysis. The overall incidence of appendiceal neoplasm for adult patients presenting to UNC-MH with appendicitis from 2011 to 2015 was 2.3 per cent (23/1007). The incidence in patients without appendiceal perforation on pathology was 1.9 per cent (16/832). Age (odds ratio (OR) 1.03), number of days of abdominal pain (OR 1.16), self-reported fever (OR 2.08), appendiceal width (OR 1.95), and appendiceal wall thickness (OR 1.30) were predictors of appendiceal neoplasm diagnosis in patients that present with acute appendicitis. We recommend that an operative approach to acute appendicitis should remain the standard of care because operative management may not only be diagnostic but potentially therapeutic.


Asunto(s)
Neoplasias del Apéndice/diagnóstico , Neoplasias del Apéndice/epidemiología , Apendicitis/patología , Apendicitis/terapia , Adulto , Factores de Edad , Apendicectomía , Femenino , Humanos , Incidencia , Modelos Logísticos , Masculino , Estudios Retrospectivos , Factores de Riesgo
12.
Ecol Evol ; 8(9): 4552-4563, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29760896

RESUMEN

Geographical patterns in morphology can be the result of divergence among populations due to neutral or selective changes and/or phenotypic plasticity in response to different environments. Marine gastropods are ideal subjects on which to explore these patterns, by virtue of the remarkable intraspecific variation in life-history traits and morphology often observed across relatively small spatial scales. The ubiquitous N-Atlantic common whelk (Buccinum undatum) is well known for spatial variation in life-history traits and morphology. Previous studies on genetic population structure have revealed that it exhibits significant differentiation across geographic distances. Within Breiðafjörður Bay, a large and shallow bay in W-Iceland, genetic differentiation was demonstrated between whelks from sites separated by just 20 km. Here, we extended our previous studies on the common whelk in Breiðafjörður Bay by quantifying phenotypic variation in shell morphology and color throughout the Bay. We sought to test whether trait differentiation is dependent on geographic distance and/or environmental variability. Whelk in Breiðafjörður Bay displayed fine-scale patterns of spatial variation in shape, thickness, and color diversity. Differentiation increased with increasing distance between populations, indicating that population connectivity is limited. Both shape and color varied along a gradient from the inner part of the bay in the east to the outer part in the west. Whelk shells in the innermost part of Breiðafjörður Bay were thick with an elongate shell, round aperture, and low color diversity, whereas in the outer part of the bay the shells were thinner, rounder, with a more elongate aperture and richer color diversity. Significant site-specific difference in shell traits of the common whelk in correlation with environmental variables indicates the presence of local ecotypes and limited demographic connectivity.

13.
Ecol Evol ; 7(12): 4326-4335, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28649344

RESUMEN

Macrobrachium rosenbergii, the giant freshwater prawn, is an important source of high quality protein and occurs naturally in rivers as well as commercial farms in South and South-East Asia, including Bangladesh. This study investigated the genetic variation and population structure of M. rosenbergii sampled from four rivers in Bangladesh (sample size ranged from 19 to 20), assessing sequence variation, both in the mitochondrial cytochrome oxidase subunit 1 (CO1) gene and in 106 single nucleotide polymorphisms (SNPs) sampled randomly from the genome with double digest RAD sequencing (ddRADseq). The mitochondrial variation presented a shallow genealogy with high haplotype diversity (h = 0.95), reflecting an expansion in population size for the last ~82 kyr. Based on the CO1 variation the current effective population size (Ne) was 9.7 × 106 (CI: 1.33 × 106 - 35.84 × 106) individuals. A significant population differentiation was observed with the mitochondrial CO1 sequence variation and based on the ddRADseq variation, which could be traced to the divergence of the population in the Naf River in the South-East border with Myanmar from the other populations. A differentiation in mtDNA haplotype frequencies was also observed between the Biskhali River and the Karnaphuli Rivers in eastern Bangladesh. This study demonstrated the use of high-throughput genotyping based on the ddRADseq method to reveal population structure at a small geographical scale for an important freshwater prawn. The information from this study can be utilized for management and conservation of this species in Bangladesh.

14.
Glob Chang Biol ; 22(9): 3182-95, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27124277

RESUMEN

Human-mediated biological transfers of species have substantially modified many ecosystems with profound environmental and economic consequences. However, in many cases, invasion events are very hard to identify because of the absence of an appropriate baseline of information for receiving sites/regions. In this study, use of high-resolution genetic markers (single nucleotide polymorphisms - SNPs) highlights the threat of introduced Northern Hemisphere blue mussels (Mytilus galloprovincialis) at a regional scale to Southern Hemisphere lineages of blue mussels via hybridization and introgression. Analysis of a multispecies SNP dataset reveals hotspots of invasive Northern Hemisphere blue mussels in some mainland New Zealand locations, as well as the existence of unique native lineages of blue mussels on remote oceanic islands in the Southern Ocean that are now threatened by invasive mussels. Samples collected from an oil rig that has moved between South Africa, Australia, and New Zealand were identified as invasive Northern Hemisphere mussels, revealing the relative ease with which such non-native species may be moved from region to region. In combination, our results highlight the existence of unique lineages of mussels (and by extension, presumably of other taxa) on remote offshore islands in the Southern Ocean, the need for more baseline data to help identify bioinvasion events, the ongoing threat of hybridization and introgression posed by invasive species, and the need for greater protection of some of the world's last great remote areas.


Asunto(s)
Variación Genética , Especies Introducidas , Mytilus edulis , Animales , Australia , Nueva Zelanda , Océanos y Mares , Sudáfrica
15.
Proc Biol Sci ; 281(1777): 20132976, 2014 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-24403343

RESUMEN

Atlantic cod (Gadus morhua) vertebrae from archaeological sites were used to study the history of the Icelandic Atlantic cod population in the time period of 1500-1990. Specifically, we used coalescence modelling to estimate population size and fluctuations from the sequence diversity at the cytochrome b (cytb) and Pantophysin I (PanI) loci. The models are consistent with an expanding population during the warm medieval period, large historical effective population size (NE), a marked bottleneck event at 1400-1500 and a decrease in NE in early modern times. The model results are corroborated by the reduction of haplotype and nucleotide variation over time and pairwise population distance as a significant portion of nucleotide variation partitioned across the 1550 time mark. The mean age of the historical fished stock is high in medieval times with a truncation in age in early modern times. The population size crash coincides with a period of known cooling in the North Atlantic, and we conclude that the collapse may be related to climate or climate-induced ecosystem change.


Asunto(s)
Gadus morhua/clasificación , Gadus morhua/genética , Proteínas Mitocondriales/genética , Animales , Clima , Citocromos b/genética , Citocromos b/metabolismo , Demografía , Ecosistema , Proteínas de Peces/genética , Proteínas de Peces/metabolismo , Gadus morhua/fisiología , Islandia , Proteínas Mitocondriales/metabolismo , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Dinámica Poblacional , Análisis de Secuencia de ADN , Columna Vertebral/química , Sinaptofisina/genética , Sinaptofisina/metabolismo , Factores de Tiempo
16.
Cardiovasc Res ; 89(3): 604-13, 2011 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-21088116

RESUMEN

AIMS: Obesity and hyperlipidaemia are associated with insulin resistance (IR); however, the mechanisms responsible remain incompletely understood. Pro-atherogenic hyperlipidaemic states are characterized by inflammation, oxidant stress, and pathophysiologic oxidized lipids, including ligands for the scavenger receptor CD36. Here we tested the hypothesis that the absence of CD36 protects mice from IR associated with diet-induced obesity and hyperlipidaemia. METHODS AND RESULTS: Adipose tissue from CD36(-/-) mice demonstrated a less inflammatory phenotype and improved insulin signalling in vivo and at the level of the adipocyte and macrophage. The pathophysiologic ligand oxidized low-density lipoprotein (oxLDL) activated c-Jun N-terminal kinase (JNK) and disrupted insulin signalling in both adipocytes and macrophages in a CD36-dependent manner. Macrophages isolated from CD36(-/-) mice after high-fat diet feeding elicited less JNK activation and inhibition of insulin signalling in adipocytes after co-culture compared with wild-type macrophages. CONCLUSION: These data suggest that a CD36-dependent inflammatory paracrine loop between adipocytes and macrophages facilitates chronic inflammation and contributes to IR common in obesity and dyslipidaemia.


Asunto(s)
Tejido Adiposo/inmunología , Antígenos CD36/metabolismo , Inflamación/metabolismo , Insulina/metabolismo , Macrófagos/metabolismo , Transducción de Señal/inmunología , Adipocitos/citología , Adipocitos/inmunología , Adipocitos/metabolismo , Tejido Adiposo/citología , Tejido Adiposo/metabolismo , Animales , Antígenos CD36/genética , Antígenos CD36/inmunología , Células Cultivadas , Técnicas de Cocultivo , Dislipidemias/inmunología , Dislipidemias/metabolismo , Femenino , Intolerancia a la Glucosa/inmunología , Intolerancia a la Glucosa/metabolismo , Inflamación/inmunología , Resistencia a la Insulina/inmunología , Lipoproteínas LDL/metabolismo , Macrófagos/citología , Macrófagos/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , Obesidad/inmunología , Obesidad/metabolismo
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