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1.
Appl Environ Microbiol ; 88(17): e0092922, 2022 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-35950875

RESUMEN

Alkaline fluids venting from chimneys of the Lost City hydrothermal field flow from a potentially vast microbial habitat within the seafloor where energy and organic molecules are released by chemical reactions within rocks uplifted from Earth's mantle. In this study, we investigated hydrothermal fluids venting from Lost City chimneys as windows into subseafloor environments where the products of geochemical reactions, such as molecular hydrogen (H2), formate, and methane, may be the only available sources of energy for biological activity. Our deep sequencing of metagenomes and metatranscriptomes from these hydrothermal fluids revealed a few key species of archaea and bacteria that are likely to play critical roles in the subseafloor microbial ecosystem. We identified a population of Thermodesulfovibrionales (belonging to phylum Nitrospirota) as a prevalent sulfate-reducing bacterium that may be responsible for much of the consumption of H2 and sulfate in Lost City fluids. Metagenome-assembled genomes (MAGs) classified as Methanosarcinaceae and Candidatus Bipolaricaulota were also recovered from venting fluids and represent potential methanogenic and acetogenic members of the subseafloor ecosystem. These genomes share novel hydrogenases and formate dehydrogenase-like sequences that may be unique to hydrothermal environments where H2 and formate are much more abundant than carbon dioxide. The results of this study include multiple examples of metabolic strategies that appear to be advantageous in hydrothermal and subsurface alkaline environments where energy and carbon are provided by geochemical reactions. IMPORTANCE The Lost City hydrothermal field is an iconic example of a microbial ecosystem fueled by energy and carbon from Earth's mantle. Uplift of mantle rocks into the seafloor can trigger a process known as serpentinization that releases molecular hydrogen (H2) and creates unusual environmental conditions where simple organic carbon molecules are more stable than dissolved inorganic carbon. This study provides an initial glimpse into the kinds of microbes that live deep within the seafloor where serpentinization takes place, by sampling hydrothermal fluids exiting from the Lost City chimneys. The metabolic strategies that these microbes appear to be using are also shared by microbes that inhabit other sites of serpentinization, including continental subsurface environments and natural springs. Therefore, the results of this study contribute to a broader, interdisciplinary effort to understand the general principles and mechanisms by which serpentinization-associated processes can support life on Earth and perhaps other worlds.


Asunto(s)
Ecosistema , Respiraderos Hidrotermales , Archaea/genética , Archaea/metabolismo , Bacterias/genética , Bacterias/metabolismo , Formiatos/metabolismo , Hidrógeno/metabolismo , Respiraderos Hidrotermales/microbiología , Sulfatos/metabolismo
2.
Phys Rev Lett ; 114(3): 031102, 2015 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-25658989

RESUMEN

Nuclear pasta, with nonspherical shapes, is expected near the base of the crust in neutron stars. Large-scale molecular dynamics simulations of pasta show long lived topological defects that could increase electron scattering and reduce both the thermal and electrical conductivities. We model a possible low-conductivity pasta layer by increasing an impurity parameter Q_{imp}. Predictions of light curves for the low-mass x-ray binary MXB 1659-29, assuming a large Q_{imp}, find continued late time cooling that is consistent with Chandra observations. The electrical and thermal conductivities are likely related. Therefore, observations of late time crust cooling can provide insight on the electrical conductivity and the possible decay of neutron star magnetic fields (assuming these are supported by currents in the crust).

3.
Clin Anat ; 27(2): 234-40, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23959791

RESUMEN

Biomechanical models predict that recruitment of gluteus maximus (GMax) will exert a compressive force across the sacroiliac joint (SIJ), yet this muscle requires morphologic assessment. The aims of this study were to document GMax's proximal attachments and assess their capacity to generate forces including compressive force at the SIJ. In 11 embalmed cadaver limbs, attachments of GMax crossing the SIJ were dissected and their fascicle orientation, length and attachment volume documented. The physiological cross-sectional area (PCSA) of each attachment was calculated along with its estimated maximum force at the SIJ and lumbar spine. GMax fascicles originated from the gluteus medius fascia, ilium, thoracolumbar fascia, erector spinae aponeurosis, sacrum, coccyx, dorsal sacroiliac and sacrotuberous ligaments in all specimens. Their mean fascicle orientation ranged from 32 to 45° below horizontal and mean length from 11 to 18 cm. The mean total PCSA of GMax was 26 cm(2) (range 16-36), of which 70% crossed the SIJ. The average maximum force predicted to be generated by GMax's total attachments crossing each SIJ was 891 N (range 572-1,215), of which 70% (702 N: range 450-1,009) could act perpendicular to the plane of the SIJ. The capacity of GMax to generate an extensor moment at lower lumbar segments was estimated at 4 Nm (range 2-9.5). GMax may generate compressive forces at the SIJ through its bony and fibrous attachments. These may assist effective load transfer between lower limbs and trunk.


Asunto(s)
Fascia/anatomía & histología , Cadera/anatomía & histología , Vértebras Lumbares/anatomía & histología , Músculo Esquelético/anatomía & histología , Articulación Sacroiliaca/anatomía & histología , Vértebras Torácicas/anatomía & histología , Anciano , Anciano de 80 o más Años , Fenómenos Biomecánicos/fisiología , Cadáver , Fascia/fisiología , Femenino , Cadera/fisiología , Humanos , Vértebras Lumbares/fisiología , Masculino , Persona de Mediana Edad , Modelos Anatómicos , Modelos Biológicos , Músculo Esquelético/fisiología , Articulación Sacroiliaca/fisiología , Vértebras Torácicas/fisiología
4.
Hernia ; 28(1): 3-7, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37597106

RESUMEN

PURPOSE: Utilisation of remote clinics is increasing in healthcare settings worldwide. During the height of the COVID pandemic, our UK-based teaching hospital has trialled telephone assessment for new patients presenting with primary hernias. Selected cases are listed for elective repair of primary hernia direct from telephone clinic assessment. In March 2021, after this process had been in place for 13 months, departmental triage criteria were introduced, allocating patients to initial assessment in Face to Face or Telephone Clinics. Here, we evaluate the effectiveness of telephone assessment, with specific attention to 'Day of Surgery' cancellation. We also assess the effect of our triage criteria on rate of 'Day of Surgery' cancellation. METHODS: Departmental diaries were studied retrospectively to identify patients listed for hernia repair between February 2020 and February 2022. Data were obtained from clinic letters, discharge paperwork and operating lists, as well as from management teams. Fishers Exact test was used to compare groups seen either face to face or remotely as well and pre- and post-intervention. RESULTS: 325 patients were listed for hernia repair, 56 after telephone assessment. 6 (11%) of those listed from telephone clinic were cancelled on the day of surgery, compared with 34 (13%) of those seen face to face. With triage criteria in place, listing from telephone clinic increased significantly from 14 to 27%. Overall day of surgery cancellations reduced from 13 to 9%. Rate of day of surgery cancellation in those assessed in telephone clinic reduced from 12 to 9%. CONCLUSIONS: There is no significant difference between day of surgery cancellations after face to face or telephone clinic assessment. Triage criteria for telephone assessment appear to increase the numbers being listed after remote clinics. This did not significantly impact the number of day of surgery cancellations.


Asunto(s)
Procedimientos Quirúrgicos Electivos , Herniorrafia , Humanos , Estudios Retrospectivos , Derivación y Consulta , Teléfono , Hernia
5.
PLoS One ; 19(5): e0284642, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38718041

RESUMEN

The GO DNA repair system protects against GC → TA mutations by finding and removing oxidized guanine. The system is mechanistically well understood but its origins are unknown. We searched metagenomes and abundantly found the genes encoding GO DNA repair at the Lost City Hydrothermal Field (LCHF). We recombinantly expressed the final enzyme in the system to show MutY homologs function to suppress mutations. Microbes at the LCHF thrive without sunlight, fueled by the products of geochemical transformations of seafloor rocks, under conditions believed to resemble a young Earth. High levels of the reductant H2 and low levels of O2 in this environment raise the question, why are resident microbes equipped to repair damage caused by oxidative stress? MutY genes could be assigned to metagenome-assembled genomes (MAGs), and thereby associate GO DNA repair with metabolic pathways that generate reactive oxygen, nitrogen and sulfur species. Our results indicate that cell-based life was under evolutionary pressure to cope with oxidized guanine well before O2 levels rose following the great oxidation event.


Asunto(s)
Reparación del ADN , Guanina , Metagenoma , Oxidación-Reducción , Guanina/metabolismo , Respiraderos Hidrotermales/microbiología
6.
Clin Anat ; 26(2): 244-52, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22374796

RESUMEN

Guidelines for assessing the function of gluteus minimus and gluteus medius with electromyography (EMG) traditionally offer one electrode placement site per muscle. However, anatomical studies suggest that there are two uniquely oriented segments within gluteus minimus (anterior and posterior), and three within gluteus medius (anterior, middle, and posterior) with potential for independent function. Assessment of these muscles with one electrode may therefore provide only a limited account of their role. Thus, the aim of this cadaveric study was to verify guidelines for placing intramuscular electrodes into two uniquely oriented segments of gluteus minimus, and three segments of gluteus medius. The guidelines were developed with reference to anatomical reports, cadaveric observation and real-time ultrasound imaging in vivo. Five cadaveric gluteal regions were marked for intramuscular electrode insertions based on these guidelines. Intramuscular electrodes were inserted into the marked regions of gluteus minimus (2×) and gluteus medius (3×) with the aid of a 15 cm biopsy needle. Systematic dissection revealed that electrodes were successfully inserted into uniquely oriented segments of gluteus minimus and medius. The orientation of fascicles surrounding each electrode was also consistent with segmental descriptions in past anatomical research. The findings of this research suggest that the guidelines described may be used to assess the functional role of segments within gluteus minimus and medius in health and dysfunction using EMG. Finally, electromyographers intent on investigating the role of posterior gluteus minimus must be cautious of the superior gluteal neurovascular bundle.


Asunto(s)
Electromiografía/métodos , Músculo Esquelético/fisiología , Anciano de 80 o más Años , Nalgas , Electrodos , Electromiografía/normas , Femenino , Guías como Asunto , Humanos , Masculino
7.
Ann R Coll Surg Engl ; 105(5): 446-454, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-35904332

RESUMEN

BACKGROUND/AIMS: A tissue diagnosis is not always obtained prior to pancreatoduodenectomy (PD) and a proportion of patients are found to have noncancerous histology postoperatively. It is unknown if these patients have different outcomes when compared with those who have malignancy confirmed. METHODS: A retrospective paired case matched control study was undertaken. Patients who underwent PD for suspected malignancy but ultimately had nonmalignant histology were identified. Each was matched to a confirmed malignant control using the following criteria: age, gender, body mass index, American Society of Anesthesiologists grade, neoadjuvant treatment, preoperative serum bilirubin, preoperative biliary stenting and type of pancreatic anastomosis. Matching was blinded to the measured outcomes, which included perioperative morbidity and mortality. RESULTS: Forty-five cases were compared with 45 well-matched controls. There was no difference in 30- or 90-day mortality, or length of stay. While overall morbidity rates were the same, patients with nonmalignant disease were more likely to experience major (Clavien-Dindo grade III-IV) morbidity (40.0% versus 17.8%, p = 0.0352). Independently, rates of clinically relevant pancreatic fistula (CR-POPF) were higher in the nonmalignant group (22.2% versus 4.44%, p = 0.0131). CONCLUSIONS: In our study, PD patients with nonmalignant histology had significantly higher incidence of major morbidity and CR-POPF when compared with those who had malignancy confirmed. This should be considered when planning the management of patients with known or presumed benign/premalignant disease.


Asunto(s)
Pancreaticoduodenectomía , Complicaciones Posoperatorias , Humanos , Pancreaticoduodenectomía/efectos adversos , Estudios Retrospectivos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía , Páncreas/patología , Fístula Pancreática/epidemiología , Fístula Pancreática/etiología , Fístula Pancreática/cirugía , Incidencia , Factores de Riesgo
8.
J Evol Biol ; 24(10): 2258-68, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21767320

RESUMEN

We examine the maintenance of a plumage polymorphism, variation in plumages among the same age and sex class within a population, in a population of Swainson's Hawks. We take advantage of 32 years of data to examine two prevalent hypotheses used to explain the persistence of morphs: apostatic selection and heterozygous advantage. We investigate differences in fitness among three morph classes of a melanistic trait in Swainson's Hawks: light (7% of the local breeding population), intermediate (57%) and dark (36%). Specifically, we examined morph differences in adult apparent survival, breeding success, annual number of fledglings produced, probability of offspring recruitment into the breeding population and lifetime reproductive success (LRS). If apostatic selection were a factor in maintaining morphs, we would expect that individuals with the least frequent morph would perform best in one or more of these fitness categories. Alternatively, if heterozygous advantage played a role in the maintenance of this polymorphism, we would expect heterozygotes (i.e. intermediate morphs) to have one or more increased rates in these categories. We found no difference in adult apparent survival between morph classes. Similarly, there were no differences in breeding success, nest productivity, LRS or probability of recruitment of offspring between parental morph. We conclude that neither apostatic selection nor heterozygous advantage appear to play a role in maintaining morphs in this population.


Asunto(s)
Plumas/anatomía & histología , Halcones/fisiología , Modelos Biológicos , Animales , Femenino , Halcones/anatomía & histología , Longevidad , Masculino , Reproducción , Conducta Sexual Animal
9.
J Med Entomol ; 48(1): 20-8, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21337944

RESUMEN

The abiotic and biotic factors that govern the spatial distribution of Lyme disease vectors are poorly understood. This study addressed the influence of abiotic and biotic environmental variables on Ixodes pacificus Cooley & Kohls (Acari:Ixodidae) nymphs, because it is the primary vector of Borrelia burgdorferi Johnson, Schmidt, Hyde, Steigerwaldt & Brenner in the far-western United States. Three metrics of Lyme disease risk were evaluated: the density of nymphs, the density of infected nymphs, and the nymphal infection prevalence. This study sampled randomly located plots in oak (Quercus spp.) woodland habitat in Sonoma County, CA. Each plot was drag-sampled for nymphal ticks and tested for B. burgdorferi infection. Path analysis was used to evaluate the direct and indirect relationship between topographic, forest structure and microclimatic variables on ticks. Significant negative correlations were found between maximum temperature in the dry season and the density of infected ticks in 2006 and tick density in 2007, but we did not find a significant relationship with nymphal infection prevalence in either year. Tick density and infected tick density had an indirect, positive correlation with elevation, mediated through temperature. This study found that in certain years but not others, temperature maxima in the dry season may constrain the density and density of infected I. pacificus nymphs. In other years, biotic or stochastic factors may play a more important role in determining tick density.


Asunto(s)
Borrelia burgdorferi/fisiología , Ecosistema , Interacciones Huésped-Patógeno , Ixodes/microbiología , Microclima , Animales , California , Densidad de Población , Quercus
10.
West Afr J Med ; 30(2): 84-8, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21984453

RESUMEN

BACKGROUND: Maternal death and disability remain significant problems in developing countries and are predominantly caused by preeclampsia and postpartum haemorrhage. The diagnostic criteria for preeclampsia and postpartum haemorrhage require medical technologies not readily available in underdeveloped areas. OBJECTIVE: To determine the correlates of pre-eclampsia and postpartum haemorrhage using symptoms in a rural setting. METHODS: This was a cross-sectional study in which 577 women from the Kwahu South District of the Eastern Region of Ghana completed questionnaires that sought for signs and symptoms of pre-eclampsia and postpartum haemorrhage in their current or prior pregnancies. The study was conducted over a period of two months, symptoms of pre-eclampsia assessed included headache, visual disturbance, urination, breathing, leg swelling and seizures. For postpartum haemorrhage, the following features were assessed: placenta delivery, length of labour, difficult delivery of placenta, lacerations associated with delivery, size of newborn, headache, visual disturbance and amount of vaginal bleeding. RESULTS: There was a significant association between education and the number of signs and symptoms of preeclampsia, (Χ² =9.059, =0.018; OR no education vs >7 years=6.8). Mothers with no education were about seven times more likely to have all six signs and symptoms of preeclampsia than those with seven or more years of education. There was no significant association between education and postpartum haemorrhage, (Χ² = 1.835, = 0.400). However, the OR of 1.59, indicated an inverse association between the two variables. CONCLUSION: The high number of symptoms associated with preeclampsia among women with no formal education strongly supports the need for educational outreach and basic prenatal care in rural Ghana.


Asunto(s)
Hemorragia Posparto/epidemiología , Preeclampsia/epidemiología , Estudios Transversales , Parto Obstétrico/estadística & datos numéricos , Femenino , Ghana/epidemiología , Cefalea , Humanos , Incidencia , Mortalidad Materna , Hemorragia Posparto/diagnóstico , Periodo Posparto , Preeclampsia/diagnóstico , Embarazo , Atención Prenatal , Factores de Riesgo , Población Rural , Factores Socioeconómicos , Encuestas y Cuestionarios
11.
Scand J Med Sci Sports ; 20(4): 580-7, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19706004

RESUMEN

Iliotibial band (ITB) syndrome (ITBS) is a common cause of distal lateral thigh pain in athletes. Treatment often focuses on stretching the ITB and treating local inflammation at the lateral femoral condyle (LFC). We examine the area's anatomical and biomechanical properties. Anatomical studies of the ITB of 20 embalmed cadavers. The strain generated in the ITB by three typical stretching maneuvers (Ober test; Hip flexion, adduction and external rotation, with added knee flexion and straight leg raise to 30 degrees ) was measured in five unembalmed cadavers using strain gauges. Displacement of the Tensae Fasciae Latae (TFL)/ITB junction was measured on 20 subjects during isometric hip abduction. The ITB was uniformly a lateral thickening of the circumferential fascia lata, firmly attached along the linea aspera (femur) from greater trochanter up to and including the LFC. The microstrain values [median (IQR)] for the OBER [15.4(5.1-23.3)me], HIP [21.1(15.6-44.6)me] and SLR [9.4(5.1-10.7)me] showed marked disparity in the optimal inter-limb stretching protocol. HIP stretch invoked significantly (Z=2.10, P=0.036) greater strain than the SLR. TFL/ITB junction displacement was 2.0+/-1.6 mm and mean ITB lengthening was <0.5% (effect size=0.04). Our results challenge the reasoning behind a number of accepted means of treating ITBS. Future research must focus on stretching and lengthening the muscular component of the ITB/TFL complex.


Asunto(s)
Medicina Basada en la Evidencia , Fascia Lata/fisiopatología , Manejo del Dolor , Anciano , Anciano de 80 o más Años , Fenómenos Biomecánicos , Cadáver , Fascia Lata/anatomía & histología , Femenino , Humanos , Masculino , Síndrome
12.
Scand J Surg ; 109(3): 211-218, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31131722

RESUMEN

BACKGROUND: The benefits of laparoscopic hemi-hepatectomy compared to open hemi-hepatectomy are not clear. OBJECTIVE: This study aims to share our experience with the laparoscopic hemi-hepatectomy compared to an open approach. METHODS: A total of 40 consecutive laparoscopically started hemi-hepatectomy (intention-to-treat analysis) cases between August 2012 and October 2015 were matched against open cases using the following criteria: laterality of surgery and pathology (essential criteria); American Society of Anesthesiologists score, body mass index, pre-operative bilirubin, neo-adjuvant chemotherapy, additional procedures, portal vein embolization, and presence of cirrhosis/fibrosis on histology (secondary criteria); age and gender (tertiary criteria). Hand-assisted and extended hemi-hepatectomy cases were excluded from the study. The two groups were compared for blood loss, operative time, hospital stay, morbidity, mortality, and oncological outcomes. All complications were quantified using the Clavien-Dindo classification. RESULTS: Two groups were well matched (p = 1.00). In the two groups, 10 patients had left and 30 had right hemi-hepatectomy. Overall conversion rate was 15%. Median length of hospital and high dependency unit stay was less in the intention to treat laparoscopic hemi-hepatectomy group: 6 versus 8 days, p = 0.025 and 1 versus 2 days, p = 0.07. Median operative time was longer in the intention to treat laparoscopic hemi-hepatectomy group: 420 min (range: 389.5-480) versus 305 min (range: 238.8-348.8; p = 0.001). Intra-operative blood loss was equivalent, but the overall blood transfusions were higher in the intention to treat laparoscopic hemi-hepatectomy (50 vs 29 units, p = 0.36). The overall morbidity (18 vs 20 patients, p = 0.65), mortality (2.5%), and the positive resection margin status were similar (18% vs 21%, p = 0.76). The 1- (87.5% vs 92.5%, p = 0.71) and 3-year survival (70% vs 72.5%, p = 1.00) was also similar. CONCLUSIONS: We observed lower hospital and high dependency unit stay in the laparoscopic group. However, the laparoscopic approach was associated with longer operating time and a non-significant increase in blood transfusion requirements. There was no difference in morbidity, mortality, re-admission rate, and oncological outcomes.


Asunto(s)
Hepatectomía/métodos , Laparoscopía , Anciano , Pérdida de Sangre Quirúrgica/estadística & datos numéricos , Femenino , Hepatectomía/mortalidad , Humanos , Análisis de Intención de Tratar , Estimación de Kaplan-Meier , Tiempo de Internación/estadística & datos numéricos , Masculino , Análisis por Apareamiento , Persona de Mediana Edad , Tempo Operativo , Evaluación de Resultado en la Atención de Salud , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Estudios Retrospectivos
13.
Br J Pharmacol ; 153(5): 1054-61, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18157163

RESUMEN

BACKGROUND AND PURPOSE: The alpha7 nicotinic acetylcholine receptor (nAChR) has attracted considerable interest as a target for cognitive enhancement in schizophrenia and Alzheimer's Disease. However, most recently described alpha7 agonists are derived from the quinuclidine structural class. Alternatively, the present study identifies tilorone as a novel alpha7-selective agonist and characterizes analogues developed from this lead. EXPERIMENTAL APPROACH: Activity and selectivity were determined from rat brain alpha7 and alpha4beta2 nAChR binding, recombinant nAChR activation, and native alpha7 nAChR mediated stimulation of ERK1/2 phosphorylation in PC12 cells. KEY RESULTS: Tilorone bound alpha7 nAChR (IC(50) 110 nM) with high selectivity relative to alpha4beta2 (IC(50) 70 000 nM), activated human alpha7 nAChR with an EC(50) value of 2.5 microM and maximal response of 67% relative to acetylcholine, and showed little agonist effect at human alpha3beta4 or alpha4beta2 nAChRs. However, the rat alpha7 nAChR maximal response was only 34%. Lead optimization led to 2-(5-methyl-hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-xanthen-9-one (A-844606) with improved binding (alpha7 IC(50) 11 nM, alpha4beta2 IC(50)>30 000 nM) and activity at both human and rat alpha7 nAChR (EC(50)s 1.4 and 2.2 microM and apparent efficacies 61 and 63%, respectively). These compounds also activated native alpha7 nAChR, stimulating ERK1/2 phosphorylation in PC12 cells. CONCLUSIONS AND IMPLICATIONS: Tilorone, known as an interferon inducer, is a selective alpha7 nAChR agonist, suggesting utility of the fluorenone pharmacophore for the development of alpha7 nAChR selective agonists. Whether alpha7 stimulation mediates interferon induction, or whether interferon induction may influence the potential anti-inflammatory properties of alpha7 nAChR agonists remains to be elucidated.


Asunto(s)
Antiinflamatorios/farmacología , Pirroles/farmacología , Receptores Nicotínicos/efectos de los fármacos , Tilorona/farmacología , Xantonas/farmacología , Animales , Antiinflamatorios/administración & dosificación , Encéfalo/metabolismo , Relación Dosis-Respuesta a Droga , Humanos , Concentración 50 Inhibidora , Proteína Quinasa 1 Activada por Mitógenos/efectos de los fármacos , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/efectos de los fármacos , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Células PC12 , Fosforilación/efectos de los fármacos , Unión Proteica , Pirroles/administración & dosificación , Ratas , Receptores Nicotínicos/metabolismo , Tilorona/administración & dosificación , Tilorona/análogos & derivados , Xantonas/administración & dosificación , Receptor Nicotínico de Acetilcolina alfa 7
14.
Environ Entomol ; 36(2): 441-50, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17445380

RESUMEN

This study assessed the influence of microenvironment on the establishment and relative reproductive success of the gall-forming midge Rhopalomyia californica Felt on its host plant Baccharis pilularis De Candolle in Marin County, CA. Mesh cages were used to alter the microenvironment, which also allowed us to assess the validity of using these types of experimental manipulations in this system. Temperature, light intensity, wind speed, and stem growth were compared in caged and uncaged B. pilularis plots in two sites during three seasons. Cage presence significantly altered the microenvironment of R. californica but did not affect development. R. californica establishment was greater when growing on host plants with increased stem growth. Season had the largest impact on gall establishment and reproductive success, with the highest establishment and success rates in late winter to early spring, which correlated with the growing period of B. pilularis. These results suggest that the seasonality of R. californica reproductive success is linked to the phenology of its host plant. When the growing conditions for the plant are less than ideal, R. californica performance is stimulated by increased stem growth. Cage presence was not a significant driver of population dynamics because it did not change the environment in an ecologically meaningful way. We therefore assert that the use of cages for experimental manipulations in this study system does not alter R. californica performance.


Asunto(s)
Baccharis/parasitología , Dípteros/crecimiento & desarrollo , Ambiente , Reproducción/fisiología , Animales , California , Dinámica Poblacional , Estaciones del Año , Especificidad de la Especie , Temperatura , Viento
15.
Perioper Med (Lond) ; 6: 22, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29204270

RESUMEN

BACKGROUND: Risk prediction techniques commonly used in liver surgery include the American Society of Anesthesiologists (ASA) grading, Charlson Comorbidity Index (CCI) and cardiopulmonary exercise tests (CPET). This study compares the utility of these techniques along with the number of segments resected as predictive tools in liver surgery. METHODS: A review of a unit database of patients undergoing liver resection between February 2008 and January 2015 was undertaken. Patient demographics, ASA, CCI and CPET variables were recorded along with resection size. Clavien-Dindo grade III-V complications were used as a composite outcome in analyses. Association between predictive variables and outcome was assessed by univariate and multivariate techniques. RESULTS: One hundred and seventy-two resections in 168 patients were identified. Grade III-V complications occurred after 42 (24.4%) liver resections. In univariate analysis of CPET variables, ventilatory equivalents for CO2 (VEqCO2) was associated with outcome. CCI score, but not ASA grade, was also associated with outcome. In multivariate analysis, the odds ratio of developing grade III-V complications for incremental increases in VEqCO2, CCI and number of liver segments resected were 1.09, 1.49 and 2.94, respectively. CONCLUSIONS: Of the techniques evaluated, resection size provides the simplest and most discriminating predictor of significant complications following liver surgery.

16.
Cochrane Database Syst Rev ; (2): CD003318, 2006 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-16625576

RESUMEN

BACKGROUND: Strategies to integrate primary health care aim to bring together inputs, organisation, management and delivery of particular service functions to make them more efficient, and accessible to the service user. In some middle and low income countries, services have been fragmented by separate vertical programmes established to ensure delivery of particular technologies. We examined the effectiveness of integration strategies at the point of delivery. OBJECTIVES: To assess the effects of strategies to integrate primary health care services on producing a more coherent product and improving health care delivery and health status. SEARCH STRATEGY: We searched the Cochrane Effective Practice and Organisation of Care Group specialised register (August 2005), MEDLINE (1966 to September 2005), EMBASE (1988 to 2005), Socio Files (1974 to September 2005), Popline (1970 to September 2005), HealthStar (1975 to September 2005), Cinahl (1982 to September 2005); Cab Health (1972 to 1999), International Bibliography of the Social Sciences (1970 to 1999), and reference lists of articles. We also searched the Internet and World Health Organization (WHO) library database, hand searched relevant WHO publications and contacted experts in the field. SELECTION CRITERIA: Randomised trials, controlled before and after studies, and interrupted time series analyses of integration strategies in primary health care services. Health services in high-income countries were excluded. The primary outcomes were indicators of health care delivery, user views on any measure of service coherence, and health status. We also sought information on comparative costs. DATA COLLECTION AND ANALYSIS: Two authors independently extracted data and assessed study quality. MAIN RESULTS: Three cluster randomised trials and two controlled before and after studies were included, with three types of comparison: integration by adding on an additional component to an existing service (family planning); integrated services versus single special services (for sex workers); integrated delivery systems versus a vertical service (for family planning); and packages of enhanced primary child care services (integrated management of childhood illnesses) vs. routine child care. Interventions were complex and in some studies inputs varied substantially between comparison arms. Overall, no consistent pattern emerged. Only one study attempted to assess the user's view of the service provided. AUTHORS' CONCLUSIONS: Few studies of good quality, large and with rigorous study design have been carried out to investigate strategies to promote service integration in low and middle income countries. All describe the service supply side, and none examine or measure aspects of the demand side. Future studies must also assess the client's view, as this will influence uptake of integration strategies and their effectiveness on community health.


Asunto(s)
Prestación Integrada de Atención de Salud , Países en Desarrollo , Atención Primaria de Salud/organización & administración , Niño , Servicios de Salud del Niño/organización & administración , Ensayos Clínicos como Asunto , Servicios de Planificación Familiar/organización & administración , Costos de la Atención en Salud , Humanos , Evaluación de Resultado en la Atención de Salud , Enfermedades de Transmisión Sexual/prevención & control
17.
Environ Entomol ; 45(4): 983-90, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27257121

RESUMEN

Harvester ants can be the dominant seed predators on plants by collecting and eating seeds and are known to influence plant communities. Harvester ants are abundant in coastal sage scrub (CSS), and CSS is frequently invaded by several exotic plant species. This study used observations of foraging and cafeteria-style experiments to test for seed species selection by the harvester ant Pogonomyrmex rugosus Emery (Hymenoptera: Formicidae) in CSS. Analysis of foraging behavior showed that P. rugosus carried seeds of exotic Erodium cicutarium (L.) and exotic Brassica tournefortii (Gouan) on 85 and 15% of return trips to the nest (respectively), and only a very few ants carried the native seeds found within the study areas. When compared with the availability of seeds in the field, P. rugosus selected exotic E. cicutarium and avoided both native Encelia farinosa (Torrey & A. Gray) and exotic B. tournefortii. Foraging by P. rugosus had no major effect on the seed bank in the field. Cafeteria-style experiments confirmed that P. rugosus selected E. cicutarium over other available seeds. Native Eriogonum fasciculatum (Bentham) seeds were even less selected than E. farinosa and B. tournefortii.


Asunto(s)
Hormigas/fisiología , Especies Introducidas , Semillas , Animales , Brassica/crecimiento & desarrollo , California , Conducta Alimentaria/fisiología , Geraniaceae/crecimiento & desarrollo , Dispersión de Semillas
18.
Eur J Surg Oncol ; 42(3): 426-32, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26821736

RESUMEN

AIMS: To assess the potential association between the change in diameter of colorectal liver metastases between pre-operative imaging and liver resection and disease-free survival in patients who do not receive pre-operative liver-directed chemotherapy. MATERIALS AND METHODS: Analysis of a prospectively maintained database of patients undergoing liver resection for colorectal liver metastases between 2005 and 2012 was undertaken. Change in tumour size was assessed by comparing the maximum tumour diameter at radiological diagnosis determined by imaging and the maximum tumour diameter measured at examination of the resected specimen in 157 patients. RESULTS: The median interval from first scan to surgery was 99 days and the median increase in tumour diameter in this interval was 38%, equivalent to a tumour doubling time (DT) of 47 days. Tumour DT prior to liver resection was longer in patients with T1 primary tumours (119 days) than T2-4 tumours (44 days) and shorter in patients undergoing repeat surgery for intra-hepatic recurrence (33 days) than before primary resection (49 days). The median disease-free survival of the whole cohort was 1.57 years (0.2-7.3) and multivariate analysis revealed no association between tumour DT prior to surgery and disease-free survival. CONCLUSIONS: The rate of growth of colorectal liver metastases prior to surgery should not be used as a prognostic factor when considering the role of resection.


Asunto(s)
Neoplasias Colorrectales/mortalidad , Hepatectomía/métodos , Neoplasias Hepáticas/mortalidad , Neoplasias Hepáticas/secundario , Recurrencia Local de Neoplasia/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Colectomía/métodos , Colectomía/mortalidad , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/cirugía , Bases de Datos Factuales , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Hepatectomía/mortalidad , Humanos , Estimación de Kaplan-Meier , Neoplasias Hepáticas/cirugía , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Invasividad Neoplásica/patología , Recurrencia Local de Neoplasia/mortalidad , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias , Cuidados Preoperatorios/métodos , Estudios Retrospectivos , Medición de Riesgo , Análisis de Supervivencia , Factores de Tiempo , Resultado del Tratamiento
19.
Forensic Sci Int ; 151(2-3): 259-65, 2005 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-15939160

RESUMEN

The bodies of socially isolated people may remain undiscovered in their own houses for prolonged periods. Occasionally the body is in situ for sufficient time to become skeletonised, or partially so. Medico-legal investigation of these cases is complicated by degradation and contamination of evidence. Thus, a multidisciplinary forensic investigation is recommended. The potential contributions of forensic pathology, anthropology, odontology and entomology are outlined here with reference to two cases that occurred in Victoria, Australia, in 2003. Forensic pathologists are often unable to determine the cause of death in skeletonised bodies, however, they may find evidence to support either a natural or unnatural mode of death, and they may describe skeletal pathology or trauma, and identify skeletal features to support radiological identification of the deceased. Anthropologists can provide supplementary evidence of skeletal trauma. Additionally, they can assess age, sex, stature and racial affiliation from skeletal remains. Odontologists can identify individuals through comparison with ante-mortem dental records; however, potential difficulties exist in identifying the treating dentist of a socially isolated person. Odontologists may also examine the teeth and oro-facial skeleton for trauma. Entomologists may estimate minimum death time and/or season of death. Entomological examination of insect remains may also confirm that a body has lain in situ for a considerable period.


Asunto(s)
Entomología , Ciencias Forenses/métodos , Aislamiento Social , Tejido Adiposo/patología , Determinación de la Edad por el Esqueleto/métodos , Determinación de la Edad por los Dientes/métodos , Anciano , Animales , Huesos/patología , Conducta Alimentaria , Femenino , Cabello/patología , Humanos , Insectos/fisiología , Masculino , Uñas/patología , Cambios Post Mortem , Caracteres Sexuales
20.
J Biol Rhythms ; 13(2): 148-58, 1998 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9554576

RESUMEN

The breeding season of wild starlings is controlled by photoperiod. Full breeding condition is attained during exposure to lengthening days in the spring, and photorefractoriness ensues. The reproductive system of starlings will not subsequently be stimulated by long day lengths until photorefractoriness is dissipated by the short day lengths experienced in the autumn and winter. Unlike most studies on avian photoperiodism, this investigation involved manipulation of light intensity of a fixed photoperiod rather than of photoperiod itself. Photosensitive starlings transferred from short days to long days of different light intensities underwent graded reproductive responses according to the light intensity they experienced. Testes size in the group in the lowest intensity (3 lux) increased faster than that in controls on short days of normal intensity, but they did not become photorefractory. Testes size increased in the groups on 13, 45, and 108 lux and subsequently became photorefractory. However, the 13- and 45-lux groups required more time to become photorefractory than did the 108-lux group. The responses observed were similar to those seen in starlings exposed to different photoperiods (e.g., 11 h light:13 h dark [11L:13D], 13L:11D, 16L:8D, 18L:6D), even though all were on the same 18L:6D photoperiod. Initially, the results appear to challenge the external coincidence model for photoperiodic time measurement, but consideration of the phase response curve of the circadian rhythm of photoinducibility in starlings and the way in which it might be affected by low light intensities refute this challenge.


Asunto(s)
Aves/fisiología , Ritmo Circadiano/efectos de la radiación , Luz , Animales , Aves/anatomía & histología , Hormona Luteinizante/sangre , Masculino , Muda/fisiología , Testículo/anatomía & histología , Tiroxina/sangre , Factores de Tiempo
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