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1.
Radiology ; 307(5): e222679, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37310244

RESUMO

Background Accurate breast cancer risk assessment after a negative screening result could enable better strategies for early detection. Purpose To evaluate a deep learning algorithm for risk assessment based on digital mammograms. Materials and Methods A retrospective observational matched case-control study was designed using the OPTIMAM Mammography Image Database from the National Health Service Breast Screening Programme in the United Kingdom from February 2010 to September 2019. Patients with breast cancer (cases) were diagnosed following a mammographic screening or between two triannual screening rounds. Controls were matched based on mammography device, screening site, and age. The artificial intelligence (AI) model only used mammograms at screening before diagnosis. The primary objective was to assess model performance, with a secondary objective to assess heterogeneity and calibration slope. The area under the receiver operating characteristic curve (AUC) was estimated for 3-year risk. Heterogeneity according to cancer subtype was assessed using a likelihood ratio interaction test. Statistical significance was set at P < .05. Results Analysis included patients with screen-detected (median age, 60 years [IQR, 55-65 years]; 2044 female, including 1528 with invasive cancer and 503 with ductal carcinoma in situ [DCIS]) or interval (median age, 59 years [IQR, 53-65 years]; 696 female, including 636 with invasive cancer and 54 with DCIS) breast cancer and 1:1 matched controls, each with a complete set of mammograms at the screening preceding diagnosis. The AI model had an overall AUC of 0.68 (95% CI: 0.66, 0.70), with no evidence of a significant difference between interval and screen-detected (AUC, 0.69 vs 0.67; P = .085) cancer. The calibration slope was 1.13 (95% CI: 1.01, 1.26). There was similar performance for the detection of invasive cancer versus DCIS (AUC, 0.68 vs 0.66; P = .057). The model had higher performance for advanced cancer risk (AUC, 0.72 ≥stage II vs 0.66

Assuntos
Neoplasias da Mama , Carcinoma Intraductal não Infiltrante , Humanos , Feminino , Pessoa de Meia-Idade , Neoplasias da Mama/diagnóstico por imagem , Inteligência Artificial , Estudos de Casos e Controles , Estudos Retrospectivos , Medicina Estatal
2.
Nature ; 609(7928): 677-678, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35941383
3.
Pure Appl Geophys ; 180(1): 1-22, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36590884

RESUMO

On January 15th, 2022, at approximately 4:47 pm local time (0347 UTC), several weeks of heightened activity at the Hunga volcano 65 km northwest of Tongatapu, culminated in an 11-h long violent eruption which generated a significant near-field tsunami. Although the Kingdom of Tonga lies astride a large and tsunamigenic subduction zone, it has relatively few records of significant tsunami. Assessment activities took place both remotely and locally. Between March and June 2022, a field team quantified tsunami runup and inundation on the main populated islands Tongatapu and Eua, along with several smaller islands to the north, including the Ha'apai Group. Peak tsunami heights were ~ 19 m in western Tongatapu, ~ 20 m on south-eastern Nomuka Iki island and ~ 20 m on southern Tofua, located ~ 65 km S and E and 90 km N from Hunga volcano, respectively. In western Tongatapu, the largest tsunami surge overtopped a 13-15 m-high ridge along the narrow Hihifo peninsula in several locations. Analysis of tide gauge records from Nukualofa (which lag western Tongatapu arrivals by ~ 18-20 min), suggest that initial tsunami surges were generated prior to the largest volcanic explosions at ~ 0415 UTC. Further waves were generated by ~ 0426 UTC explosions that were accompanied by air-pressure waves. Efforts to model this event are unable to reproduce the timing of the large tsunami wave that toppled a weather station and communication tower on a 13 m-high ridge on western Tongatapu after 0500 UTC. Smaller tsunami waves continued until ~ 0900, coincident with a second energetic phase of eruption, and noted by eyewitnesses on Tungua and Mango Islands. Despite an extreme level of destruction caused by this tsunami, the death toll was extraordinarily low (4 victims). Interviews with witnesses and analysis of videos posted on social media suggest that this can be attributed to the arrival of smaller 'pre tsunami' waves that prompted evacuations, heightened tsunami awareness due to tsunami activity and advisories on the day before, the absence of tourists and ongoing tsunami education efforts since the 2009 Niuatoputapu, Tonga tsunami. This event highlights an unexpectedly great hazard from volcanic tsunami worldwide, which in Tonga's case overprints an already extreme level of tectonic tsunami hazard. Education and outreach efforts should continue to emphasize the 'natural warning signs' of strong ground shaking and unusual wave and current action, and the importance of self-evacuation from coastal areas of low-lying islands. The stories of survival from this event can be used as global best practice for personal survival strategies from future tsunami. Supplementary Information: The online version contains supplementary material available at 10.1007/s00024-022-03215-5.

4.
J Cancer Educ ; 30(4): 660-3, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25510367

RESUMO

The objective of this study is to identify levels of risk awareness for breast, lung and cervical cancer, in a UK student population. A sample of male (N=62) and female (N=58) university students, mean age 21.62 years completed a questionnaire identifying which risk factors they knew for each cancer. Analysis of variance was used to compare differences in risk awareness across gender and cancer types. Risk factor awareness was highest for lung cancer (0.78), mid-range for breast cancer (0.61) and lowest for cervical cancer (0.47). Women had greater risk factor awareness (0.67) than males (0.57) across all three cancers. There is also significant belief in mythic risk factors such as stress (from 14 to 40% across the three cancers). Previous research has demonstrated that risk factor awareness increases with educational status, yet even in a university student population, in which the majority of females would have been offered the HPV vaccination, risk factor awareness for cancers is variable. More health education is needed particularly around the risk factors for cervical cancer.


Assuntos
Neoplasias da Mama/psicologia , Conhecimentos, Atitudes e Prática em Saúde , Neoplasias Pulmonares/psicologia , Estudantes/psicologia , Neoplasias do Colo do Útero/psicologia , Adulto , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/prevenção & controle , Feminino , Seguimentos , Educação em Saúde , Humanos , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/prevenção & controle , Masculino , Aceitação pelo Paciente de Cuidados de Saúde , Fatores de Risco , Inquéritos e Questionários , Reino Unido/epidemiologia , Neoplasias do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/prevenção & controle , Adulto Jovem
5.
Zoo Biol ; 33(5): 426-32, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25059915

RESUMO

Although diet-related disorders have received much attention in the zoo literature, evidence-based results on relationships between diet and disease are still rare, often due to a lack of quantitative dietary information that can be linked to clinical or necropsy reports. We investigated 24 species of captive ruminants from one facility for which quantitative feeding instructions and necropsy reports between 1991 and 2012 were available. Species were classified as grazer (GR), intermediate feeder (IM), or browser (BR). Feeding type and body mass were significantly correlated to the diet fed, with smaller and BR species receiving higher proportions of non-roughage diet items. There were no significant differences between feeding types in the occurrence of parakeratosis/ruminitis/acidosis (PRA) at necropsy, but in body condition score, with BR more often in poor and less often in excellent body condition at necropsy. While there was no direct correlation between the proportion of non-roughage diet items and PRA across species, there was a significant effect of the proportion of non-roughage diet items on PRA when body mass was also taken into account: larger species, and those that received more non-roughage diet items, had higher prevalence of PRA. The results underline that diet and lack of structured feed items can be associated with the disease complex of acidosis in ruminants, but also suggest that this is modified by factors related to animal size. These latter may include susceptibility to acidosis, or husbandry-related opportunities to monopolize non-roughage feeds and ingest higher proportions than intended by feeding instructions.


Assuntos
Acidose/veterinária , Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Animais de Zoológico , Dieta , Paraceratose/veterinária , Ruminantes/fisiologia , Gastropatias/veterinária , Acidose/epidemiologia , Criação de Animais Domésticos/métodos , Criação de Animais Domésticos/estatística & dados numéricos , Animais , Constituição Corporal/fisiologia , Peso Corporal/fisiologia , Paraceratose/epidemiologia , África do Sul/epidemiologia , Especificidade da Espécie , Gastropatias/epidemiologia , Síndrome
6.
J Zoo Wildl Med ; 45(1): 153-6, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24712175

RESUMO

A great white pelican (Pelecanus onocrotalus) was referred for assessment of a subacute-onset, nonpainful swelling located in the pectoral region. Physical examination revealed a firm, round, well-circumscribed subcutaneous mass approximately 10 cm in diameter. Cytological evaluation of a fine needle aspirate of the mass was consistent with a mesenchymal tumor. The mass was excised, and a diagnosis of xanthomatosis was made based on histopathologic results. Avian xanthomatosis is a nonneoplastic condition of unknown etiology. Possible causes of this condition include trauma, metabolic or nutritional disorders. Similar lesions were not observed in the nine conspecifics that were fed the same diet and housed in the same enclosure. To our knowledge, this is the first report of xanthomatosis in the family Pelecanidae.


Assuntos
Doenças das Aves/cirurgia , Aves , Xantomatose/veterinária , Animais , Doenças das Aves/patologia , Masculino , Xantomatose/patologia , Xantomatose/cirurgia
7.
Can J Cardiol ; 40(4): 576-584, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38007219

RESUMO

BACKGROUND: The EARLY-AF (NCT02825979), STOP AF First (NCT03118518), and Cryo-FIRST (NCT01803438) randomised controlled trials (RCTs) demonstrated that cryoballoon pulmonary vein isolation reduces atrial fibrillation (AF) recurrence compared with antiarrhythmic drugs (AADs) in patients with symptomatic paroxysmal atrial fibrillation (PAF). The present study developed a cost-effectiveness model (CEM) of first-line cryoablation compared with first-line AADs for PAF, from the Canadian health care payer's perspective. METHODS: Data from the 3 RCTs were analysed to estimate key CEM parameters. The model structure used a decision tree for the first 12 months and a Markov model with a 3-month cycle length for the remaining lifetime time horizon. Costs were set at 2023 Canadian dollars, health benefits were expressed as quality-adjusted life years (QALYs), and both were discounted 3% annually. Probabilistic sensitivity analysis (PSA) considered parameter uncertainty. RESULTS: The statistical analysis estimated that first-line cryoablation generates a 47% reduction (P < 0.001) in the rate of AF recurrence, a 73% reduction in the rate of subsequent ablation (P < 0.001), and a 4.3% (P = 0.025) increase in health-related quality of life, compared with first-line AADs. The PSA indicates that an individual treated with first-line cryoablation accrues less costs (-$3,862) and more QALYs (0.19) compared with first-line AADs. Cryoablation is cost-saving in 98.4% of PSA iterations and has a 99.9% probability of being cost-effective at a cost-effectiveness threshold of $50,000 per QALY gained. Cost-effectiveness results were robust to changes in key model parameters. CONCLUSIONS: First-line cryoballoon ablation is cost-effective when compared with AADs for patients with symptomatic PAF.


Assuntos
Fibrilação Atrial , Ablação por Cateter , Criocirurgia , Humanos , Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/cirurgia , Análise Custo-Benefício , Antiarrítmicos/uso terapêutico , Ablação por Cateter/métodos , Canadá/epidemiologia , Resultado do Tratamento , Recidiva
8.
Open Heart ; 11(1)2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38238026

RESUMO

INTRODUCTION: Three recent randomised controlled trials have demonstrated that pulmonary vein isolation as an initial rhythm control strategy with cryoablation reduces atrial arrhythmia recurrence in patients with symptomatic paroxysmal atrial fibrillation (PAF) compared with antiarrhythmic drug (AAD) therapy. The aim of this study was to evaluate the cost-effectiveness of first-line cryoablation compared with first-line AADs for treating symptomatic PAF in an English National Health Service (NHS) setting. METHODS: Individual patient-level data from 703 participants with PAF enrolled into Cryo-FIRST (Catheter Cryoablation Versus Antiarrhythmic Drug as First-Line Therapy of Paroxysmal Atrial Fibrillation), STOP AF First (Cryoballoon Catheter Ablation in an Antiarrhythmic Drug Naive Paroxysmal Atrial Fibrillation) and EARLY-AF (Early Aggressive Invasive Intervention for Atrial Fibrillation) were used to derive the parameters applied in the cost-effectiveness model (CEM). The CEM comprised a hybrid decision tree and Markov structure. The decision tree had a 1-year time horizon and was used to inform the initial health state allocation in the first cycle of the Markov model (40-year time horizon; 3-month cycle length). Health benefits were expressed in quality-adjusted life years (QALYs). Costs and benefits were discounted at 3.5% per year. Model outcomes were generated using probabilistic sensitivity analysis. RESULTS: The results estimated that cryoablation would yield more QALYs (+0.17) and higher costs (+£641) per patient over a lifetime than AADs. This produced an incremental cost-effectiveness ratio of £3783 per QALY gained. Independent of initial treatment, individuals were expected to receive ~1.2 ablations over a lifetime. There was a 45% relative reduction in time spent in AF health states for those initially treated with cryoablation. DISCUSSION: AF rhythm control with first-line cryoablation is cost effective compared with first-line AADs in an English NHS setting.


Assuntos
Fibrilação Atrial , Criocirurgia , Humanos , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/cirurgia , Análise Custo-Benefício , Medicina Estatal , Antiarrítmicos/efeitos adversos , Criocirurgia/efeitos adversos , Criocirurgia/métodos
9.
Folia Parasitol (Praha) ; 60(4): 339-52, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24261135

RESUMO

Two new species of Cylicospirura Vevers, 1922 are described from carnivores from southern Africa. Cylicospirura crocutae Junker et Mutafchiev sp. n. from Crocuta crocuta (Erxleben) in Zimbabwe is distinguished from its congeners by combinations of characters, including the presence of four cephalic and four external labial papillae, while internal labial papillae were not distinct, the presence of groups of small accessory teeth between the six large tricuspid teeth, the fifth and the sixth pairs of the caudal papillae being equidistant from the cloaca, and a large ratio of length of the muscular oesophagus to that of the glandular oesophagus. Cylicospirura pardalis Junker et Mutafchiev sp. n. from Panthera pardus (Linnaeus) in the Republic of South Africa is characterized by having tricuspid teeth with large, claw-like, abaxial cusps, four cephalic and six internal labial papillae. Based on the number of caudal papillae and the position of the vulva, the subgenera Gastronodus Singh, 1934 and Skrjabinocercina Matschulsky, 1952 are re-elevated to generic rank. Amended diagnoses are proposed for the genera Cylicospirura, Gastronodus and Skrjabinocercina. Petrowospirura lyncis Matschulsky, 1952 is recognized as valid and, together with P. petrowi Sadykhov, 1957 and P. barusi Arya, 1979, is transferred to Cylicospirura as C. lyncis (Matschulsky, 1952) Junker et Mutafchiev comb. n., C. petrowi (Sadykhov, 1957) Junker et Mutafchiev comb. n. and C. barusi (Arya, 1979) Junker et Mutafchiev comb. n., respectively.


Assuntos
Hyaenidae , Nematoides/classificação , Infecções por Nematoides/veterinária , Panthera , Animais , Nematoides/anatomia & histologia , Infecções por Nematoides/parasitologia , África do Sul/epidemiologia , Especificidade da Espécie , Zimbábue/epidemiologia
10.
J Zoo Wildl Med ; 44(4): 899-910, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24450048

RESUMO

Annual mortality events in Nile crocodiles (Crocodylus niloticus) in the Olifants River Gorge in Kruger National Park, South Africa, were experienced between 2008 and 2012, during which at least 216 crocodiles died. Live crocodiles were lethargic. Necropsy examination of 56 affected crocodiles showed dark yellow-brown firm nodules in both somatic fat and the abdominal fat body. In all of the 11 crocodiles submitted for histology, degenerative, necrotic, and inflammatory changes supported a diagnosis of steatitis in both fat types. Crocodiles are apex predators in this anthropogenically changed aquatic ecosystem that is used by humans upstream and downstream from the park for domestic, agricultural, fishing, and recreational purposes. This pathologic review of pansteatitis in crocodiles in the Olifants River system was part of a broad multidisciplinary research program. To date, no definitive causative agent has been identified. Epidemiologic evidence suggests that this event may have been a one-time event with long-standing repercussions on the health of the crocodiles. Pathologic findings are rarely documented in wild crocodilians. This study also reports on other conditions, including the presence of coccidian oocysts, capillarid and filaroid nematodes, digenetic trematodes, and pentastomes.


Assuntos
Jacarés e Crocodilos , Esteatite/mortalidade , Tecido Adiposo/patologia , Animais , Ecossistema , Feminino , Masculino , África do Sul/epidemiologia , Esteatite/epidemiologia , Esteatite/etiologia , Temperatura
11.
Children (Basel) ; 10(3)2023 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-36980132

RESUMO

The combination of perinatal acidemia with postnatal hyperoxia is associated with a higher incidence of hypoxic-ischemic encephalopathy (HIE) in newborn infants. In neonatal cardiac arrest, current International Liaison Committee on Resuscitation (ILCOR) and Neonatal Resuscitation Program (NRP) guidelines recommend increasing inspired O2 to 100% during chest compressions (CC). Following the return of spontaneous circulation (ROSC), gradual weaning from 100% O2 based on pulse oximetry (SpO2) can be associated with hyperoxia and risk for cerebral tissue injury owing to oxidative stress. We hypothesize that compared to gradual weaning from 100% O2 with titration based on preductal SpO2, abrupt or rapid weaning of inspired O2 to 21% after ROSC or use of 21% O2 during CC followed by upward titration of inspired O2 to achieve target SpO2 after ROSC will limit hyperoxia after ROSC. Nineteen lambs were randomized before delivery and asphyxial arrest was induced by umbilical cord occlusion. There was no difference in oxygenation during chest compressions between the three groups. Gradual weaning of inspired O2 from 100% O2 after ROSC resulted in supraphysiological PaO2 and higher cerebral oxygen delivery compared to 21% O2 during CC or 100% O2 during CC followed by abrupt weaning to 21% O2 after ROSC. The use of 21% O2 during CC was associated with very low PaO2 after ROSC and higher brain tissue lactic acid compared to other groups. Our findings support the current recommendations to use 100% O2 during CC and additionally suggest the benefit of abrupt decrease in inspired oxygen to 21% O2 after ROSC. Clinical studies are warranted to investigate optimal oxygen titration after chest compressions and ROSC during neonatal resuscitation.

12.
Heart Rhythm O2 ; 4(9): 528-537, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37744940

RESUMO

Background: Three recent randomized controlled trials have demonstrated that, as an initial rhythm control strategy, first-line cryoballoon ablation (cryoablation) reduces atrial arrhythmia recurrence compared with antiarrhythmic drugs (AADs) in patients with symptomatic paroxysmal atrial fibrillation (PAF). Objective: The study sought to evaluate the cost-effectiveness of first-line cryoablation compared with first-line AADs for treating symptomatic PAF from a U.S. Medicare payer perspective. Methods: Individual patient-level data from 703 participants with PAF enrolled into the Cryo-FIRST (NCT01803438), STOP AF First (NCT03118518), and EARLY-AF (NCT02825979) trials were used to derive parameters for the cost-effectiveness model. The cost-effectiveness model used a hybrid decision tree and Markov structure. The decision tree had a 1-year time horizon and was used to inform the initial health state allocation in the first cycle of the Markov model. The Markov model used a 40-year time horizon (3-month cycle length). Health benefits were expressed in quality-adjusted life years (QALYs). Costs and benefits were discounted at 3% per year. Results: Cryoablation was estimated to yield higher QALYs (+0.17) and higher costs (+$4274) per patient over a 40-year time horizon than AADs. Ultimately, this produced an average incremental cost-effectiveness ratio of $24,637 per QALY gained. Independent of initial treatment, individuals were expected to receive ∼1.2 ablations over a lifetime. There was a 45% relative reduction in time spent in atrial fibrillation health states for those initially treated with cryoablation compared with AADs. Conclusion: Initial rhythm control with first-line cryoballoon ablation is highly cost-effective compared with first-line AADs from a U.S. Medicare payer perspective.

13.
Nat Commun ; 14(1): 7881, 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38036504

RESUMO

The impacts of large terrestrial volcanic eruptions are apparent from satellite monitoring and direct observations. However, more than three quarters of all volcanic outputs worldwide lie submerged beneath the ocean, and the risks they pose to people, infrastructure, and benthic ecosystems remain poorly understood due to inaccessibility and a lack of detailed observations before and after eruptions. Here, comparing data acquired between 2015 - 2017 and 3 months after the January 2022 eruption of Hunga Volcano, we document the far-reaching and diverse impacts of one of the most explosive volcanic eruptions ever recorded. Almost 10 km3 of seafloor material was removed during the eruption, most of which we conclude was redeposited within 20 km of the caldera by long run-out seafloor density currents. These powerful currents damaged seafloor cables over a length of >100 km, reshaped the seafloor, and caused mass-mortality of seafloor life. Biological (mega-epifaunal invertebrate) seafloor communities only survived the eruption where local topography provided a physical barrier to density currents (e.g., on nearby seamounts). While the longer-term consequences of such a large eruption for human, ecological and climatic systems are emerging, we expect that these previously-undocumented refugia will play a key role in longer-term ecosystem recovery.

14.
Science ; 381(6662): 1085-1092, 2023 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-37676954

RESUMO

Volcanic eruptions on land create hot and fast pyroclastic density currents, triggering tsunamis or surges that travel over water where they reach the ocean. However, no field study has documented what happens when large volumes of erupted volcanic material are instead delivered directly into the ocean. We show how the rapid emplacement of large volumes of erupted material onto steep submerged slopes triggered extremely fast (122 kilometers per hour) and long-runout (>100 kilometers) seafloor currents. These density currents were faster than those triggered by earthquakes, floods, or storms, and they broke seafloor cables, cutting off a nation from the rest of the world. The deep scours excavated by these currents are similar to those around many submerged volcanoes, providing evidence of large eruptions at other sites worldwide.

15.
Children (Basel) ; 9(10)2022 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-36291421

RESUMO

Volume expanders are indicated in the delivery room when an asphyxiated neonate is not responding to the steps of neonatal resuscitation and has signs of shock or a history of acute blood loss. Fetal blood loss (e.g., feto-maternal hemorrhage) may contribute to perinatal asphyxia. Cord compression or a tight nuchal cord can selectively occlude a thin-walled umbilical vein, resulting in feto-placental transfusion and neonatal hypovolemia. For severe bradycardia or cardiac arrest secondary to fetal blood loss, Neonatal Resuscitation Program (NRP) recommends intravenous volume expanders (crystalloids such as normal saline or packed red blood cells) infused over 5 to 10 min. Failure to recognize hypovolemia and subsequent delay in volume replacement may result in unsuccessful resuscitation due to lack of adequate cardiac preload. However, excess volume load in the presence of myocardial dysfunction from hypoxic-ischemic injury may precipitate pulmonary edema and intraventricular hemorrhage (especially in preterm infants). Emergent circumstances and ethical concerns preclude the performance of prospective clinical studies evaluating volume replacement during neonatal resuscitation. Translational studies, observational data from registries and clinical trials are needed to investigate and understand the role of volume replacement in the delivery room in term and preterm neonates. This article is a narrative review of the causes and consequences of acute fetal blood loss and available evidence on volume replacement during neonatal resuscitation of asphyxiated neonates.

16.
J Anat ; 218(4): 375-85, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21332715

RESUMO

Despite the cheetah being the fastest living land mammal, we know remarkably little about how it attains such high top speeds (29 m s(-1)). Here we aim to describe and quantify the musculoskeletal anatomy of the cheetah forelimb and compare it to the racing greyhound, an animal of similar mass, but which can only attain a top speed of 17 m s(-1). Measurements were made of muscle mass, fascicle length and moment arms, enabling calculations of muscle volume, physiological cross-sectional area (PCSA), and estimates of joint torques and rotational velocities. Bone lengths, masses and mid-shaft cross-sectional areas were also measured. Several species differences were observed and have been discussed, such as the long fibred serratus ventralis muscle in the cheetah, which we theorise may translate the scapula along the rib cage (as has been observed in domestic cats), thereby increasing the cheetah's effective limb length. The cheetah's proximal limb contained many large PCSA muscles with long moment arms, suggesting that this limb is resisting large ground reaction force joint torques and therefore is not functioning as a simple strut. Its structure may also reflect a need for control and stabilisation during the high-speed manoeuvring in hunting. The large digital flexors and extensors observed in the cheetah forelimb may be used to dig the digits into the ground, aiding with traction when galloping and manoeuvring.


Assuntos
Acinonyx/anatomia & histologia , Membro Anterior/anatomia & histologia , Locomoção/fisiologia , Músculo Esquelético/anatomia & histologia , Animais
17.
J Anat ; 218(4): 363-74, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21062282

RESUMO

The cheetah is capable of a top speed of 29 ms(-1) compared to the maximum speed of 17 ms(-1) achieved by the racing greyhound. In this study of the hindlimb and in the accompanying paper on the forelimb we have quantified the musculoskeletal anatomy of the cheetah and greyhound and compared them to identify any differences that may account for this variation in their locomotor abilities. Specifically, bone length, mass and mid-shaft diameter were measured, along with muscle mass, fascicle lengths, pennation angles and moment arms to enable estimates of maximal isometric force, joint torques and joint rotational velocities to be calculated. Surprisingly the cheetahs had a smaller volume of hip extensor musculature than the greyhounds, and we therefore propose that the cheetah powers acceleration using its extensive back musculature. The cheetahs also had an extremely powerful psoas muscle which could help to resist the pitching moments around the hip associated with fast accelerations. The hindlimb bones were proportionally longer and heavier, enabling the cheetah to take longer strides and potentially resist higher peak limb forces. The cheetah therefore possesses several unique adaptations for high-speed locomotion and fast accelerations, when compared to the racing greyhound.


Assuntos
Acinonyx/anatomia & histologia , Membro Posterior/anatomia & histologia , Locomoção/fisiologia , Músculo Esquelético/anatomia & histologia , Animais , Feminino , Masculino , Músculo Esquelético/patologia
18.
Acad Med ; 96(9): 1302-1305, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-33788791

RESUMO

PROBLEM: In March 2020, the novel coronavirus 2019 (COVID-19) pandemic spread rapidly within the United States and began overwhelming the health care system. To conserve personal protective equipment, reduce the spread of the virus, and keep student learners safe, leaders of medical schools across the country made the difficult decision to suspend in-person clinical experiences. As medical students were sent home and hospital systems ramped up their response to the virus, many essential health care workers (HCWs) faced an immediate challenge. As "nonessential" services such as schools and daycare centers abruptly closed, HCWs serving on the frontlines in inpatient settings needed a way to both fight the pandemic and care for their children. APPROACH: Medical students at Oregon Health & Science University were able to rapidly OR organize to provide childcare for essential HCWs. For roughly 8 weeks following the state of emergency (March 13 through May 15, 2020), students used Twitter and emerging technology to match families in need of childcare with a trainee volunteer. OUTCOMES: By May 15th, the service had successfully fulfilled 181 of the 202 requests for childcare (90%) over the course of 8 weeks. Of the 181 completed childcare requests, 172 (95%) were fulfilled by an individual (1:1 volunteer-to-household pairing), and 9 (5%) were fulfilled by 2 or more volunteers. NEXT STEPS: The trainees who provided childcare will apply the skills learned (e.g., clear communication, grassroots organizing, triaging, leveraging new technology) to patient care. Broader applications for this system include organizing volunteers to conduct contract tracing or to provide public health information in languages other than English. Future research includes examining the effect of the service on the productivity, morale, and mental health of both those who provided and received childcare.


Assuntos
COVID-19 , Cuidado da Criança/organização & administração , Pessoal de Saúde , Estudantes de Medicina , Voluntários , Criança , Cuidado da Criança/métodos , Pré-Escolar , Emergências , Humanos , Lactente , Oregon , Mídias Sociais
19.
J Zoo Wildl Med ; 41(2): 291-5, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20597221

RESUMO

Nine blue duikers (Cephalophus monticola), purchased in the Malabo bushmeat market, were necropsied. Eight of the nine animals were found to have dysplastic tracheas, characterized by lateral apposition of tracheal rings, entrapment of the trachealis muscle and annular ligaments, and bunching of the tracheal epithelium. Communications with zoologic pathologists and a thorough search of the veterinary literature have not uncovered a single case of this pathologic finding. As such, this finding may represent an evolutionary marker indicative of a bottleneck that may have occurred in the history of this species of duiker, endemic to the island of Bioko, in the Gulf of Benin.


Assuntos
Antílopes , Doenças da Traqueia/veterinária , Animais , Guiné Equatorial/epidemiologia , Feminino , Masculino , Doenças da Traqueia/patologia
20.
J Zoo Wildl Med ; 40(4): 791-5, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20063828

RESUMO

A 7-yr-old African wild dog (Lycaon pictus) multiparous bitch experienced severe dystocia and death one day after the onset of parturition. Necropsy revealed three placental attachments in the right uterine horn and one in the left. A full-thickness rupture of the right horn at the middle placental attachment and an autolysed fetus free in the abdomen were present. Death was attributed to hypovolemic and endotoxemic shock after uterine rupture. Myometrium adjacent to the rupture and in the left uterine horn was subdivided into irregular pseudolobules by fibrous connective tissue tracts containing small endometrial glandular acini suggestive of adenomyosis, which may have facilitated uterine rupture. This is the first reported case of dystocia-induced uterine rupture and of adenomyosis in a wild dog.


Assuntos
Canidae , Endometriose/veterinária , Ruptura Uterina/veterinária , Animais , Animais de Zoológico , Endometriose/patologia , Evolução Fatal , Feminino , Morte Fetal/veterinária , Gravidez , Ruptura Uterina/patologia
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