116 research outputs found
Does the surgeon still have a role to play in the diagnosis and management of lymphomas?
<p>Abstract</p> <p>Background</p> <p>Over the course of the past 40 years, there have been a significant number of changes in the way in which lymphomatous disease is diagnosed and managed. With the advent of computed tomography, there is little role for staging laparotomy and the surgeon's role may now more diagnostic than therapeutic.</p> <p>Aims</p> <p>To review all cases of lymphoma diagnosed at a single institution in order determine the current role of the surgeon in the diagnosis and management of lymphoma.</p> <p>Patients and methods</p> <p>Computerized pathology records were reviewed for a five-year period 1996 to 2000 to determine all cases of lymph node biopsy (incisional or excisional) in which tissue was obtained as part of a planned procedure. Cases of incidental lymphadenopathy were thus excluded.</p> <p>Results</p> <p>A total of 297 biopsies were performed of which 62 (21%) yielded lymphomas. There were 22 females and 40 males with a median age of 58 years (range: 19–84 years). The lymphomas were classified as 80% non-Hodgkin's lymphoma, 18% Hodgkin's lymphoma and 2% post-transplant lymphoproliferative disorder. Diagnosis was established by general surgeons (n = 48), ENT surgeons (n = 9), radiologists (n = 4) and ophthalmic surgeons (n = 1). The distribution of excised lymph nodes was: cervical (n = 23), inguinal (n = 15), axillary (n = 11), intra-abdominal (n = 6), submandibular (n = 2), supraclavicular (n = 2), periorbital (n = 1), parotid (n = 1) and mediastinal (n = 1). Fine needle aspiration cytology had been performed prior to biopsy in only 32 (52%) cases and had suggested: lymphoma (n = 10), reactive changes (n = 13), normal (n = 5), inadequate (n = 4). The majority (78%) of cervical lymph nodes were subjected to FNAC prior to biopsy whilst this was performed in only 36% of non-cervical lymphadenopathy.</p> <p>Conclusion</p> <p>The study has shown that lymphoma is a relatively common cause of surgical lymphadenopathy. Given the limitations of FNAC, all suspicious lymph nodes should be biopsied following FNAC even if the FNAC is reported normal or demonstrating reactive changes only. With the more widespread application of molecular techniques, and the development of improved minimally-invasive procedures, percutaneous and endoscopic techniques may come to dominate, however, at present; the surgeon still has an important role to play in the diagnosis if not treatment of lymphomas.</p
Exhaustive exercise training enhances aerobic capacity in American alligator (Alligator mississippiensis)
The oxygen transport system in mammals is extensively remodelled in response to repeated bouts of activity, but many reptiles appear to be ‘metabolically inflexible’ in response to exercise training. A recent report showed that estuarine crocodiles (Crocodylus porosus) increase their maximum metabolic rate in response to exhaustive treadmill training, and in the present study, we confirm this response in another crocodilian, American alligator (Alligator mississippiensis). We further specify the nature of the crocodilian training response by analysing effects of training on aerobic [citrate synthase (CS)] and anaerobic [lactate dehydrogenase (LDH)] enzyme activities in selected skeletal muscles, ventricular and skeletal muscle masses and haematocrit. Compared to sedentary control animals, alligators regularly trained for 15 months on a treadmill (run group) or in a flume (swim group) exhibited peak oxygen consumption rates higher by 27 and 16%, respectively. Run and swim exercise training significantly increased ventricular mass (~11%) and haematocrit (~11%), but not the mass of skeletal muscles. However, exercise training did not alter CS or LDH activities of skeletal muscles. Similar to mammals, alligators respond to exercise training by increasing convective oxygen transport mechanisms, specifically heart size (potentially greater stroke volume) and haematocrit (increased oxygen carrying-capacity of the blood). Unlike mammals, but similar to squamate reptiles, alligators do not also increase citrate synthase activity of the skeletal muscles in response to exercise
Calf health from birth to weaning. I. General aspects of disease prevention
Calfhood diseases have a major impact on the economic viability of cattle operations. This is the first in a three part review series on calf health from birth to weaning, focusing on preventive measures. The review considers both pre- and periparturient management factors influencing calf health, colostrum management in beef and dairy calves and further nutrition and weaning in dairy calves
A doublecortin containing microtubule-associated protein is implicated in mechanotransduction in Drosophila sensory cilia
Mechanoreceptors are sensory cells that transduce mechanical stimuli into electrical signals and mediate the perception of sound, touch and acceleration. Ciliated mechanoreceptors possess an elaborate microtubule cytoskeleton that facilitates the coupling of external forces to the transduction apparatus. In a screen for genes preferentially expressed in Drosophila campaniform mechanoreceptors, we identified DCX-EMAP, a unique member of the EMAP family (echinoderm–microtubule-associated proteins) that contains two doublecortin domains. DCX-EMAP localizes to the tubular body in campaniform receptors and to the ciliary dilation in chordotonal mechanoreceptors in Johnston's organ, the fly's auditory organ. Adult flies carrying a piggyBac insertion in the DCX-EMAP gene are uncoordinated and deaf and display loss of mechanosensory transduction and amplification. Electron microscopy of mutant sensilla reveals loss of electron-dense materials within the microtubule cytoskeleton in the tubular body and ciliary dilation. Our results establish a catalogue of candidate genes for Drosophila mechanosensation and show that one candidate, DCX-EMAP, is likely to be required for mechanosensory transduction and amplification
Complex evolutionary history of the Mexican stoneroller Campostoma ornatum Girard, 1856 (Actinopterygii: Cyprinidae)
<p>Abstract</p> <p>Background</p> <p>Studies of the phylogeography of Mexican species are steadily revealing genetic patterns shared by different species, which will help to unravel the complex biogeographic history of the region. <it>Campostoma ornatum </it>is a freshwater fish endemic to montane and semiarid regions in northwest Mexico and southern Arizona. Its wide range of distribution and the previously observed morphological differentiation between populations in different watersheds make this species a useful model to investigate the biogeographic role of the Sierra Madre Occidental and to disentangle the actions of Pliocene tecto-volcanic processes <it>vs </it>Quaternary climatic change. Our phylogeographic study was based on DNA sequences from one mitochondrial gene (<it>cytb</it>, 1110 bp, n = 285) and two nuclear gene regions (S7 and RAG1, 1822 bp in total, n = 56 and 43, respectively) obtained from 18 to 29 localities, in addition to a morphological survey covering the entire distribution area. Such a dataset allowed us to assess whether any of the populations/lineages sampled deserve to be categorised as an evolutionarily significant unit.</p> <p>Results</p> <p>We found two morphologically and genetically well-differentiated groups within <it>C. ornatum</it>. One is located in the northern river drainages (Yaqui, Mayo, Fuerte, Sonora, Casas Grandes, Santa Clara and Conchos) and another one is found in the southern drainages (Nazas, Aguanaval and Piaxtla). The split between these two lineages took place about 3.9 Mya (CI = 2.1-5.9). Within the northern lineage, there was strong and significant inter-basin genetic differentiation and also several secondary dispersal episodes whit gene homogenization between drainages. Interestingly, three divergent mitochondrial lineages were found in sympatry in two northern localities from the Yaqui river basin.</p> <p>Conclusions</p> <p>Our results indicate that there was isolation between the northern and southern phylogroups since the Pliocene, which was related to the formation of the ancient Nazas River paleosystem, where the southern group originated. Within groups, a complex reticulate biogeographic history for <it>C. ornatum </it>populations emerges, following the taxon pulse theory and mainly related with Pliocene tecto-volcanic processes. In the northern group, several events of vicariance promoted by river or drainage isolation episodes were found, but within both groups, the phylogeographic patterns suggest the occurrence of several events of river capture and fauna interchange. The Yaqui River supports the most diverse populations of <it>C. ornatum</it>, with several events of dispersal and isolation within the basin. Based on our genetic results, we defined three ESUs within <it>C. ornatum </it>as a first attempt to promote the conservation of the evolutionary processes determining the genetic diversity of this species. They will likely be revealed as a valuable tool for freshwater conservation policies in northwest Mexico, where many environmental problems concerning the use of water have rapidly arisen in recent decades.</p
Welcome from the policies, socio-economic aspects, and health systems research section
At BMC Obesity, the Policies, Socio-economic Aspects, and Health Systems Research Section provides an opportunity to submit research focussed on what we need to know to support implementation of obesity policies most likely to achieve substantial, sustainable and equitable reductions in the prevalence of obesity globally. Here, we present the aims and objectives of this section, hearing from each of the Associate Editors in turn. The ambition of the Policies, Socio-economic Aspects, and Health Systems Research Section is to foster innovative research combining scientific quality with real world experience. We envisage this will include research addressing the structural drivers of obesity, solution oriented research, research addressing socio-economic inequalities in obesity and obesity prevention in low and middle income countries. We look forward to stimulating research to advance both the methods and substance required to drive uptake of effective and equitable obesity reduction policies globally
Why Are Computational Neuroscience and Systems Biology So Separate?
Despite similar computational approaches, there is surprisingly little interaction between the computational neuroscience and the systems biology research communities. In this review I reconstruct the history of the two disciplines and show that this may explain why they grew up apart. The separation is a pity, as both fields can learn quite a bit from each other. Several examples are given, covering sociological, software technical, and methodological aspects. Systems biology is a better organized community which is very effective at sharing resources, while computational neuroscience has more experience in multiscale modeling and the analysis of information processing by biological systems. Finally, I speculate about how the relationship between the two fields may evolve in the near future
Mineral Type and Solution Chemistry Affect the Structure and Composition of Actively Growing Bacterial Communities as Revealed by Bromodeoxyuridine Immunocapture and 16S rRNA Pyrosequencing
© 2016, Springer Science+Business Media New York. Understanding how minerals affect bacterial communities and their in situ activities in relation to environmental conditions are central issues in soil microbial ecology, as minerals represent essential reservoirs of inorganic nutrients for the biosphere. To determine the impact of mineral type and solution chemistry on soil bacterial communities, we compared the diversity, composition, and functional abilities of a soil bacterial community incubated in presence/absence of different mineral types (apatite, biotite, obsidian). Microcosms were prepared containing different liquid culture media devoid of particular essential nutrients, the nutrients provided only in the introduced minerals and therefore only available to the microbial community through mineral dissolution by biotic and/or abiotic processes. By combining functional screening of bacterial isolates and community analysis by bromodeoxyuridine DNA immunocapture and 16S rRNA gene pyrosequencing, we demonstrated that bacterial communities were mainly impacted by the solution chemistry at the taxonomic level and by the mineral type at the functional level. Metabolically active bacterial communities varied with solution chemistry and mineral type. Burkholderia were significantly enriched in the obsidian treatment compared to the biotite treatment and were the most effective isolates at solubilizing phosphorous or mobilizing iron, in all the treatments. A detailed analysis revealed that the 16S rRNA gene sequences of the OTUs or isolated strains assigned as Burkholderia in our study showed high homology with effective mineral-weathering bacteria previously recovered from the same experimental site
Large expert-curated database for benchmarking document similarity detection in biomedical literature search
Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency–Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research
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