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Why Were Dinosaurs So Big?

Why were dinosaurs so big?: originally appeared on Quora: The best answer to any question. Ask a question, get a great answer. Learn from experts and access insider knowledge. You can follow Quora on Twitter, Facebook, and Google+. Answer by Marc Srour, Invertebrate Paleontologist Image by MathKnight There is actually no uncontroversial explanation for the as-of-yet unparalleled size of dinosaurs. If you look at the distribution of large sizes in dinosaurs, one distinction becomes clear: the only dinos that were small (less than 1m) were carnivorous theropods. Except for the 70 cm Fruitadens Haagarorum, no herbivorous ornithischians were small. The evolution of teeth in ornithischian lineages proceeded along very similar lines independently, and each innovation was accompanied by a bump in body size. Teeth are merely the most fossilisable sections of the digestive system. If they changed, then the rest of the animals' physiology was also changing in such a way as to enable larger body sizes, from getting larger guts to becoming quadrupedal (the first ornithischians were small and bipedal). In turn, this leads to changing ecological opportunities, feeding on different plants, being able to eat much more at once, and thus beginning the cycle of ever-growing sizes. This would then enter into a coevolutionary back-and-forth with their theropodan predators, eventually resulting in the sauropods, tyrannosaurids, and the other giants. What were the ornithischians eating to suppor...
Source: Science - The Huffington Post - Category: Science Source Type: news

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Authors: Young Lee S, Hee Kim J, Hyun Lee J, Hwy Kim Y, Jin Cha H, Wan Kim S, Ha Paek S, Soo Shin C Abstract Although somatostatin analogues (SSAs) are recommended as the first-line medical therapy for acromegaly, dopamine agonists (DAs) are also a therapeutic option for treatment. We aimed to assess and compare the efficacies of DAs and SSAs in treating acromegaly in clinical practice. We included 89 patients with acromegaly who took DAs (bromocriptine [BCT], n = 63; cabergoline [CAB], n = 11) or SSAs (n = 15) as a primary medical therapy for more than 3 months in the Seoul National University Hospital. The CAB (4...
Source: Endocrine Journal - Category: Endocrinology Tags: Endocr J Source Type: research
Classic somatostatin analogues aimed at somatostatin receptor type 2, such as octreotide and lanreotide, represent the mainstay of medical treatment for acromegaly. These agents have the potential to decrease hormone secretion and reduce tumour size. Patients with a germline mutation in the aryl hydrocarbon receptor-interacting protein gene, AIP, develop young-onset acromegaly, poorly responsive to pharmacological therapy. In this review, we summarise the most recent studies on AIP-related pituitary adenomas, paying special attention to the causes of somatostatin resistance; the somatostatin receptor profile including type...
Source: Journal of Endocrinology - Category: Endocrinology Authors: Tags: Review Source Type: research
AbstractPurposeThe aim of this study is to investigate guideline application and colonoscopy findings in real-life practice in acromegaly.MethodsWe conducted a retrospective observational non-interventional and cross-sectional analysis on 146 patients with acromegaly (ACRO) referred to our clinic. We evaluated colonoscopy data, focusing on the correlation between colonoscopy findings and hormonal/metabolic values.ResultsThe total number of colonoscopies performed in ACRO patients increased from 6 in the period 1990 –1994 to 57 in the period 2010–2014. Colonoscopy procedures were performed according to guideline...
Source: Pituitary - Category: Endocrinology Source Type: research
Insulin resistance and the development of diabetes mellitus is a common complication of acromegaly. Prevalence of type 2 diabetes in acromegaly varies from 19 to 56% depending on the case series [1]. In acromegaly, high levels of growth hormone and subsequent stimulation of insulin-like growth factor 1 synthesis contribute to peripheral insulin resistance and the development of diabetes [2]. Although absolute insulin levels may be normal or high, the presence of severe insulin resistance may predispose to diabetic ketoacidosis.
Source: Diabetes Research and Clinical Practice - Category: Endocrinology Authors: Source Type: research
ConclusionThe risk-allele frequencies of studied polymorphisms in acromegaly were higher than in general European population. There is an association betweenFTO gene polymorphisms and HDL cholesterol concentration, suggestingFTO gene polymorphisms may be associated with higher CVD risk in patients with acromegaly.
Source: Pituitary - Category: Endocrinology Source Type: research
Key Clinical Message A 60‐year‐old man with a pre‐existing stable sacrococcygeal teratoma developed acromegaly, ectopic Cushing's syndrome, and 5HIAA secretion. To our knowledge, this represents the first reported case of ACTH and serotonin secretion, and likely GHRH or GH cosecretion, from a sacrococcygeal teratoma in an adult. A 60‐year‐old man with a pre‐existing stable sacrococcygeal teratoma developed acromegaly, ectopic Cushing's syndrome, and 5HIAA secretion. To our knowledge, this represents the first reported case of ACTH and serotonin secretion, and likely GHRH or GH cosecretion, from a sacrococcygea...
Source: Clinical Case Reports - Category: General Medicine Authors: Tags: Case Report Source Type: research
Publication date: 5 December 2017 Source:Molecular and Cellular Endocrinology, Volume 457 Author(s): S. Cannavo, F. Trimarchi, F. Ferraù Increasing evidence suggests that environmental contaminants can exert endocrine disruptors activities and that pollution exposition can have a role in tumorigenic processes. Several environmental pollutants have been shown to affect pituitary cells biology and function. The aryl hydrocarbon receptor (AHR) pathway is involved in xenobiotics' metabolism and in tumorigenesis. A deregulation of the AHR pathway could have a role in pituitary tumours' pathophysiology, especially in the...
Source: Molecular and Cellular Endocrinology - Category: Endocrinology Source Type: research
Shivacharan Patel, Jigeeshu V Divatia, Sheila Nainan MyatraJournal of Anaesthesiology Clinical Pharmacology 2017 33(3):410-411
Source: Journal of Anaesthesiology Clinical Pharmacology - Category: Anesthesiology Authors: Source Type: research
CONCLUSIONS: In this article, we summarize the pathophysiology, clinical aspects and the new diagnostic tools to better understand bone impairment in acromegaly. PMID: 28880058 [PubMed - as supplied by publisher]
Source: Minerva Endocrinologica - Category: Endocrinology Tags: Minerva Endocrinol Source Type: research
We present a 25‐year‐old man who presented with overgrowth of the right hand associated with occasional pain, numbness, and limited function who was found to have macrodystrophia lipomatosa with fibrolipomatous hamartoma of the median nerve. Reports of this condition are limited in the dermatology literature, and early recognition can lead to better outcomes.
Source: Pediatric Dermatology - Category: Dermatology Authors: Tags: Brief Report Source Type: research
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