101 research outputs found
Oldest pathology in a tetrapod bone illuminates the origin of terrestrial vertebrates
The origin of terrestrial tetrapods was a key event in vertebrate evolution, yet how and when it occurred remains obscure, due to scarce fossil evidence. Here, we show that the study of palaeopathologies, such as broken and healed bones, can help elucidate poorly understood behavioural transitions such as this. Using high-resolution finite element analysis, we demonstrate that the oldest known broken tetrapod bone, a radius of the primitive stem tetrapod Ossinodus pueri from the mid-Viséan (333 million years ago) of Australia, fractured under a high-force, impact-type loading scenario. The nature of the fracture suggests that it most plausibly occurred during a fall on land. Augmenting this are new osteological observations, including a preferred directionality to the trabecular architecture of cancellous bone. Together, these results suggest that Ossinodus, one of the first large (>2m length) tetrapods, spent a significant proportion of its life on land. Our findings have important implications for understanding the temporal, biogeographical and physiological contexts under which terrestriality in vertebrates evolved. They push the date for the origin of terrestrial tetrapods further back into the Carboniferous by at least two million years. Moreover, they raise the possibility that terrestriality in vertebrates first evolved in large tetrapods in Gondwana rather than in small European forms, warranting a re-evaluation of this important evolutionary event
Haploinsufficiency for p190B RhoGAP inhibits MMTV-Neu tumor progression
Introduction: Rho signaling regulates key cellular processes including proliferation, survival, and migration, and it has been implicated in the development of many types of cancer including breast cancer. P190B Rho GTPase activating protein (RhoGAP) functions as a major inhibitor of the Rho GTPases. P190B is required for mammary gland morphogenesis, and overexpression of p190B in the mammary gland induces hyperplastic lesions. Hence, we hypothesized that p190B may play a pivotal role in mammary tumorigenesis. Methods: To investigate the effects of loss of p190B function on mammary tumor progression, p190B heterozygous mice were crossed with an MMTV-Neu breast cancer model. Effects of p190B deficiency on tumor latency, multiplicity, growth, preneoplastic progression and metastasis were evaluated. To investigate potential differences in tumor angiogenesis between the two groups, immunohistochemistry to detect von Willebrand factor was performed and quantified. To examine gene expression of potential mediators of the angiogenic switch, an angiogenesis PCR array was utilized and results were confirmed using immunohistochemistry. Finally, reciprocal transplantation of tumor fragments was performed to determine the impact of stromal deficiency of p190B on tumor angiogenesis. Results: P190B deficiency reduced tumor penetrance (53% of mice vs. 100% of mice formed tumors) and markedly delayed tumor onset by an average of 46 weeks. Tumor multiplicity was also decreased, but an increase in the number of preneoplastic lesions was detected indicating that p190B deficiency inhibited preneoplastic progression. Angiogenesis was decreased in the p190B heterozygous tumors, and expression of a potent angiogenic inhibitor, thrombospondin-1, was elevated in mammary glands. Transplantation of tumor fragments into wild-type recipients restored tumor angiogenesis. Strikingly, tumor fragments were unable to grow when transplanted into recipients. Conclusions: These data suggest that p190B haploinsufficiency in the epithelium inhibits MMTV-Neu tumor initiation. Furthermore, p190B deficiency in the vasculature is responsible, in part, for the inhibition of MMTV-Neu tumor progression
P190B RhoGAP has pro-tumorigenic functions during MMTV-Neu mammary tumorigenesis and metastasis
Three-Dimensional Neurophenotyping of Adult Zebrafish Behavior
The use of adult zebrafish (Danio rerio) in neurobehavioral research is rapidly expanding. The present large-scale study applied the newest video-tracking and data-mining technologies to further examine zebrafish anxiety-like phenotypes. Here, we generated temporal and spatial three-dimensional (3D) reconstructions of zebrafish locomotion, globally assessed behavioral profiles evoked by several anxiogenic and anxiolytic manipulations, mapped individual endpoints to 3D reconstructions, and performed cluster analysis to reconfirm behavioral correlates of high- and low-anxiety states. The application of 3D swim path reconstructions consolidates behavioral data (while increasing data density) and provides a novel way to examine and represent zebrafish behavior. It also enables rapid optimization of video tracking settings to improve quantification of automated parameters, and suggests that spatiotemporal organization of zebrafish swimming activity can be affected by various experimental manipulations in a manner predicted by their anxiolytic or anxiogenic nature. Our approach markedly enhances the power of zebrafish behavioral analyses, providing innovative framework for high-throughput 3D phenotyping of adult zebrafish behavior
Hard-Object Feeding in Sooty Mangabeys (Cercocebus atys) and Interpretation of Early Hominin Feeding Ecology
Morphology of the dentofacial complex of early hominins has figured prominently in the inference of their dietary adaptations. Recent theoretical analysis of craniofacial morphology of Australopithecus africanus proposes that skull form in this taxon represents adaptation to feeding on large, hard objects. A modern analog for this specific dietary specialization is provided by the West African sooty mangabey, Cercocebus atys. This species habitually feeds on the large, exceptionally hard nuts of Sacoglottis gabonensis, stereotypically crushing the seed casings using their premolars and molars. This type of behavior has been inferred for A. africanus based on mathematical stress analysis and aspects of dental wear and morphology. While postcanine megadontia, premolar enlargement and thick molar enamel characterize both A. africanus and C. atys, these features are not universally associated with durophagy among living anthropoids. Occlusal microwear analysis reveals complex microwear textures in C. atys unlike those observed in A. africanus, but more closely resembling textures observed in Paranthropus robustus. Since sooty mangabeys process hard objects in a manner similar to that proposed for A. africanus, yet do so without the craniofacial buttressing characteristic of this hominin, it follows that derived features of the australopith skull are sufficient but not necessary for the consumption of large, hard objects. The adaptive significance of australopith craniofacial morphology may instead be related to the toughness, rather than the hardness, of ingested foods
Rectal Indomethacin Dose Escalation (RIDE) for Prevention of Post-ERCP Pancreatitis in High-Risk Patients: a Randomized Trial
Background
Although rectal indometacin 100 mg is effective in reducing the frequency and severity of pancreatitis after endoscopic retrograde cholangiopancreatography (ERCP) in high-risk patients, the optimal dose is unknown, and pancreatitis incidence remains high. The aim of this study was to compare the efficacy of two dose regimens of rectal indometacin on the frequency and severity of pancreatitis after ERCP in high-risk patients.
Methods
In this randomised, double-blind, comparative effectiveness trial, we enrolled patients from six tertiary medical centres in the USA. Eligible patients were those at high risk for the development of pancreatitis after ERCP. We randomly assigned eligible patients (1:1) immediately after ERCP to receive either two 50 mg indometacin suppositories and a placebo suppository (standard-dose group) or three 50 mg indometacin suppositories (high-dose group). 4 h after the procedure, patients assigned to the high-dose group received an additional 50 mg indometacin suppository, whereas patients in the standard-dose group received an additional placebo suppository. The randomisation schedule, stratified according to study centre and with no other restrictions, was computer generated by an investigator who was uninvolved in the clinical care of any participants, distributed to the sites, and kept by personnel not directly involved with the study. These same personnel were responsible for packaging the drug and placebo in opaque envelopes. Patients, study personnel, and treating physicians were masked to study group assignment. The primary outcome of the study was the development of pancreatitis after ERCP. Analyses were done on an intention-to-treat basis. This trial is registered with ClinicalTrials.gov, number NCT01912716, and enrolment is complete.
Findings
Between July 9, 2013, and March 22, 2018, 1037 eligible patients were enrolled and randomly assigned to receive either standard-dose (n=515) or high-dose indometacin (n=522). Pancreatitis after ERCP occurred in 141 (14%) of 1037 patients—76 (15%) of 515 patients in the standard-dose indometacin group and 65 (12%) of 522 patients in the high-dose indometacin group (risk ratio [RR] 1·19, 95% CI 0·87–1·61; p=0·32). We observed 19 adverse events that were potentially attributable to study drug. Clinically significant bleeding occurred in 14 (1%) of 1037 patients—six (1%) of 515 patients in the standard-dose indometacin group and eight (2%) of 522 patients in the high-dose indometacin group (p=0·79). Three (1%) of 522 patients in the high-dose indometacin group developed acute kidney injury versus none in the standard-dose group (p=0·25). A non-ST elevation myocardial infarction occurred in the standard-dose indometacin group 2 days after ERCP. A transient ischaemic attack occurred in the high-dose indometacin group 5 days after ERCP. All 19 adverse events, in addition to the 141 patients who developed pancreatitis after ERCP, were considered serious as all required admission to hospital. We observed no allergic reactions or deaths at 30 day follow-up.
Interpretation
Dose escalation to rectal indometacin 200 mg did not confer any advantage compared with the standard 100 mg regimen, with pancreatitis incidence remaining high in high-risk patients. Current practice should continue unchanged. Further research should consider the pharmacokinetics of non-steroidal anti-inflammatory drugs to determine the optimal timing of their administration to prevent pancreatitis after ERCP
Case Reports1. A Late Presentation of Loeys-Dietz Syndrome: Beware of TGFβ Receptor Mutations in Benign Joint Hypermobility
Background: Thoracic aortic aneurysms (TAA) and dissections are not uncommon causes of sudden death in young adults. Loeys-Dietz syndrome (LDS) is a rare, recently described, autosomal dominant, connective tissue disease characterized by aggressive arterial aneurysms, resulting from mutations in the transforming growth factor beta (TGFβ) receptor genes TGFBR1 and TGFBR2. Mean age at death is 26.1 years, most often due to aortic dissection. We report an unusually late presentation of LDS, diagnosed following elective surgery in a female with a long history of joint hypermobility. Methods: A 51-year-old Caucasian lady complained of chest pain and headache following a dural leak from spinal anaesthesia for an elective ankle arthroscopy. CT scan and echocardiography demonstrated a dilated aortic root and significant aortic regurgitation. MRA demonstrated aortic tortuosity, an infrarenal aortic aneurysm and aneurysms in the left renal and right internal mammary arteries. She underwent aortic root repair and aortic valve replacement. She had a background of long-standing joint pains secondary to hypermobility, easy bruising, unusual fracture susceptibility and mild bronchiectasis. She had one healthy child age 32, after which she suffered a uterine prolapse. Examination revealed mild Marfanoid features. Uvula, skin and ophthalmological examination was normal. Results: Fibrillin-1 testing for Marfan syndrome (MFS) was negative. Detection of a c.1270G > C (p.Gly424Arg) TGFBR2 mutation confirmed the diagnosis of LDS. Losartan was started for vascular protection. Conclusions: LDS is a severe inherited vasculopathy that usually presents in childhood. It is characterized by aortic root dilatation and ascending aneurysms. There is a higher risk of aortic dissection compared with MFS. Clinical features overlap with MFS and Ehlers Danlos syndrome Type IV, but differentiating dysmorphogenic features include ocular hypertelorism, bifid uvula and cleft palate. Echocardiography and MRA or CT scanning from head to pelvis is recommended to establish the extent of vascular involvement. Management involves early surgical intervention, including early valve-sparing aortic root replacement, genetic counselling and close monitoring in pregnancy. Despite being caused by loss of function mutations in either TGFβ receptor, paradoxical activation of TGFβ signalling is seen, suggesting that TGFβ antagonism may confer disease modifying effects similar to those observed in MFS. TGFβ antagonism can be achieved with angiotensin antagonists, such as Losartan, which is able to delay aortic aneurysm development in preclinical models and in patients with MFS. Our case emphasizes the importance of timely recognition of vasculopathy syndromes in patients with hypermobility and the need for early surgical intervention. It also highlights their heterogeneity and the potential for late presentation. Disclosures: The authors have declared no conflicts of interes
The Human Phenotype Ontology in 2024: phenotypes around the world.
The Human Phenotype Ontology (HPO) is a widely used resource that comprehensively organizes and defines the phenotypic features of human disease, enabling computational inference and supporting genomic and phenotypic analyses through semantic similarity and machine learning algorithms. The HPO has widespread applications in clinical diagnostics and translational research, including genomic diagnostics, gene-disease discovery, and cohort analytics. In recent years, groups around the world have developed translations of the HPO from English to other languages, and the HPO browser has been internationalized, allowing users to view HPO term labels and in many cases synonyms and definitions in ten languages in addition to English. Since our last report, a total of 2239 new HPO terms and 49235 new HPO annotations were developed, many in collaboration with external groups in the fields of psychiatry, arthrogryposis, immunology and cardiology. The Medical Action Ontology (MAxO) is a new effort to model treatments and other measures taken for clinical management. Finally, the HPO consortium is contributing to efforts to integrate the HPO and the GA4GH Phenopacket Schema into electronic health records (EHRs) with the goal of more standardized and computable integration of rare disease data in EHRs
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